• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.249-254
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• 1987

This paper presents a new method for generating smooth free-form surface by local correction. B-spline surface is used for its convenience of local correction, and the direction of surface correction is fixed to the average-surface-normal direction. The surface to be corrected is approximated into a uniform cubic B-spline surface. Then, the smoothness (curvature arrows, iso-parametric lines) of the approximated surface is displayed with B-spline control points. When a control point near the region that needs correction is selected, a new point 1 mm higher than the original control point in the direction of the average surface normal is displayed. And the surface is corrected by giving the amount of control point movement interactively. Since the direction of correction is given by the program and the amount of correction is selected by the user, the method is called semiautomatic. sufficiently smooth surface can be obtained by this method. Examples are given to illustrate the method.

• Earthquakes and Structures
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• 제13권1호
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• pp.17-27
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• 2017

In this study, the characteristics of site amplification at seismic observation stations in Japan were estimated using the attenuation relationship of each station's response spectrum. Ground motion records observed after 32 earthquakes were employed to construct the attenuation relationship. The station correction factor at each KiK-net station was compared to the transfer functions between the base rock and the surface. For each station, the plot of the station correction factor versus the period was similar in shape to the graphs of the transfer function (amplitude ratio versus period). Therefore, the station correction factors are effective for evaluating site amplifications considering the period of ground shaking. In addition, the station correction factors were evaluated with respect to the average shear wave velocities using a geographic information system (GIS) dataset. Lastly, the site amplifications for specific periods were estimated throughout Japan.

• Journal of information and communication convergence engineering
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• 제20권2호
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• pp.125-130
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• 2022

In modern society, as many data are used for research or commercial purposes, the value of data is gradually increasing. In related fields, research is being actively conducted to collect valuable data, but it is difficult to collect proper data because the value of collection is determined according to the performance of existing sensors. To solve this problem, a method to effectively reduce noise has been proposed, but there is a point in which performance is degraded due to damage caused by noise. In this paper, a device capable of collecting time series data was designed to correct such data noise, and a correction technique was performed by giving an error value based on the representatively collected ultrafine dust data, and then comparing before and after Compare performance. For the correction method, Kalman, LPF, Savitzky-Golay, and Moving Average filter were used. Savitzky-Golay filter and Moving Average Filter showed excellent correction rate as an experiment. Through this, the performance of the sensor can be supplemented and it is expected that data can be effectively collected.

• Journal of Korean Neurosurgical Society
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• 제44권1호
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• pp.52-56
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• 2008

Objective : The purpose of this study was to introduce our surgical experiences of scoliosis and to evaluate the effectiveness of anterior correction and fusion in adolescent idiopathic scoliosis (AIS). Methods : Between August 2004 and August 2007, four patients with AIS were treated with anterior segmental fusion and fixation at our hospital. Mean follow-up period was 9 (6-12) months. The average age was 14.0 (13-15) years. According to Lenke classification, three patients showed Lenke 1 curve and one patient with Lenke 5 curve. Single rod instrumentation was performed in one patient, dual rod instrumentation in one patient and combined rod instrumentation in two patients. Coronal Cobb measurements were performed on all curves in thoracic, thoracolumbar and, lumbar spine and the angle of hump was measured by a scoliometer pre- and postoperatively. Results : The average operative time was 394 minutes (255-525) with an average intraoperative blood loss of 1,225 ml (1,000-1,700). The mean period of hospital stay was 19.3 days and there was no complication related to the surgery. The mean Cobb angle was reduced from $43.3^{\circ}$ to $14.8^{\circ}$ (65.8% correction) postoperatively and the rib hump corrected less than $5^{\circ}$. All patients and their parents were satisfied with the deformity correction. Conclusion : Anterior spinal correction and fusion of AIS with Lenke 1 and 5 curve showed excellent deformity correction without any complications. In particular, we recommend anterior dual rod instrumentation because of mechanical stability, better control of kyphosis, and a higher fusion rate.

