• Advances in robotics research
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• 제2권1호
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• pp.33-44
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• 2018

This paper presents a novel feature detection algorithm called depth-hybrid speeded-up robust features (DH-SURF) augmented by depth information in the speeded-up robust features (SURF) algorithm. In the keypoint detection part of classical SURF, the standard deviation of the Gaussian kernel is varied for its scale-invariance property, resulting in increased computational complexity. We propose a keypoint detection method with less variation of the standard deviation by using depth data from a red-green-blue depth (RGB-D) sensor. Our approach maintains a scale-invariance property while reducing computation time. An RGB-D simultaneous localization and mapping (SLAM) system uses a feature extraction method and depth data concurrently; thus, the system is well-suited for showing the performance of the DH-SURF method. DH-SURF was implemented on a central processing unit (CPU) and a graphics processing unit (GPU), respectively, and was validated through the real-time RGB-D SLAM.

• 대한조선학회지
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• 제21권4호
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• pp.10-20
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• 1984

When the hydrodynamic coefficients of the ship maneuvering equation are estimated by captive model test, it is difficult to take account of the scale effect between model and full scale ship. This scale effect problem can be overcome by processing the sea trial data with system identification. Extended Kalman filter is used as a system identification technique for the modification of the simulation equation as well as the estimation of hydrodynamic coefficients The phenomena of simultaneous drifting of linear coefficients occur. It is confirmed that two coefficients in each pair-$(Y_v',\;Y_r'-m'u'),\;(N_v',\;N_r')$-are simultaneously drifting and all 4 coefficients are drifting together. Particularly simultaneous drifting and 2 coefficients in each pair is more significant. It is also shown that the simultaneous drifting of 4 coefficients can be reduced by choosing the input data which have the random v'/r' curve and 4 coefficients are estimated within $2{\sim}4%$ error, which may be noise level. So, it is recommended to operate the rudder randomly in sea trial or model test for the application of system identification technique.

• 한국정보처리학회논문지
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• 제6권2호
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• pp.261-274
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• 1999

최근에 자동화된 업무처리 시스템으로써, 워크플로우 시스템에 대한 연구가 활발히 이루어지고 있다. 기존 연구에서는 태스크 자체에 시간적 특성을 고려하지 않고 태스크의 상태 변이 특성만을 고려하였다. 본 연구는 태스크의 최소 처리시간과 마감시간을 고려함으로써, 시간 제약을 포함한 워크플로우 모델링 및 검증방안을 제안한다. 이를 위해 첫째, 마감시간을 위배하지 않는 태스크의 철회에 대해 대안 태스크를 결정할 수 있는 우선 순위 함수를 제안한다. 우선 순위 함수는 대안 태스크에 대한 시간요소, 의미적 호환 수준을 고려함으로써, 가장 적절한 대안 태스크를 결정한다. 둘째, 기존 연구에서는 순차 및 병행 종속성만을 고려하였으나, 본 연구에서는 태스크간 종속성을 순차 종속성이외에 다양한 병행 종속성인 동시 수행 종속성, 동시시작 종속성, 동시종료 종속성, 간섭된 종속성, 그리고 중첩된 종속성으로 구분하여 제안한다. 셋째, 기술된 워크플로우에 존재할 수 있는 논리적 모순을 발견하기 위해 그래프를 이용한 검증기법을 제안한다.

• 한국방사선학회논문지
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• 제16권2호
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• pp.103-113
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• 2022

이 논문에서는 결합된 PET(fluorodeoxyglucose, ¹⁸F-FDG)와 MRI(magnetic nanoparticles, MNP) 조영제를 동시 PET-MRI 스캔에 사용하기 위한 가교제로 N-(p-maleimidophenyl) isocyanate를 사용하여 합성하는 방안을 제안하였다. 실험은 신경교종 줄기 세포 마우스 모델에서 결합 조영제(¹⁸F-FDG로 표지된 MNP)를 주입하기 전후에 PET-MRI 이미지를 획득하고 평가하였다. 획득한 각 영상에 대해 관심영역(ROI)을 설정한 후, 분할하여 병변의 면적을 계산하였을 때 PET 영상이 MRI 영상보다 더 크고 정확했다. 특히 동시 PET-MRI 영상은 주변 연조직과 함께 정확한 병변을 묘사하였다. 평균 및 표준편차 값은 조영제 주입 여부에 관계없이 PET 영상 또는 PET-MRI 동시 영상보다 MRI 단독 영상에서 더 높게 나타났다. 또한 동시 PET-MRI 영상값이 PET 영상보다 평균 및 표준편차 값이 높게 나타났다. ¹⁸F-FDG 라벨링된 MNP 조영제와 동시 PET-MRI 영상을 표적 영상으로 사용하고 ¹⁸F- FDG 조영제만을 원본 이미지로 사용했을 때의 피크 신호 대 잡음비(PSNR) 값은 모든 실험에서 유의미 하게 나타났다. 결론적으로 동시 PET-MRI 영상에서 결합된 ¹⁸F-FDG 표지 MNP 조영제가 유용함을 확인하였다. 다양한 핵종을 사용할 수 있는 SPECT-MRI 영상 연구를 통해 진단과 치료를 동시에 할 수 있는 제제를 개발하기 위해서는 향후 연구가 필요할 것이다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.64-67
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• 2017

Applying concurrent structure and parallel processing are a common issue for these day's programs. In this research, Dynamic Programming is used to compare the parallel performance of Go language and Intel C++ Thread Building Blocks. The experiment was performed on 4 core machine and its result contains execution time under Simultaneous Multi-Threading environment. Static Optimal Binary Search Tree was used as an example. From the result, the speed-up of Go was higher than the number of cores, and that of TBB was close to it. TBB performed better in general, but for larger scale, Go was partially faster than the other.

