• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.4
• /
• pp.765-772
• /
• 2011

In this paper, a simulation-based method is presented to dispose direction finders in three dimensional space for locating targets using the directional data. A direction finder(DF) is a military weapon that is used to find locations of targets that emit radio frequencies by operating two or more DFs simultaneously. If one or more DFs are operated in the air, the accuracy of location estimation can be enhanced by disposing them in a better configuration. By extending the line method, which is a well-known algorithm for 2-D location estimation, into 3-D space, the problem of 3-D location estimation is defined as an nonlinear programming form and solved analytically. Then the optimal disposition of DFs is considered with the presented method in which methods of simulation and search technique are combined. With the suggested algorithm for 3-D disposition of DFs, regions in which targets exist can be effectively covered so that the operation effect of DF be increased.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.11
• /
• pp.1003-1007
• /
• 2015

Depth calibration is a procedure for finding the conversion function that maps disparity data from a depth-sensing camera to actual distance information. In this paper, we present an optimal depth calibration method for Kinect$^{TM}$ sensors based on an experimental design and convex optimization. The proposed method, which utilizes multiple measurements from only two points, suggests a simplified calibration procedure. The confidence ellipsoids obtained from a series of simulations confirm that a simpler procedure produces a more reliable calibration function.

• The Korean Journal of Applied Statistics
• /
• v.13 no.2
• /
• pp.393-405
• /
• 2000

Box and Draper( 19(5) listed some properties of a design that should be considered in design selection. But it is impossible that one design criterion from optimal experimental design theory reflects many potential objectives of an experiment, because the theory was originally based on the underlying model and its strict assumption about the error structure. Therefore, when it is neces::;ary to implement multi-objective experimental design. it is common practice to balance out the several optimal design criteria so that each design criterion involved benefits in terms of its relative "high" efficiency. In this study, we proposed several composite design criteria taking the case of heteroscedastic model. WVhen the heteroscedasticity is present in the model. the well known equivalence theorem between 1)- and C-optimality no longer exists and furthermore their design characteristics are sometimes drastically different. We introduced three different design criteria for this purpose: constrained design, combined design, and minimax design criteria. While the first two methods do reflect the prior belief of experimenter, the last one does not take it into account. which is sometimes desirable. Also we extended this method to the case when there are uncertainties concerning the error structure in the model. A simple algorithm and concluslOn follow.On follow.

• Journal of the Korean Data and Information Science Society
• /
• v.25 no.6
• /
• pp.1491-1498
• /
• 2014

The major criticism of optimal experimental design is that it depends heavily on the model and its accompanying assumption that often leads the number of support points equal to the number of parameters in the model. Often in the past, a polynomial model of higher degree is assumed to handle the experimental design for the polynomial regression of lower degree. In this paper we searched the possible set of designs which are robust to the departure of the assumed model. The designs are categorized with respect to D-efficiency. The approach by O'Brien (1995) was discussed in univariate polynomial regression model setting.

• The Korean Journal of Applied Statistics
• /
• v.27 no.7
• /
• pp.1269-1278
• /
• 2014

Despite the D-optimality criterion becomes very popular in designing an experiment for nonlinear models because of theoretical foundations it provides, it is very critical that the criterion depends on the unknown parameters of the nonlinear model. But some nonlinear models turned out to be partially nonlinear in sense that the optimal design depends on the subset of parameters only. It was a strong belief that the maximin approach to find a robust design to protect against the uncertainty of parameters is not guaranteed to be successful in nonlinear models. But the maximin approach could be a success for the partial nonlinear model, because often the optimal design depends on only one unknown value of parameter, easier to handle than the full parameters. We deal with maximin approach for Michaelis-Menten model with respect to D- and $D_s$-optimality.

• Journal of KIISE:Software and Applications
• /
• v.31 no.7
• /
• pp.939-948
• /
• 2004

In this paper. we Propose a robust and fast image registration technique for motion correction in brain CT-CT angiography obtained from same patient to be taken at different time. First, the feature points of two images are respectively extracted by 3D edge detection technique, and they are converted to locally weighted 3D distance map in reference image. Second, we search the optimal location whore the cross-correlation of two edges is maximized while floating image is transformed rigidly to reference image. This optimal location is determined when the maximum value of cross-correlation does't change any more and iterates over constant number. Finally, two images are registered at optimal location by transforming floating image. In the experiment, we evaluate an accuracy and robustness using artificial image and give a visual inspection using clinical brain CT-CT angiography dataset. Our proposed method shows that two images can be registered at optimal location without converging at local maximum location robustly and rapidly by using locally weighted 3D distance map, even though we use a few number of feature points in those images.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.9
• /
• pp.1007-1013
• /
• 2011

Because of their high flexibility and durability, multilayer bellows are manufactured for use in commercial vehicles, while single-layer bellows are manufactured for use in passenger vehicles. A study based on the finite element method (FEM) and shape optimization for the single-layer bellows has been actively performed; however, until now, a study based on the FEM has rarely been performed for the multilayer bellows with gaps between the layers. This paper presents a finite-element modeling scheme for the multilayer bellows to improve simulation reliability during the evaluation of stress and flexibility. For performing shape optimization for the multilayer bellows, DOE (design of experiment) and the Kriging metamodel followed by the D-optimal method are used.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.2
• /
• pp.3-12
• /
• 2010

In previous studies, the digital measurement systems and analysis algorithms were developed by using the related techniques, such as the aerial photograph detection and high resolution satellite image process. However, these studies were limited in 2-dimensional geo-processing. Therefore, it is necessary to apply the 3-dimensional spatial information and coordinate system for higher accuracy in recognizing and locating of geo-features. The objective of this study was to develop a stochastic algorithm for the optimal sensor placement using the 3-dimensional spatial analysis method. The 3-dimensional information of the LiDAR was applied in the sensor field algorithm based on 2- and/or 3-dimensional gridded points. This study was conducted with three case studies using the optimal sensor placement algorithms; the first case was based on 2-dimensional space without obstacles(2D-non obstacles), the second case was based on 2-dimensional space with obstacles(2D-obstacles), and lastly, the third case was based on 3-dimensional space with obstacles(3D-obstacles). Finally, this study suggested the methodology for the optimal sensor placement - especially, for ground-settled sensors - using the LiDAR data, and it showed the possibility of algorithm application in the information collection using sensors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.836-839
• /
• 2016

In this paper, we propose a motion estimation method that is important in performance of video encoding. Conventional motion estimation methods have serious problems of low prediction quality and problems of much computation increase. In the paper, we propose a method that reduces unnecessary computations only using optimal candidate points, while keeping prediction quality almost similar to that of the full search. The proposed method takes only 3~5% in computational amount and has decreased prediction quality about 0~0.01dB compared with the fast full search algorithm.

• Water for future
• /
• v.14 no.2
• /
• pp.63-69
• /
• 1981

This Study is aimed at optimal sequencing of water supply projects for water demand from the application in water resources field of dynamic programming because a minimum present cost strategy for investment in water supply projects plays an important part of installation of some projects. In analysis, the relationships of the future water demand and numerous possible independent projects that are expected to meet water requirements up to some future data in Daegu city were used and future water demand were estimated from the exponential function method, the method used by the Water Works Bureau of Daegu City government which is a kind of geometric progression method and the mean value of these two methods. The results showed that the optimal sequencing of water supply projects using Dynamic Programming was reasonable and the changing of the estimation method of future water demand made a difference among optimal sequence of projects while the changing of annual rate of interest had influenced on present value cost only. In general, the best sequence for constructing the seven projects was the order of D-E-G-F-C-B-A, with the corresponding period for 33-38 years.