• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.69-77
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• 1998

Linear displacement accuracy is one of the most important factors that determine machine tool accuracy The laser interferometer has been usually recommended for the measurement of linear displacement accuracy. In this paper, microcomputer aided measurement and compensation system has been developed for the pitch error in a CNC machine tool. For accurate pitch error calculation. the analysis code for the pitch error has been also implemented according to the international standards (ISO). The PC based automatic compensation system for the pitch error is also implemented. A new algorithm for calculating optimum value for pitch error compensation is proposed, minimizing the deviation at each target points. The development system has been applied to a practical CNC maching center and the performance has been demonstrated.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1434-1437
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• 2011

Precision measurement of silicon wafer resistivity has been using single-configuration Four-Point Probe(FPP) method. This FPP method have to applying sample size, shape and thickness correction factor for a probe pin spacing to precision measurement of silicon wafer. The deference for resistivity measurement values applied correction factor and not applied correction factor was about 1.0 % deviation. The sample size, shape and thickness correction factor for a probe pin spacing have an effects on precision measurement for resistivity of silicon wafer.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.851-859
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• 2004

This paper describes a new method for the acquisition of deviation coefficients, B and C, using a single observed deviation at a fixed compass heading. At first it discusses some problems in the synthesis of two coefficients, B and C, from various observed deviation values in the four USS warships. Then, new theories and procedures for optimal coefficients, $\^{B}\;and\;\^{C},$ are dealt with and then the validity of the proposed method are evaluated. The result of findings indicates that the approximated coefficients, $\^{B}\;and\;\^{C},$ can give optimal approximation to an single observed deviation.

• Journal of Korean Physical Therapy Science
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• v.9 no.3
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• pp.97-106
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• 2002

Purpose. This study was tried to compare the effect of the change in postural deviation caused by the pain side Subjects and Methods. Inpatients and outpatients (n=71) were selected from I hospital who have a musculoskeletal low back pain and shoulder pain without any history of the central nervous system (CNS) lesions, orthopaedic problems of the both lower extremities, or the vestibular and the visual default. For the control group, normal and healthy subjects (n=30) were selected without any history of weight bearing disorders. the weight bearing was rated by the computerized force plate. Results. 1) Postural deviation was not significant difference between patients and control group(p<0.01). But postural deviation in patients was more pronounced than control group. 2) There was significant difference of postural deviation between in patients according to the pain side(p<0.01). When the pain side was on the left side, postural deviation tended to the right. When the pain side was on the right side and vertebral body, postural deviation tended to the left. 3) There was no significant difference of postural deviation between regional pain in shoulder and regional pain in low back(p<0.01). Discussions and Conclusion. As a result, the pain, for sure, affected the good posture and its keeping process directly or/and indirectly. Therefore, as the postural deviation increases, the additional energy consumption increased by the works of the muscles to keep the good posture. Preponderated postural deviation, furthermore, could load too much to the musculoskeletal system, leading to increase the pain. The postural deviation, a result of the pain, can cause a secondary deformity of the distal area as a compensatory reaction, and this compensation actually become a cause of the musculoskeletal symptom back in a cycle. Therefore, the appropriate treatment of the musculoskeletal problem and the education of the posture correction should be given to decrease the pain, preventing the secondary deformities, and increasing muscle energy efficiency of the posture remaining muscles.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.423-429
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• 2015

Objective : The purpose of this study was to investigate the effects of a body alignment correction program on asymmetrically developed squash players. Method : 30 experienced squash players who showed asymmetric body development, after evaluation of moire topography contour line shape, were involved in the experiment. All of them were right-handed and had more than five years of experience playing squash. Variables of body composition, moire topography and EMG were statistically compared between pre- and post- application of the 12-week body alignment correction program. The program consisted of 10-minute, left-handed forehand and backhand drive movements and 36 minutes performing 12 different yoga postures. Results : First, the body alignment correction program showed significant effects on the total weight, body fat percentage, and body mass index of the participants. Second, a decrease of right side inclined angles and an increase of left side inclined angles might result in a higher left-right symmetry rate and a better left-right balance; however the data was not statistically significant. Third, the EMG left-right deviation of erector spinae and latissimus decreased and the erector spinae muscle was thought to be more essential for vertebral movement and left-right asymmetry correction. Conclusion : A body alignment correction program, including yoga and opposite side exercises, could reduce left-right asymmetry.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1266-1270
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• 2020

A code is developed to correct for the coincidence summing effect in detecting a voluminous gamma source, and this code is applied to a¹⁵²Eu standard source as a test case. The source is 1000 mL of liquid in a cylindrical shape. To calculate the coincidence summing effect, the cylindrical source is considered as 10(radial) × 8(height) sectional sources. For each sectional source, the peak efficiency and total efficiency are obtained by Monte Carlo simulation at each energy for 10 energies between 50 keV and 2000 keV. The efficiencies of each sector are then expressed as polynomials of gamma energy. To calculate the correction coefficients for the coincidence summing effect, the KORSUM code is used after modification. The magnitudes of correction are 4%-17% for the standard ¹⁵²Eu source measured in this study. The relative deviation of 4.7% before the coincidence correction is reduced to 0.8% after the correction is applied to the efficiency based on the measured gamma line. Hence, this study has shown that a new method has been developed that is applicable for correcting the coincidence effect in a voluminous source, and the method is applied to the measured data of a standard ¹⁵²Eu cylinder source.

