• Journal of Digestive Cancer Research
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• 제5권1호
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• pp.44-49
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• 2017

Background: 최근 제안된 조기위암에 대한 미세침습 치료법은 내시경점막하박리술(endoscopic submucosal dissection, ESD)혹은 종양 부위를 전층 절제(endoscopic full-thickness gastric resection, EFTGR)을 통해 위 절제를 최소화하고 동시에 복강경을 통해 감시림프절 절제(sentinel lymph node dissection, SLND)를 시행함으로써 그 가능성을 제시했었고, 이들을 각각 ESN (endoscopic submucosal dissection with laparoscopic sentinel lymph node dissection), Hybrid-NOTES (endoscopic full-thickness gastric resection with laparoscopic sentinel lymph node dissection)라고 명명하였다. 본 고에서는 림프절 전이 위험성이 높은 조기위암에 대해 이 두 치료법을 시행받은 환자들의 장기 추적 결과를 평가하고자 한다. Methods: 이 후향적 연구는 2009년 1월부터 2013년 5월 중에 ESN 혹은 Hybrid-NOTES를 시행받은 환자들이 포함되었다. Results: 총 42명의 환자들이 연구에 포함되었고, ESN 21명, Hybrid-NOTES 21명이 각각 등록되었다. ESN을 시행받은 21명 중 4명, Hybrid-NOTES를 시행받은 5명은 이 미세침습수술 후 추가 수술을 받아야 했다. 아직까지 이 수술 후 사망 환자는 없지만 ESN을 시행받은 1명의 환자에서 림프절 전이가 발견되어 항암치료를 받고 있다. Conclusion: 조기위암의 미세침습 수술인 ESN 혹은 Hybrid-NOTES는 좋은 장기 추적 결과를 보여주었다. 이 방법들은 향후 림프절 전이 위험성이 높은 조기위암에서 ESD와 gastrectomy 사이에 속한 환자들에게 좋은 치료법이 될 수 있을 거라고 생각된다.

• Journal of Advanced Marine Engineering and Technology
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• 제19권3호
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• pp.99-106
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• 1995

PWM(Pluse Width Modulation) induction motor drives are being used in greater numvers through a wide variety of industrial and commercial applications. In this paper, a new speed control algorithm (hybrid algorithm) for induction motor drives that uses regular sampled PWM and harmonic elimination PWM is presented. The hybrid algorithm in implemeted on the computer to obtain solutions from the calculation equations of the width of the pulses and the firing angles for the selected harmonic elimination. this paper describes the time delay effects and the suitable compensating methods moreover, optical transmission system for driving signals is proposed and is compared with general trnasmission system. The hybrid inverter was tested with induction motor, and these test results are shown that this hybrid inverter closely approximates and exhibits many of the desirable performance characteristic distortions and eliminated the objectionable harmonics. Finally, detailed experimental investigation of the proposed hybrid scheme in presented.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.245-248
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• 2006

Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. Accordingly, the recent research efforts are focused on the improvement of engine efficiency and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the flamelet model and Low Reynolds number $k-{\varepsilon}$ turbulent model is employed to reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect. Based on numerical results, the detailed discussions have been made for the effects of oxygen injection methods and oxygen injection flow rate on flame structure and regression rate in the vortex hybrid rocket engines

• Near Infrared Analysis
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• 제1권2호
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• pp.1-8
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• 2000

Using the net analyte signal, hybrid linear analysis was proposed to predict chemical concentration. In this paper, we select a sample from training set and apply orthogonal signal correction to obtain an improved pseudo unit spectrum for hybrid least analysis. using the mean spectrum of a calibration training set, we first show the calibration by hybrid least analysis is effective to the prediction of not only chemical concentrations but also physical property variables. Then, a pseudo unit spectrum from a training set is also tested with and without orthogonal signal correction. We use two data sets, one including five chemical concentrations and the other including ten physical property variables, to compare the performance of partial least squares and modified hybrid least analysis calibration methods. The results show that the hybrid least analysis with a selected training spectrum instead of well-measured pure spectrum still gives good performances, which is a little better than partial least squares.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.524-527
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• 2004

