• Bulletin of the Korean Chemical Society
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• v.11 no.6
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• pp.497-505
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• 1990

The function exp$(x^2)$erfc(x), which is often encountered in studies of electrode kinetics, is evaluated to an extended precision with 32 significant decimal digits in order to find theoretical relationships used in derivative polarography/voltammetry for a chemically-coupled electrode process. Computations with a lower precision are not successful. Evaluation of the function is accomplished by using three types of expansions for the function. Best ranges of arguments are selected for each equation for particular precisions for efficiencies. The method is successfully applied to calculate higher-order derivatives of the current-potential curves in all potential ranges for a reversible electron transfer reaction coupled with a prior chemical equilibrium (i.e., a CE type process). Various parameters that characterize the peak asymmetry (such as ratios of peak-heights, ratios of half-peak-widths, and separations in peak-potentials) are analyzed to find how kinetic and thermodynamic parameters influence shapes of the derivatives. The results from the CE process is compared with those from an EC process in which a reversible electron transfer is coupled with a follow-up homogeneous chemical reaction. The two processes exibit quite contrasting differences for values of the parameters.

• Current Optics and Photonics
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• v.6 no.3
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• pp.252-259
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• 2022

In this paper, a dual-function dynamically tunable metamaterial absorber is proposed. At frequency points of 1.545 THz and 3.21 THz, two resonance peaks with absorption amplitude of 93.8% (peak I) and 99.4% (peak II) can be achieved. By regulating the conductivity of photosensitive silicon with a pump laser, the resonance frequency of peak I switches to 1.525 THz, and that of peak II switches to 2.79 THz. By adjusting the incident polarization angle by rotating the device, absorption amplitude tuning is obtained. By introducing two degrees of regulation freedom, the absorption amplitude modulation and resonant frequency switching are simultaneously realized. More importantly, dynamic and continuous adjustment of the absorption amplitude is obtained at a fixed resonant frequency, and the modulation depth reaches 100% for both peaks. In addition, the sensing property of the proposed MMA was studied while it was used as a refractive index sensor. Compared with other results reported, our device not only has a dual-function tunable characteristic and the highest modulation depth, but also simultaneously possesses fine sensing performance.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.11
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• pp.483-493
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• 2002

The damping ratio ${\xi}$ of the unit-step response of a second-order discrete system is a function of only the location of the closed-loop poles and is not directly related to the location of the system zero. However, the peak overshoot of the response is the function of both the damping ratio ${\xi}$ and an angle ${\alpha}$, which is the phasor angle of the damped sinusoidal response and is determined by the relative location of the zero with respect to the closed-loop poles. Therefore, if the zero and the open-loop poles are relatively adjusted, through pole-zero cancellation, to maintain the desired (or designed) closed-loop poles, the damping ratio ${\xi}$ will also be maintained, while the angle ${\alpha}$ changes. Accordingly, when the closed-loop system poles are fixed, the peak overshoot is considered as a function of the angle ${\alpha}$ or the system zero location. In this paper the effects of the relative location of the zero on the system performance of a second-order discrete system is studied, and a design method of digital compensator which achieves a minimum peak overshoot while maintaining the desired system mode and the damping ratio of the unit step response is presented.

• Journal of Biomedical Engineering Research
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• v.14 no.2
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• pp.185-193
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• 1993

In this paper, the peak detection algorithm was developed for the purpose of screening of the target compounds. Algorithm is divided into searching the characteristic ion and peak detection. The heuristic knowledge about analytical chemistry was applied for the searching the characteristic ion. Peak detection was accomplished in comparison with the peak identification strings and pattern strings around the retention time. Pattern strings are composed with the number which generated by pattern identification function. The variables of pattern identification function are the codes which represent the difference of two adjacent abundances Some of the free steroids were selected to demonstrate the proposed algorithm.

• Physical Therapy Korea
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• v.29 no.3
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• pp.200-207
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• 2022

Background: The oxygen uptake efficiency slope (OUES) is the most important index for accurately measuring cardiopulmonary function in patients with acute ischemic heart disease. However, the relationship between the OUES variables and important cardiopulmonary function parameters remain unelucidated for patients with acute ischemic heart disease, which accounts for the largest proportion of heart disease. Objects: The present cross sectional clinical study aimed to determine the multiple relationships among the cardiopulmonary function variables mentioned above in adults with acute ischemic heart disease. Methods: A convenience sample of 110 adult inpatients with ischemic heart disease (age: 57.4 ± 11.3 y; 95 males, 15 females) was enrolled at the hospital cardiac rehabilitation center. The correlation between the important cardiopulmonary function indicators including peak oxygen uptake (VO₂ peak), minute ventilation (VE)/carbon dioxide production (VCO₂) slope, heart rate recovery (HRR), and ejection fraction (EF) and OUES was confirmed. Results: This study showed that OUES was highly correlated with VO₂ peak, VE/VCO₂ slope, and HRR parameters. Conclusion: The OUES can be used as an accurate indicator for cardiopulmonary function. There are other factors that influence aerobic capacity besides EF, so there is no correlation with EF. Effective cardiopulmonary rehabilitation programs can be designed based on OUES during submaximal exercise in patients with acute ischemic heart disease.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.1 no.1
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• pp.69-76
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• 1994

