• Journal of applied mathematics & informatics
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• 제29권3_4호
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• pp.653-668
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• 2011

This paper presents a new hybrid method for solving nonlinear complementarity problems with $P_0$-functions. It can be regarded as a combination of smoothing trust region method with ODE-based method and line search technique. A feature of the proposed method is that at each iteration, a linear system is only solved once to obtain a trial step, thus avoiding solving a trust region subproblem. Another is that when a trial step is not accepted, the method does not resolve the linear system but generates an iterative point whose step-length is defined by a line search. Under some conditions, the method is proven to be globally and superlinearly convergent. Preliminary numerical results indicate that the proposed method is promising.

• 한국전산유체공학회지
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• 제5권1호
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• pp.14-21
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• 2000

A method of two and three dimensional orthogonal grid generation with control of spacing by using the covariant Laplace equation is presented. An important feature of the methodology is its ability to control effectively the grid spacing especially near the boundaries still maintaining good orthogonality in whole field. The method is based on the concept of decomposition of the global transformation into consecutive transformation of an approximate conformal mapping and an auxiliary orthogonal mapping to have linear and uncoupled equations. Control of cell spacing is based on the concept of reference arc length, and orthogonal correction is peformed in the auxiliary domain. It is concluded that the methodology can successfully generate well controlled orthogonal grids around bodies of 2 and 3 dimensional configurations.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 1998년도 가을 학술발표논문집 Vol.25 No.2 (2)
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• pp.393-395
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• 1998

온라인 문자인식에 대한 연구는 지난 30여년에 걸쳐 수행되었지만, 무제약 필기 단어 인식에 대한 연구는 활성화 된지가 오래되지 않은 실정이다. 필기자에 따른 다양한 서체의 변이와 방대한 탐색공간, 그리고 PDA(personal digital assistant)등의 제약된 계산 능력으로 인해 학문적으로는 좋은 연구결과가 나오고 있지만 실용화에는 아직도 해결해야 할 문제가 많다. 대부분의 온라인 문자 인식 시스템에서는 인식 시스템에서는 인식 시스템 자체의 성능만으로는 인식 성능의 한계가 있기 때문에 여러 가지 외부 지식을 사용한다. 그 중 대표적인 것이 단어 사전을 이용하는 것인데, 단어 사전의 크기를 미리 줄일 수 있다면 인식기의 성능이 좋아질 수 있다. 본 연구에서는 온라인 무제약 영어 필기 단어 인식을 위한 필기 데이터의 전역적 특성을 분석하고, 각각의 특성에 따른 사전 감축 비율과 오류에 대해 연구하고자 한다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제20권2호
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• pp.123-135
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• 2016

This article deals with the pricing of Asian options under a constant elasticity of variance (CEV) model as well as a stochastic elasticity of variance (SEV) model. The CEV and SEV models are underlying asset price models proposed to overcome shortcomings of the constant volatility model. In particular, the SEV model is attractive because it can characterize the feature of volatility in risky situation such as the global financial crisis both quantitatively and qualitatively. We use an asymptotic expansion method to approximate the no-arbitrage price of an arithmetic average Asian option under both CEV and SEV models. Subsequently, the zero and non-zero constant leverage effects as well as stochastic leverage effects are compared with each other. Lastly, we investigate the SEV correction effects to the CEV model for the price of Asian options.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권8호
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• pp.1423-1443
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• 2011

Background compensation plays an important role in detecting and isolating object motion in visual tracking. Here, we propose a Genetic Hough Transform, which combines the Hough Transform and Genetic Algorithm, as a method for eliminating background motion. Our method can handle cases in which the background may contain only a few, if any, feature points. These points can be used to estimate the motion between two successive frames. In addition to dealing with featureless backgrounds, our method can successfully handle motion blur. Experimental comparisons of the results obtained using the proposed method with other methods show that the proposed approach yields a satisfactory estimate of background motion.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권12호
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• pp.4513-4532
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• 2014

Motivated by the Weber's Law, this paper proposes an efficient and robust shape descriptor based on the perceptual stimulus model, called Weber's Law Shape Descriptor (WLSD). It is based on the theory that human perception of a pattern depends not only on the change of stimulus intensity, but also on the original stimulus intensity. Invariant to scale and rotation is the intrinsic properties of WLSD. As a global shape descriptor, WLSD has far lower computation complexity while is as discriminative as state-of-art shape descriptors. Experimental results demonstrate the strong capability of the proposed method in handling shape retrieval.

• Korean Journal of Acupuncture
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• 제25권3호
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• pp.167-174
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• 2008

Objective : To make comprehensive feature of previous researches on moxibustion, then build a basis of strategy for development of moxibustion-derived therapeutics. Methods : Surveyed 326 abstraction-containing literatures from total 467 of moxibustion-related papers in PubMed and 29 papers in Korea. Analysis was performed according to distribution by study subject, number by year, nation, research method, and its efficacy. Results : Moxibustion-related researches have been rapidly increased since 2001. The main contributive country for moxibustion research was China whileas few researches was done by Korea. The main subjects of moxibustion research are associated with immunity, inflammation, neurosystem, and digestive function. The most therapeutic roles of moxibustion were on pain control, modulation of immunity, anti-fatigue and anti-stress. Conclusion : This study will help Korean Oriental medical doctors to systematically review the moxibustion researches, and to develop more competitive therapeutics using moxibustion in global CAM field.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 학술대회 논문집 전문대학교육위원
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• pp.20-23
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• 2001

This paper presents a novel design approach composed of two sequential processes for 3D magnetic shielding problems, which results in the global optimum solution in a shorter time. The feature of the proposed approach is the adoption of the specific boundary element with permeability of infinity. Assuming the permeability of infinity enables us to regard the thickness of ferromagnetic shields as infinitesimal, and thus to simplify the investigated model adequately in numerical analysis. This reduces the number of unknown variables and saves us a large amount of CPU-time for grasping the broad characteristics of the model. Some numerical results that demonstrate the validity of the proposed approach are also presented.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.119-124
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• 2004

In this study, a rotor blade of a Curtis turbine is investigated. Bezier curve is generally used to define the profile of turbine blades. However, this curve gives a feature of global control, which is not proper to a supersonic impulse turbine blade. Thus, a blade design method is developed by using B-spline curve so that local control is possible to obtain an optimized blade section. To design a Curtis turbine blade section systematically, the blade section has been changed by varying three design parameters using central composite design method. Flow analyses have been carried out for the blade sections, and the effects of design parameters are evaluated.

• 로봇학회논문지
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• 제15권3호
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• pp.205-211
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• 2020

In this paper, we propose a modified ORB-SLAM (Oriented FAST and Rotated BRIEF Simultaneous Localization And Mapping) for precise indoor navigation of a mobile robot. The exact posture and position estimation by the ORB-SLAM is not possible all the times for the indoor navigation of a mobile robot when there are not enough features in the environment. To overcome this shortcoming, additional IMU (Inertial Measurement Unit) and encoder sensors were installed and utilized to calibrate the ORB-SLAM. By fusing the global information acquired by the SLAM and the dynamic local location information of the IMU and the encoder sensors, the mobile robot can be obtained the precise navigation information in the indoor environment with few feature points. The superiority of the modified ORB-SLAM was verified to compared with the conventional algorithm by the real experiments of a mobile robot navigation in a corridor environment.