• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.401-405
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• 2004

Column subtraction, originally proposed by Harche and Thompson(]994), is an exact method for solving large set covering, packing and partitioning problems. Since the constraint set of ship scheduling problem(SSP) have a special structure, most instances of SSP can be solved by LP relaxation. This paper aims at applying the column subtraction method to solve SSP which can not be solved by LP relaxation. For remained instances of unsolvable ones, we subtract columns from the finale simplex table to get another integer solution in an iterative manner. Computational results having up to 10,000 0-1 variables show better performance of the column subtraction method solving the remained instances of SSP than complex branch-and-bound algorithm by LINDO.

• 한국항해항만학회지
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• 제28권2호
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• pp.129-133
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• 2004

Column subtraction, originally proposed by Harche and Thompson(1994), is an exact method for solving large set covering, packing and partitioning problems. Since the constraint set of ship scheduling problem(SSP) have a special structure, most instances of SSP can be solved by LP relaxation This paper aim, at applying the column subtraction method to solve SSP which am not be solved by LP relaxation For remained instances of unsolvable ones, we subtract columns from the finale simplex table to get another integer solution in an iterative manner. Computational results having up to 10,000 0-1 variables show better performance of the column subtraction method solving the remained instances of SSP than complex branch and-bound algorithm by LINDO.

• 치과방사선
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• 제24권2호
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• pp.347-359
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• 1994

The reproducibility of cephalography in repeated exposures were studied by tracing and photographic subtraction. The materials consisted of 50 pairs of 'same day' radiograph taken under identical conditions. The evaluation included skull, cervical column, hyoid bone, pharynx, tongue, soft tissue profile resulting 43 items in tracing, and 19 items in photographic subtraction. The results obtained from the differences between each pair were as follows: 1. The means and standard deviations by tracing of skull, cervical column, hyoid bone, pharynx, tongue, soft tissue profile were 0.34±0.62㎜, 1.02±1.59㎜, 1.37±1.78㎜, 0.55±1.16㎜, 0.51±1.51㎜, 0.15±0.3㎜ each. 2. The means and standard deviations by photographic subtraction of skull, cervical column, hyoid bone, pharynx, tongue were 0.09±0.35㎜, 0.70±0.95㎜, 1.22±1.33㎜, 0.53±0.86㎜, 0.27±0.41㎜ each.

• 대한수학교육학회지:학교수학
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• 제11권4호
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• pp.567-581
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• 2009

이 연구는 영(0)이 계산오류를 유발한다는 점에 착안하여, 0이 초등학생들의 사칙계산 수행에 어느 정도로 영향을 미치는지 분석하고자 하였다. 이를 위해 A시의 한 초등학교 3,4,5,6학년 아동 222명을 대상으로 지필검사를 실시하였다. 지필검사의 내용은 한 자리 수를 대상으로 한 기초셈, 세로뺄셈, 세로곱셈, 세로나눗셈이었다. 검사 결과, 0이 초등학생들의 계산수행에 미치는 영향이 전 영역에 해당되는 것이 아니라 개별 주제에 해당되는 지엽적인 것으로 나타났다. 예를 들면, 곱셈 구구단에서 0단의 경우, 세로 뺄셈에서 0이 연속 2회 나오는 경우, 세로곱셈에서 0이 수의 중간에 있는 경우, 피제수나 제수에 0이 있는 세로나눗셈에서는 0이 과제 난도를 어느 정도 높이는 역할을 하는 것으로 나타났다. 또한 이들 개별 영역은 고학년에서도 그 비율이 상당하여 인위적인 교수학적 처방이 요구됨을 알 수 있었다.

• 대한기계학회논문집A
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• 제26권7호
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• pp.1288-1295
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• 2002

The column-type sensing element in building and mechanical construction parts was designed as three forces and three moments sensor by attaching strain gages approximately. Compared to conventional multi-component sensor, the designed sensor has high stiffness and low cost. The radius of the column was designed analytically and compared with finite element analysis. The interference errors between components were minimized by using addition and subtraction procedure of signals. The fabricated sensor was tested by using a deadweight force standard machine and a six-component force calibration machine. The calibration results showed that the 6-component forces and moments sensor had interference error less than 7.3 % between $F_x$ and $M_x$ components, and 5.0 % in case of other components.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.837-841
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• 2001

The column-type sensing element in building and mechanical construction parts was designed as three forces and three moments sensor by attaching strain gages approximately. Compared to conventional multi-component sensor, the designed sensor can solve the problem about low stiffness and high cost. The radius of the column was designed analytically and compared with finite element analysis. The coupling errors between components were minimized by using addition and subtraction procedure of signals. The fabricated sensor was tested by using a deadweight force standard machine and a six-component force calibration machine in Korea Research Institute of Standards and Science(KRISS). The calibration showed that the multi-component force/moment sensor had coupling error less than 19.8 % between $F_x$ and $M_y$ components, and 9.0 % in case of other components.