• 대한족부족관절학회지
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• 제8권2호
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• pp.126-130
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• 2004

Purpose: In this study, we tried to develop the technique of osteotomy for hallux valgus. The new modified technique of osteotomy was accomplished with even more greater stability, accurate correction of the deformity and more effective than 'chevron' osteotomy in terms of correction of the deformity. Materials and Methods: Between March 1998 and December 2001, 55 cases of new modified osteotomy for hallux valgus were performed for 39 patients, 16 of whom underwent operation of both feet. Operations were made for 34 women and 5 men whose average age was 46 years old (range, $20{\sim}71$ years). Average follow up period was three years (range, $2{\sim}5$ years), and during the follow up, the patients underwent physical examination and assessment with use of the American Orthpaedic Foot and Ankle Society's hallux-metatarso-phalangealinterphalangeal scale and standard foot radiographic measurements. Results: 37 patients (53 cases) out of 39 patients (55 cases) had no pain, good cosmesis, and all of the patients were satisfied with the results of the operation. Two had occasional mild discomfort. The average score according to the hallux-metatarso-phallangeal-interphalangeal scale was 93.2 points (range, $78{\sim}100$ points). The average preoperative intermetatarsal angle was $14.4^{\circ}$, which was decreased to $7.9^{\circ}$ after the osteotomy with an average correction of $6.5^{\circ}$ and The average preoperative hallux valgus angle was $34.1^{\circ}$, which was decreased to $11.1^{\circ}$ after the osteotomy with an average correction of $23^{\circ}$. This new modified technique would prevent the angulation or shortening at the osteotomy site and it was also even more stable at osteotomy site, and could do even more effective and accurate correction of the deformity than conventional Chevron osteotomy. Conclusion: New modified chevron osteotomy for the treatment of symptomatic hallux valgus was done in 55 cases, and the results were satisfactory in all cases. This method was more stable at the osteotomy site than conventional Chevron osteotomy and was also possible to do more accurate and more effective correction of the deformity. It was also easy to control the distal fragment of first metatarsal bone.

• 한국수자원학회논문집
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• 제55권12호
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• pp.1053-1064
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• 2022

현행 면적평균 강수량 산정 방법인 티센 방법은 정확한 유역평균 강수량 산정에 있어 심각한 구조적 한계가 존재한다. 강수량계의 관측 정확도 외에, 강수량계 배치와 호우의 이동 방향에 따라서도 면적평균 강수량 산정에 오차가 발생할 수 있다. 유역이 작고 관측소 밀도가 희박한 경우 시뮬레이션 및 관측 사상 모두에서 티센 방법은 첨두 전후로 10분 사이에 유역평균 강수량이 계속 급격히 증감이 반복되는 특이한 경향 보였다. 그리고 티센 유역평균 강수량은 첨두 시점이 강우레이더와 다르게 나타났다. 유역이 작지만 관측소 밀도 비교적 높은 경우에는 전반적으로 티센 방법에 의해 톱니모양의 과대 첨두치의 경향은 나타나지 않았고 시간에 따른 변동이 유사하게 나타났다. 그러나 강우레이더 관측치와 지상 강수량계 관측치 유역평균 강수량 사이에 약 10분 정도의 연속적인 시차가 발생하였다. 강우레이더 유역평균 강수량의 지상보정 효과를 검토한 결과, 보정 후 면적평균 강수량이 보정 전 면적평균 강수량에 비해 오히려 상관이 낮게 나타나, 현행 강우레이더 지상보정 알고리즘 보정 효과가 높지 않은 것을 알 수 있었다.

• Genomics & Informatics
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• 제6권4호
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• pp.231-234
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• 2008

Precise and reliable identification of CNV is still important to fully understand the effect of CNV on genetic diversity and background of complex diseases. SNP marker has been used frequently to detect CNVs, but the analysis of SNP chip data for identifying CNV has not been well established. We compared various normalization methods for CNV analysis and suggest optimal normalization procedure for reliable CNV call. Four normal Koreans and NA10851 HapMap male samples were genotyped using Affymetrix Genome-Wide Human SNP array 5.0. We evaluated the effect of median and quantile normalization to find the optimal normalization for CNV detection based on SNP array data. We also explored the effect of Robust Multichip Average (RMA) background correction for each normalization process. In total, the following 4 combinations of normalization were tried: 1) Median normalization without RMA background correction, 2) Quantile normalization without RMA background correction, 3) Median normalization with RMA background correction, and 4) Quantile normalization with RMA background correction. CNV was called using SW-ARRAY algorithm. We applied 4 different combinations of normalization and compared the effect using intensity ratio profile, box plot, and MA plot. When we applied median and quantile normalizations without RMA background correction, both methods showed similar normalization effect and the final CNV calls were also similar in terms of number and size. In both median and quantile normalizations, RMA backgroundcorrection resulted in widening the range of intensity ratio distribution, which may suggest that RMA background correction may help to detect more CNVs compared to no correction.

