• Korea-Australia Rheology Journal
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• v.15 no.4
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• pp.197-208
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• 2003

Two measures of distributive mixing are examined: the standard deviation $\sigma$ and the maximum error E, among average concentrations of finite-sized samples. Curves of E versus sample size L are easily interpreted in terms of the size and intensity of the worst flaw in the mixture. E(L) is sensitive to the size of this flaw, regardless of the overall size of the mixture. The measures are used to study distributive mixing for time-periodic flows in a rectangular cavity, using the mapping method. Globally chaotic flows display a well-defined asymptotic behavior: E and $\sigma$ decrease exponentially with time, and the curves of E(L) and $\sigma$ (L) achieve a self-similar shape. This behavior is independent of the initial configuration of the fluids. Flows with large islands do not show self-similarity, and the final mixing result is strongly dependent on the initial fluid configuration.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1077-1080
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• 1987

Images are 2-dimensional projection of 3-dimensional scenes and many problems of scene analysis arise due to inherent depth ambiguities in a monocular 2-D image. Therefore, depth recovery is a crucial problem in image understanding. This paper proposes modified algorithm which is focused on accurate correspondnce in stereo vision. The feature we use is zero-crossing points and the similarity measure with two property evaluation function is used to estimate initial probability. And we introduce relaxation technique for accurate and global correspondence.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.428-431
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• 2004

A multi-stage hierarchical clustering technique, which is an unsupervised technique, has been proposed in this paper for classifying the hyperspectral data .. The multistage algorithm consists of two stages. The 'local' segmentor of the first stage performs region-growing segmentation by employing the hierarchical clustering procedure with the restriction that pixels in a cluster must be spatially contiguous. The 'global' segmentor of the second stage, which has not spatial constraints for merging, clusters the segments resulting from the previous stage, using a context-free similarity measure. This study applied the multistage hierarchical clustering method to the data generated by band reduction, band selection and data compression. The classification results were compared with them using full bands.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.9
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• pp.916-921
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• 2011

Mobile robot localization is the task of estimating the robot pose in a given environment. This research deals with outdoor localization based on an elevation map. Since outdoor environments are large and contain many complex objects, it is difficult to robustly estimate the robot pose. This paper proposes a Hausdorff distance-based map matching method. The Hausdorff distance is exploited to measure the similarity between extracted features obtained from the robot and elevation map. The experiments and simulations show that the proposed Hausdorff distance-based map matching is useful for robust outdoor localization using an elevation map. Also, it can be easily applied to other probabilistic approaches such as a Markov localization method.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.5
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• pp.373-378
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• 2001

The optimization method based on an enhanced genetic algorithms is for multimodal function optimization in this paper. This method is consisted of two main steps. The first step is a global search step using the genetic algorithm(GA) and function assurance criterion(FAC). The belonging of an population to initial solution group is decided according to the FAC. The second step is to decide the similarity between individuals, and to research the optimum solutions by single point method in reconstructive search space. Four numerical examples are also presented in this papers to comparing with conventional methods.

• The KSFM Journal of Fluid Machinery
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• v.8 no.6 s.33
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• pp.26-32
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• 2005

1.6 MW class supersonic partial admission impulse turbine has been designed and tested in Korea Aerospace Research Institute for the liquid rocket engine application. The test has been performed using a high pressure air source facility in KARI. For the turbine power absorption, a hydraulic dynamometer has been used. Appropriate similarity relations are used for the determination of test condition. Various settings of turbine pressure ratio and rotational speed are tested to investigate global turbine characteristics. From measured data, parameters related to the turbine design are derived and validated.

• International Journal of Automotive Technology
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• v.8 no.1
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• pp.83-91
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• 2007

Nowadays, the increasing global competition forces manufacturing enterprises to apply new technologies such as laser welding to manufacturing of their products. In case of automotive industries, they interest in assembly system for BIW (Body in White) carrying out laser welding. In this paper, the method of implementation for digital laser welding assembly system is proposed. Based on the requirements of assembly tasks obtained through product analysis, process modeling is executed by using the IDEF0 and UML model. For digital assembly system, the selected components are modeled by using 3D CAD tools. According to the system configuration strategy, lots of the alternative solutions for the assembly system of welding side panels are generated. Finally, the optimal laser welding system is chosen by the evaluation of the alternative solutions with TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3_1spc
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• pp.558-565
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• 2013

This paper describes a whole-body (human body's) motion generation scheme for an android robot that uses motion capture device and a nonlinear constrained optimization method. Because the captured motion data are based on global coordinates and the actors have different heights and different upper-lower body ratios, the captured motion data cannot be used directly for a humanoid robot. In this paper, we suggest a method for obtaining robot joint angles, which allow the resultant robot motion to be as close as possible to the captured human motion data, by applying a nonlinear constrained optimization method. In addition, the results are animated to demonstrate the similarity of the motions.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.125-131
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• 2004

1.6 MW class supersonic partial admission impulse turbine has been designed and tested in Korea Aerospace Research Institute for the liquid rocket engine application. The test has been performed using a high pressure air source facility in KARI. For the turbine power absorption, a hydraulic dynamometer is used. Appropriate similarity relations are used for the determination of test condition. Various settings of turbine pressure ratio and rotational speed are tested to investigate global turbine characteristics. From measured data, Parameters related to the turbine design are derived and validated.

• Wind and Structures
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• v.2 no.2
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• pp.105-117
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• 1999

The various spectral density functions of wind are applied in the wind process simulation by the spectral representation method. In view of the spectral density functions, the characteristics of the simulated processes are compared. The ensemble spectral density functions constructed from the simulated sample processes are revealed to have the similarity not only in global shape but also in the maximum values with the target spectral density functions with a high accuracy. For the correlation structure to be satisfied in the circumferential direction on the cooling tower shell, a new formula is suggested based on the mathematical expression representing the circumferential distribution of the wind pressure on the cooling tower shell. The simulated wind processes are applied in the dynamic analysis of cooling tower shell in the time domain and the fluctuating stochastic behavior of the cooling tower shell is investigated.