• 생약학회지
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• 제25권1호
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• pp.59-69
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• 1994

Polygonum aviculare L. was extracted by methanol and then fractionated systematically with solvents and column chromatographic method in order to isolate ingredients with anti-lipid peroxidation and liver protectective effects. Among these fractions, ethylacetate soluble part(MWE) showed the strongest in the anti-lipid peroxidation. Furthermore, the crude subtraction(MWE 4) with Rf value near 0.42, which is separated from MWE by column chromatography using a solvent system, inhibited the lipid peroxidation of rat liver in vitro. Moreover, MWE 4 decreased GOT, GPT and TBA value compared with control and suggested high protective effects against hepatotoxicity induced by carbon tetrachloride in mice. The active compounds in MWE 4 were assumed to be flavonoid glucosides.

• Journal of Korean Neurosurgical Society
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• 제61권2호
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• pp.167-179
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• 2018

The prevalence of patients with adult spinal deformity (ASD) has been reported as high as 68%. ASD often leads to significant pain and disability. Recent emphasis has been placed on sagittal plane balance and restoring normal sagittal alignment with regards to the three dimensional deformity of ASD. Optimal sagittal alignment has been known to increase spinal biomechanical efficiency, reduce energy expenditure by maintaining a stable posture with improved load absorption, influence better bony union, and help to decelerate adjacent segment deterioration. Increasingly positive sagittal imbalance has been shown to correlate with poor functional outcome and poor self-image along with poor psychological function. Compensatory mechanisms attempt to maintain sagittal balance through pelvic rotation, alterations in lumbar lordosis as well as knee and ankle flexion at the cost of increased energy expenditure. Restoring normal spinopelvic alignment is paramount to the treatment of complex spinal deformity with sagittal imbalance. Posterior osteotomies including posterior column osteotomies, pedicle subtraction osteotomies, and posterior vertebral column resection, as well anterior column support are well known to improve sagittal alignment. Understanding of whole spinal alignment and dynamics of spinopelvic alignment is essential to restore sagittal balance while minimizing the risk of developing sagittal decompensation after surgical intervention.

• 대한임베디드공학회논문지
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• 제11권5호
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• pp.277-285
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• 2016

Moving object detection system has been an emerging research field in various advanced driver assistance systems (ADAS) and surveillance system. In this paper, we propose two optical flow based moving object detection methods at dynamic scenes. Both proposed methods consist of three successive steps; pre-processing, foreground segmentation, and post-processing steps. Two proposed methods have the same pre-processing and post-processing steps, but different foreground segmentation step. Pre-processing calculates mainly optical flow map of which each pixel has the amplitude of motion vector. Dense optical flows are estimated by using Farneback technique, and the amplitude of the motion normalized into the range from 0 to 255 is assigned to each pixel of optical flow map. In the foreground segmentation step, moving object and background are classified by using the optical flow map. Here, we proposed two algorithms. One is Gaussian mixture model (GMM) based background subtraction, which is applied on optical map. Another is adaptive thresholding based foreground segmentation, which classifies each pixel into object and background by updating threshold value column by column. Through the simulations, we show that both optical flow based methods can achieve good enough object detection performances in dynamic scenes.

• 천문학회보
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• 제37권1호
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• pp.79.2-79.2
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• 2012

This study is aim to understand the distribution and the property of LISM (local interstellar medium) using the high resolution spectra of the 26 early type stars in the five open clusters ( IC 4665, Stephenson 1, Collinder 359, Roslund 5 and Collinder 70). These spectra have been observed by BOES in Bohyunsan observatory from 2009 November to 2011 Feburary, of which resolution is 45,000. We used IRAF for the data reduction (Bias subtraction, Flat-field division, and wavelength calibration) and DECH for the deriving the equivalent widths of 4 interstellar lines - Ca II K (3934${\AA}$), Na I D (5890, 5896${\AA}$) and K I (7698${\AA}$) and the column densities of those elements in LISM toward the clusters. The results of this study provide clues for better understanding of the LISM toward these clusters.