• Journal of Positioning, Navigation, and Timing
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• 제11권4호
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• pp.287-295
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• 2022

The GNSS coordinate time series is used as important data for geophysical analysis such as terrestrial reference frame establishment, crustal deformation, Earth orientation parameter estimation, etc. However, various factors may cause discontinuity in the coordinate time series, which may lead to errors in the interpretation. In this paper, we describe the discontinuity in the coordinate time series due to the equipment replacement for domestic GNSS stations and discuss the change in movement magnitude and velocity vector difference in each direction before and after discontinuity correction. To do this, we used three years (2017-2019) of data from 40 GNSS stations. The average magnitude of the velocity vector in the north-south, east-west, and vertical directions before correction is -12.9±1.5, 28.0±1.9, and 4.2±7.6 mm/yr, respectively. After correction, the average moving speed in each direction was -13.0±1.0, 28.2±0.8, and 0.7±2.1 mm/yr, respectively. The average magnitudes of the horizontal GNSS velocity vectors before and after discontinuous correction was similar, but the deviation in movement size of stations decreased after correction. After equipment replacement, the change in the vertical movement occurred more than the horizontal movement variation. Moreover, the change in the magnitude of movement in each direction may also cause a change in the velocity vector, which may lead to errors in geophysical analysis.

• Archives of Plastic Surgery
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• 제41권1호
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• pp.3-11
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• 2014

Background This study aimed at overcoming the disadvantages of septal extension grafts and keeping the nasal tip as natural as possible by using different forms of the graft and additional supporting methods depending on the case. Methods Among 458 patients who received a septal extension graft from March 2008 to September 2011, 107 patients were selected who underwent at least a 6-month follow-up. Patients were categorized according to the primary objective of the operation; an upturned tip correction or tip lengthening, tip lengthening with tip projection, or retracted columella correction. Each group of patients received a different type of septal extension graft out of 3 different types of grafts based on the purpose of the operation. The evaluation of the results was made from by comparing preoperative and postoperative photographs of the tip angle, projection, and nasolabial angle. Results The average tip angle for the patients in the upturned tip correction group was reduced to 98.3 from 124.9 degrees. For the patients in the tip lengthening with tip projection group, the average tip angle was reduced to 96.8 from 122.4 degrees and the average tip projection was increased to 27.5 from 23.2 mm. The average nasolabial angle for the patients in the retracted columella correction group was increased to 94.6 from 74.8 degrees. Conclusions Sufficient nasal tip lengthening and projection could be achieved by applying a septal extension graft using the graft best suited for the group of patients categorized by surgical objective.

• 한국도로학회논문집
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• 제14권6호
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• pp.167-173
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• 2012

PURPOSES : This study is to develop speed correction factor for more realistic Level-of-Service(LOS) at multilane highway. METHODS : In this study, we compared speed difference the degree of speed reductions in actual multilane road conditions with speed reduction considering speed correction factor presented in highway capacity manual using statistical techniques. And also we presents new speed correction factor analyzing collected data at national highway No.1 (Goyang~Wolrung). RESULTS : The result of analyzing and comparing new suggested speed correction factor with speed correction factor in Korea Highway Capacity Manual (KHCM) shows RMSE (Root Mean Square Error) in new speed correction factor (RMSE 1.5) is much lower than existing speed correction factor (RMSE 13.4). New suggested speed correction can be used for analyzing Level-of-Service at multilane highway. And also we suggests improvements for analysis procedure in analyzing Level-of-Service at multilane highway CONCLUSIONS : As a result of comparing differences, we draw the causes that effect the differences in speed and suggest new speed correction factor that consider traffic volumes. It can be more rational because it uses speed correction factor which can consider more realistic traffic conditions, etc.