This study was designed and undertaken to find out the effectiveness of VAS for evaluation of general anesthetic postoperative pulmonary-function. We compared the degree of perceived pulmonary function recovery with peak expiratory flow at postoperative 72 hours of subjects. The subjects of this study were collected 38 patients who had received upper abdominal operation in St. Paul Hospital, Catholic University Medical College, and Kangnam Scared Heart Hospital and Kangdong Scared Heart Hospital, Hallym University. Data collection period was from June 15th, to August 7th, 1992. The degree of pulmonary recovery function was measured with peak expiratory at 72 hours postoperatively. The degree of perceived pulmonary function of the patient was measured with ten points visual analog scale at 72 hours postoperatively. Peak expiratory flow and visual analog score was analyzed with Pearson correlation. Peak expiratory flow was expressed as a ratio of preoperative value. The result was as follows : The recovery of pulmonary function and the degree of perceived pulmonary function of the patient at 72hours postoperatively was revealed high correlation (r=.84). The above result suggested that patients with general anesthetic upper abdominal surgery should evaluate recovery of pulmonary function making use of VAS. We know that VAS is very useful in postoperative patients. We perceived that VAS is to take up a positive attitude of patients. Nurse should furnish the nursing care objectively and scientifically to patients. As VAS was economic and simple, VAS should be adviced for wider application.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2403-2406
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• 2003

When viewing images, the relative luminance of the surround has a profound impact on the apparent contrast of the image. The dark surround causes the image elements to appear lighter than those viewed in an illuminated surround. For this reason, it is worthwhile to briefly review the general results of brightness sealing under a various viewing condition. Two of the most often cited parers on the topic of brightness scaling are Stevens-stevens and Bartleson-Breneman's function. There are, however, significant differences between the perceptual functions for simple-field and complex-field viewing. In this paper, we research the relationship between Steven's power law and Bartleson-Breneman's function. We present an appropriate brightness perception function due to TV system viewing conditions. Highlight luminance peak and absolute brightness threshold value in various adaptation levels are obtained from the proposed brightness function . Also, the luminance value of black level to produce the same contrast ratio with variety of display highlight luminance peak is obtained from the proposed brightness function.

• Physical Therapy Korea
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• v.22 no.1
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• pp.19-29
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• 2015

Impaired respiratory function is common in patients with stroke. The purpose of this study were to investigate the effectiveness of exercises and to assess forced vital capacity and peak cough flow after completion of neck stabilizing and respiratory reeducation exercises (combining diaphragmatic breathing and pursed-lip breathing exercises). The 45 participants were randomly assigned to an experimental group 1 ($n_1=15$), experimental group 2 ($n_2=15$), and a control group ($n_3=15$). All subjects performed conservative physical therapy for 30 minutes. Experimental group 1 undertook the neck stabilizing exercise and the respiratory reeducation exercise. Experimental group 2 undertook the respiratory reeducation exercise. Additional exercise did not exceed 30 minutes, five times a week for six weeks. The subjects were assessed for deep neck flexor thickness and breathing function (forced vital capacity, forced expiratory volume at one second, forced expiratory volume at one second/forced vital capacity, peak expiratory flow, and manual assisted peak cough flow) at pre-post value. The results of this study were as follows. Experimental group 1 showed a significant increase only in deep neck flexor thickness change rate (p<.05). All groups showed significant increases in forced vital capacity, forced expiratory volume at one second, and peak expiratory flow in pre-post measurement (p<.05). Experimental groups 1 and 2 showed an increase in manual assisted peak cough flow in pre-post measurement (p<.05). There was no significant difference between experimental group 1 and experimental group 2, but experimental group 1 improved more than experimental group 2 in respiratory function as a whole. In conclusion, these findings suggest that the neck stabilizing exercise in combination with the respiratory reeducation exercise can improve forced vital capacity and peak cough flow in patients with stroke.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.40-45
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• 2012

In this paper, cooling system of power transformers is proposed for temperature optimized control. We predict the peak temperature of power transformer coils using load factors and construct a cooling system using weighting function. For the optimized temperature control for power transformer, a correlation function based on the load factor of a load current and the each temperatures for winding coils, for air and for oil is presented to predict the winding-coil peak temperature. Also, the results controlled by applying the power transformer is presented.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.2
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• pp.240-257
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• 2016

This study determines the effect of 3D compression pants and Kinesio taping on muscular function of the leg during knee joint flexion and extension. Eight males participated in the experiment, wearing basic pants (BP), Kinesio taping on bare skin (KT), 3D compression pants with (KTP) and without Kinesio taping (CP). The test protocol for isokinetic muscular function was composed of four sets at three angular velocities (60, 180, $240^{\circ}/sec$) using Cybex 660. Peak torque and work per repetition of the lower limbs of eight males were analyzed from the result of Cybex. Agility and power of the subjects were examined from side step and sergeant jump. Peak torque, average power, work per repetition, force decay time of subjects wearing CP and KTP were significantly better than BP or KT, especially at low angular velocity of $60^{\circ}/sec$. The time to generate peak torque of subjects wearing BP was the longest, while the force-decay time of BP was the shortest. The application of Kinesio tape on skin did not increase muscle peak torque, work and power, but did shorten the time to generate peak torque.