• 한국정밀공학회지
• /
• 제26권8호
• /
• pp.62-71
• /
• 2009

In mobile robotics, ultrasonic sensors became one of the most popular devices for collision avoidance and navigation primarily due to data robustness, the easy availability of low-cost systems, their compact size, simple circuits, and their ease in interfacing with computers. However, ultrasonic sonic sensors are subject to noise which results in inaccuracy of mapping and localization of the robot. This paper introduces a new approach to enhance environmental maps based on ultrasonic range data using linear interpolation and Newton interpolation. The simulation and experimental results show that the proposed method improves of the accuracy of the map through better distance estimation between the mobile robot and obstacles.

• International Journal of Aeronautical and Space Sciences
• /
• 제15권2호
• /
• pp.183-189
• /
• 2014

Pseudo-spectral method typically converges at an exponential rate. However, it requires a special set of fixed collocation points (CPs) to get highly accurate formulas for partial integration and differentiation. In this study, computational nodes for defining the discrete variables of states and controls are built independently of the CPs. The state and control variables at each CP, which are required to transcribe an NOCP into the corresponding NLP, are interpolated, using those variables allocated at each node. Additionally, Lagrange interpolation and spline interpolation are investigated, to provide a guideline for selecting a favorable interpolation method. The proposed techniques are applied to the solution of an NOCP using equally spaced nodes, and the computed results are compared to those using the standard PS approach, to validate the usefulness of the proposed methods.

• 대한기계학회논문집
• /
• 제19권2호
• /
• pp.433-442
• /
• 1995

For the line search of a multi-variable optimization, an efficient algorithm is presented. The algorithm sequentially employs several polynomial approximations such as 2-point quadratic interpolation, 3-point cubic interpolation/extrapolation and 4-point cubic interpolation/extrapolation. The order of polynomial function is automatically increased for improving the accuracy of approximation. The method of approximation (interpolation or extrapolation) is automatically switched by checking the slope information of the sample points. Also, for selecting the initial step length along the descent vector, a new approach is presented. The performance of the proposed method is examined by solving typical test problems such as mathematical problems, mechanical design problems and dynamic response problems.

• 제어로봇시스템학회논문지
• /
• 제8권10호
• /
• pp.874-880
• /
• 2002

A number of techniques have been proposed for 3D display using view-difference of two eyes. These methods do not express enough reality like real world. The display images have to change according to the position of a viewer to improve reality. In this paper, we present an approach for generating intermediate image between two different view images by applying new image interpolation algorithm The interpolation algorithm is designed to cope with complex shapes. The proposed image interpolation algorithm generates rotated image about vertical axes by any angle from base images. Each base image that was obtained from CCD camera has an view-angle difference of $3^{\circ}C$, $5.5^{\circ}C$, $^{\circ}C$, $22^{\circ}C$, and $45^{\circ}C$. The proposed into mediate image generation method uses the geometric analysis of image and depth information through the block-based matching method.

• Journal of Electrical Engineering and Technology
• /
• 제10권3호
• /
• pp.1188-1200
• /
• 2015

A unified numerical method for computing the quadrature weights, integration matrix, and differentiation matrix is newly developed in this study. For this purpose, a spline-like interpolation using piecewise continuous polynomials is converted into a global spline interpolation formula, with which the quadrature formulas can be derived from integration and differentiation of the transformed function in an exact manner. To prove the usefulness of the suggested approach, both the Lagrange and tension spline interpolations are represented in exactly the same form as global spline interpolation. The applicability of the proposed method on arbitrary nodes is illustrated using two different sets of nodes. A series of validations using three test functions is conducted to show the flexibility in selecting computational nodes with the present method.

• Ocean Systems Engineering
• /
• 제9권2호
• /
• pp.179-190
• /
• 2019

This paper deals with the problem of the global stabilization for a class of ocean structure systems. It is well known that, in general, the global asymptotic stability of the ocean structure subsystems does not imply the global asymptotic stability of the composite closed-loop system. The classical fuzzy inference methods cannot work to their full potential in such circumstances because given knowledge does not cover the entire problem domain. However, requirements of fuzzy systems may change over time and therefore, the use of a static rule base may affect the effectiveness of fuzzy rule interpolation due to the absence of the most concurrent (dynamic) rules. Designing a dynamic rule base yet needs additional information. In this paper, we demonstrate this proposed methodology is a flexible and general approach, with no theoretical restriction over the employment of any particular interpolation in performing interpolation nor in the computational mechanisms to implement fitness evaluation and rule promotion.