• Archives of Plastic Surgery
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• v.32 no.1
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• pp.43-48
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• 2005

Septal deviations interfere with the nasal airflow and contribute to the deformities in the external appearance of the nose. An aesthetically and functionally satisfactory correction of severe septal deformities often requires temporary intraoperative removal of the septal cartilage for appropriate remodeling. This article describes septoplasty through dorsal approach for the correction of septal deviation. From March 2001 to April 2004, the author performed septoplasty through dorsal approach for the correction of septal deviations on 45 patients, of whom 22 of whom had nasal obstruction. Open rhinoplasty was used for dorsal approach in all patients and operation was performed under the general anesthesia or local anesthesia. The follow-up period of the patients ranged from 3 to 15 months with a mean of 10 months, and postoperative results were quite satisfactory. There was neither incidences of patients' complaints, nor any complications such as hematoma, septal perforation, supratip deformity, or recurrence. And there was some improvement of nasal obstruction in 15 patients. In conclusion, Septoplasty through dorsal approach is an effective method for the correction of septal deviation and improvement of the nasal airway obstruction.

• Korean Journal of Remote Sensing
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• v.38 no.2
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• pp.189-198
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• 2022

In this present study, we investigated the effect of the offset correction factor calculation method on the sulfur dioxide (SO₂) column density in the SO₂ retrieval algorithm of the Geostationary Environment Monitoring Spectrometer (GEMS) launched in February 2020. The GEMS operational SO₂ retrieval algorithm is the Differential Optical Absorption Spectroscopy (DOAS) - Principal Component Analysis (PCA) Hybrid algorithm. In the GEMS Hybrid algorithm, the offset correction process is essential to correct the absorption effect of ozone appearing in the SO₂ slant column density (SCD) obtained after spectral fitting using DOAS. Since the SO₂ column density may depend on the conditions for calculating the offset correction factor, it is necessary to apply an appropriate offset correction value. In this present study, the offset correction values were calculated for days with many cloud pixels and few cloud pixels, respectively. And a comparison of the SO₂ column density retrieved by applying each offset correction factor to the GEMS operational SO₂ retrieval algorithm was performed. When the offset correction value was calculated using radiance data of GEMS on a day with many cloud pixels was used, the standard deviation of the SO₂ column density around India and the Korean Peninsula, which are the edges of the GEMS observation area, was 1.27 DU, and 0.58 DU, respectively. And around Hong Kong, where there were many cloud pixels, the SO₂ standard deviation was 0.77 DU. On the other hand, when the offset correction value calculated using the GEMS data on the day with few cloud pixels was used, the standard deviation of the SO₂ column density slightly decreased around India (0.72 DU), Korean Peninsula (0.38 DU), and Hong Kong (0.44 DU). We found that the SO₂ retrieval was relatively stable compared to the SO₂ retrieval case using the offset correction value on the day with many cloud pixels. Accordingly, to minimize the uncertainty of the GEMS SO₂ retrieval algorithm and to obtain a stable retrieval, it is necessary to calculate the offset correction factor under appropriate conditions.

• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.32-40
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• 2017

In this study, an in-house program to analyze the performance degradation for gas turbines is developed using MATLAB and is validated using commercial software. This program consists of design and off-design calculations. The results of design calculation is used for reference values of off-design calculation. The off-design calculation is composed of measured and expected performance analyses, and turbine inlet temperature correction. In general, performance degradation is analyzed by comparing the results of measured and expected performance analysis. However, if gas turbine performance degrades, turbine inlet temperature might increase due to the general control logic to comply with the power demand. Therefore, it is required to consider the deviation of turbine inlet temperature from the normal value in the performance diagnosis to analyze the performance degradation exactly. In this study, a special effort is given to the correction of turbine inlet temperature. The accuracy of the developed program is confirmed by comparison with commercial software, and its capability of performance diagnosis using the turbine inlet temperature correction is demonstrated.

• Journal of Biomedical Engineering Research
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• v.11 no.1
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• pp.13-18
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• 1990

Frequency responses of ambulatory electrocardiogram systems were measured. Phase shift was assessed by our improved Wagner's method. The characteristics of the systems were found much worse than that of ordinary ECG equipment both in gain and phase responses. The decay of -3dB in amplitude observed in 0.2Hz and the lead of 45 dog in phase was observed in 0.6Hz. In order to investigate which of these 2 responses play major role in generating false S -T deviation, mathe- matical filters were Composed in a computer and actual ECGs were fed. The false S-T deviation were found to be caused mostly by enormous lead in phase, and then, the compensation circuit to diminish the lead in phase was inserted in the commercial systemes. The compensated systems showed no false deviation in S-T segment.