Hybrid rocket had many advantage with compared to solid and liquid rockets. However, the engines have not yet been used in practical rocket systems, due mainly to the disadvantage of hybrid combustion, such as low fuel regression rate. In this study, lab-scale hybrid motor was designed and manufactured. And the methods of regression rate improvement were considered. Test firings with thrusts up to 300 N were conducted with GOX and transparent PMMA. Thrust was calculated with the pressure of the combustion chamber and the regression rate was measured in with variation of oxidizer flow rate. The regression rates showed a strong dependency on GOX mass flux. The frequency analysis technique of the bulk-mode oscillation of motor was applied to a hybrid rocket motor and was based on the principle that this frequency was inversely proportional to the square root of the chamber volume. Several problems and solutions of operating hybrid rocket were presented.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.351-352
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• 2023

In order to respond to changes in the industrial environment such as the 4th industrial revolution, university education also needs active educational innovation efforts. This study proposed a construction construction hybrid curriculum that can actively utilize online education in the direction of educational innovation in domestic universities. The hybrid curriculum was based on online learning through lecture videos used in team-based learning. The hybrid curriculum additionally allows learners to choose their learning methods. In a hybrid class, learners can choose the class participation method they want from offline classroom or online real-time. Hybrid classes are considered to strengthen learners' options and take a step forward in learner-centered education.

• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.269-278
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• 2006

This paper presents the new hybrid data mining technique using error pattern, modeling of improving classification accuracy. The proposed method improves classification accuracy by combining two different supervised learning methods. The main algorithm generates error pattern modeling between the two supervised learning methods(ex: Neural Networks, Decision Tree, Logistic Regression and so on.) The Proposed modeling method has been applied to the simulation of 10,000 data sets generated by Normal and exponential random distribution. The simulation results show that the performance of proposed method is superior to the existing methods like Logistic regression and Discriminant analysis.

• Structural Engineering and Mechanics
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• 제46권3호
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• pp.403-416
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• 2013

This paper describes new optimization strategy that offers significant improvements in performance over existing methods for geometry design of frame structures. In this study, an imperialist competitive algorithm (ICA) and ant colony optimization (ACO) are combined to reach to an efficient algorithm, called Imperialist Competitive Ant Colony Optimization (ICACO). The ICACO applies the ICA for global optimization and the ACO for local search. The results of optimal geometry for three benchmark examples of frame structures, demonstrate the effectiveness and robustness of the new method presented in this work. The results indicate that the new technique has a powerful search strategies due to the modifications made in search module of ICACO. Higher rate of convergence is the superiority of the presented algorithm in comparison with the conventional mathematical methods and non hybrid heuristic methods such as ICA and particle swarm optimization (PSO).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1431-1433
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• 1987

To transmit the image data at low rate, motion compensated(MC) hybrid coding scheme is used generally. In this scheme since coder performance could be decreased when scene change happens, another prediction method must be employed. In this paper we present two prediction methods. One is using the mean of neighboring block which was already transmitted. The others is estimating the current block with the neighboring blocks. When the proposed methods are applied to the conventional Me hybrid coding scheme, it is found that SNR gain of 7 dB is achieved and bit rate can be also reduced above 30%.

• International Journal of Aeronautical and Space Sciences
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• 제2권1호
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• pp.78-92
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• 2001

In this paper, several dynamic systems are modeled using the time domain finite element method. Galerkins' Weak Principle is used to model the general second-order mechanical system, and is applied to a simple pendulum dynamics. Problems caused by approximating the final momentum are also investigated. Extending the research, some dynamic analysis methods are suggested for the hybrid coordinate systems that have both slew and flexible modes. The proposed methods are based on both Extended Hamilton's Principle and Galerkin's Weak Principle. The matrix wave equation is propagated in space domain, satisfying the geometric/natural boundary conditions. As a result, the flexible motion can be obtained compatible with the applied control input. Numerical example is shown to demonstrate the effectiveness of the proposed modeling methods for the hybrid coordinate systems.