• 수산해양교육연구
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• 제21권2호
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• pp.278-290
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• 2009

The purpose of this study is to investigate the relationship between learning skills and cognitive functions on elementary school students. In this study CAS and Learning Skills Test(LST) were administered with 3 to 6 grade, 60 students from 5 elementary schools. The data were analyzed according to Pearson's correlation and Stepwise Multiple Regression Analysis. The results are as follows. Firstly, girls and older students showed significantly higher ability than boys and younger students on the learning skills. And girls significantly outperformed boys on the planning function and attention function and on the simultaneous cognitive function was the other way round. Secondly, learning skills were explained 41% by two variables that the planning function and the successive function which are sub factors of the cognitive function. And then, planning and successive processing effected to self-management, attention and planning to test-taking skills, successive processing and attention to class-participation skills, and successive processing to information processing.

• Journal of Ginseng Research
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• 제35권1호
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• pp.31-38
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• 2011

In order to distinguish the cultivation area of Panax ginseng, principal component analysis (PCA) using quantitative and qualitative data acquired from HPLC was carried out. A new HPLC method coupled with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous quantification of ten major ginsenosides, namely $Rh_1$, $Rg_2$, $Rg_3$, $Rg_1$, Rf, Re, Rd, $Rb_2$, Rc, and $Rb_1$ in the root of P. ginseng C. A. Meyer. Simultaneous separations of these ten ginsenosides were achieved on a carbohydrate analytical column. The mobile phase consisted of acetonitrile-water-isopropanol, and acetonitrile-water-isopropanol using a gradient elution. Distinct differences in qualitative and quantitative characteristics for ginsenosides were found between the ginseng roots produced in two different Korean cultivation areas, Ganghwa and Punggi. The ginsenoside profiles obtained via HPLC analysis were subjected to PCA. PCA score plots using two principal components (PCs) showed good separation for the ginseng roots cultivated in Ganghwa and Punggi. PC1 influenced the separation, capturing 43.6% of the variance, while PC2 affected differentiation, explaining 18.0% of the variance. The highest contribution components were ginsenoside $Rg_3$ for PC1 and ginsenoside Rf for PC2. Particularly, the PCA score plot for the small ginseng roots of six-year old, each of which was light than 147 g fresh weight, showed more distinct discrimination. PC1 influenced the separation between different sample sets, capturing 51.8% of the variance, while PC2 affected differentiation, also explaining 28.0% of the variance. The highest contribution component was ginsenoside Rf for PC1 and ginsenoside $Rg_2$ for PC2. In conclusion, the HPLC-ELSD method using a carbohydrate column allowed for the simultaneous quantification of ten major ginsenosides, and PCA analysis of the ginsenoside peaks shown on the HPLC chromatogram would be a very acceptable strategy for discrimination of the cultivation area of ginseng roots.

• 소성∙가공
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• 제15권5호
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• pp.387-394
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• 2006

In order to see the effect of die deformation on the forming analysis of sheet metals, the draw-ins, strains, and spring-backs of an automotive fender panels are numerically simulated by considering the die deformation found by the simultaneous structural analysis of press and dies. By coupling the forming analysis and the structural analysis, the die deformation is simultaneously taken into account in the forming process. Furthermore, for the consideration of load difference transferred among the upper die, punch, and blank holder due to the changes in sheet thickness, the gap elements are employed instead of the blank sheet in the structural analysis. The numerical simulation results of an automotive finder draw panel are compared with the measurements. The comparison of the forming and spring-back analysis results between the rigid die and the deformed die shows that the consideration of tool deformation can predict more accurately the forming and spring-back of sheet metals.

• 소성∙가공
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• 제18권7호
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• pp.531-537
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• 2009

The effect of blank holding force on thickness variation in simultaneous sheet forming with rectangular shape and circular has been demonstrated. Because has investigated an effect on formability of magnesium sheet, in this paper, the effect of punch radius on formability have been thinning, various crack phenomena and forming velocity. By simultaneously forming process with circular and rectangular shape, the data of simultaneously forming process with circular and rectangular shape will used to a part development such as notebook computer case, cell phone and bipolar plate of fuel cell.

• 대한의용생체공학회:의공학회지
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• 제12권4호
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• pp.303-308
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• 1991

Computer assisted cardiac mapping system has made it possible to display local activation times of the heart using a simultaneous multi-point data aquisition system, and opened an era in electrophyslology guided cardiac arrhythmia surgery especially in ventricular tachycardia. In this study, we have developed a 64 channel computerized cardiacmapping system us:ng a micro-computer for basic reasearch of electrophysiology and electrical propagation in cardiac arrhythmias. The significant tasks of this study were the simultaneous acquisition of large amount of data from 64 sites, accurate and rapid analysis, and the effective display of the analyzed data. To solve these problems, we made a 64 channel signal pre-processing board in order to amplify and fitter the raw signals. And we developed the soflu'are Yor cardiac isochronous mapping whictl is presented immediately ama computer-generated graphics. This system is expected 4o enable us to study pathophyslology of cardiac arrhythmia and to improve the results of diagnosis and surgical treatments for cardiac arrhythmia.