• 대한토목학회논문집
• /
• 제26권4A호
• /
• pp.677-687
• /
• 2006

크리깅 보간법은 지구통계학 분야에 주로 사용되는 보간법의 하나이다. 이 방법은 실험적 베리오그램과 이론적 베리오그램의 작성과 크리깅 보간법의 정식화에 관한 연구를 포함하고 있다. 종래의 응력복구를 위한 최소제곱법과 대조적으로, 가우스적분점에서의 응력데이타로부터 준정해를 얻기 위해 가중 최소제곱법에 기초를 둔다. 즉, 동일한 가중치를 사용하는 종래의 방식들과는 달리 가우스적분점에서의 응력값의 보간을 위하여 베리오그램 모델링을 통한 가중치가 결정된다. 한편, 분할된 요소망에 Zienkiewicz와 Zhu에 의해 제안된 SPR기법에 기초를 둔 사후오차평가를 통해 p-차수를 균등 또는 선택적으로 증가시키는 자동체눈 방식이 도입되었다. 이 방법의 정당성을 보기위해 인장력을 받는 개구부를 갖는 평판문제를 해석하였다. 또한, 기존의 최소제곱법과의 비교를 통한 크리깅보간법의 정당성을 보여 주었다.

• 전자공학회논문지S
• /
• 제35S권11호
• /
• pp.116-122
• /
• 1998

본 논문에서는 원영상이 가지고 있는 고주파 성분을 효율적으로 복원할 수 있는 공간 적응적 영상보간(image interpolation) 알고리듬을 제안한다. 영상이 갖고 있는 선험적 정보(a priori knowledge)를 보간 과정에 적용하기 위해서는, 우선 저해상도의 영상 시스템을 나타내는 분리 가능한(separable) 2차원 열화모델(degradation model)을 결정한다. 이렇게 결정된 열화 모델에 따라 다섯 가지의 서로 다른 제약 조건들을 사용하여 정칙화에 기반을 둔 공간 적응적 영상보간 알고리듬을 제안한다. 또한, 제안된 알고리듬의 수렴성을 분석하고, 실험 결과를 토대로 비적응적인 방법과 제안된 알고리듬의 성능을 비교한다.

• Journal of Multimedia Information System
• /
• 제7권3호
• /
• pp.231-238
• /
• 2020

This work presents a fully analog baseline wander tracking and removal circuitry using high-pass filter (HPF) based R-peak detection and quadratic interpolation that does not require digital post processing, thus suitable for compact and low power long-term ECG monitoring devices. The proposed method can effectively track and remove baseline wander in ECG waveforms corrupted by various motion artifacts, whereas minimizing the loss of essential features including the QRS-Complex. The key component for tracking the baseline wander is down sampling the moving average of the corrupted ECG waveform followed by quadratic interpolation, where the R-peak samples that distort the baseline tracking are excluded from the moving average by using a HPF based approach. The proposed circuit is designed using CMOS 0.18-㎛ technology (1.8V supply) with power consumption of 19.1 ㎼ and estimated area of 15.5 ㎟ using a 4^th order HPF and quadratic interpolation. Results show SNR improvement of 10 dB after removing the baseline wander from the corrupted ECG waveform.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2014년도 추계학술대회
• /
• pp.114-116
• /
• 2014

The interpolation of the missing AIS dynamic data can be used for predicting the lost data of the ship's state which is able to product the valuable information for analyzing and investigating the maritime accidents. The previous research proposed some interpolating methods however there exists some problem, firstly, the interpolated parameters such as COG, SOG, HDG weren't described sufficiently and accurately as in AIS message, secondly, each method is only suitable to some kinds of given AIS data, finally at heavy wind and current area, the parameters of AIS dynamic change quickly in short time, therefore, the modelling of the variation of ship's dynamic based on the physical characteristic is very difficult, in these cases the time-series and numerical method are usually better. This research proposes the other method through numerical analysis which can be suitable for many different kinds of the lost data, parameters are interpolated sufficiently, beside that this model is appropriate to all variation in short time interval. All the given AIS dynamic are regarded as the functions to time, then curves are established for fitting all data. Experiments are carried out to evaluate the performance of this approach, the interpolation results show this approach can be applied well in practice.