• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.134-139
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• 2005

This paper presents a robust design of vehicle interior noise using Taguchi method and a substructure synthesis method with a hybrid model. Firstly, the proposed method identifies the critical process of the concerned interior noise through a TPA (Transfer Path Analysis). Secondly, a strategy for a robust design is discussed, in which the major noise factor among uncertainties in the process is quality distribution of rubber bushes connecting a cradle and a trimmed body. Thirdly, a virtual test model fer the process is developed by applying a substructure synthesis method with a hybrid modeling approach. Fourthly, virtual tests are carried out according to the predefined tables of orthogonal array in Taguchi robust design process. The process was performed under 2 sub-steps. The first step is sensitivity analysis of 31 panels, and the other step is weight optimization of mass dampers on sensitive panels. Finally, two vehicles with the proposed countermeasures were validated. The proposed method reduces 87.5% of trials of measurements due to the orthogonal arrays and increases robustness by 8.6dB of S/N ratio and decreases $5\;dB(A){\sim}10\;dB(A)$ of interior noise in the concerned range of RPM.

• Smart Structures and Systems
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• v.25 no.5
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• pp.559-567
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• 2020

Vibration at the tip of various flexible manipulators may affect their operation accuracy and work efficiency. To suppress such vibrations, the feasibility of using MFC actuators and sensors is investigated in this paper. Considering the convergence of the famous filtered-x least mean square (FXLMS) algorithm could not be guaranteed while it is employed for vibration suppression of plants with varying secondary path, this paper proposes a new multiple model switching adaptive control algorithm to implement the real time active vibration suppression tests with a new multiple switching strategy. The new switching strategy is based on a cost function with reconstructed error signal and disturbance signal instead of the error signal from the error sensor. And from a robustness perspective, a new variable step-size sign algorithm (VSSA) based FXLMS algorithm is proposed to improve the convergence rate. A cantilever beam with varying tip mass is employed as flexible manipulator model. MFC layers are attached on both sides of it as sensors and actuators. A co-simulation platform was built using ADAMS and MATLAB to test the feasibility of the proposed algorithms. And an experimental platform was constructed to verify the effectiveness of MFC actuators and sensors and the real-time vibration control performance. Simulation and experiment results show that the proposed FXLMS algorithm based multiple model adaptive control approach has good convergence performance under varying load conditions for the flexible cantilever beam, and the proposed FX-VSSA-LMS algorithm based multiple model adaptive control algorithm has the best vibration suppression performance.

• The Journal of Society for e-Business Studies
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• v.7 no.1
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• pp.19-34
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• 2002

The main objective of this research is to find out whether there exist any user interface factors that influence service information management professionals(SIMP)'s business activities on the web. The result of this study shows that there exists a significant level of difference between two groups of office Professionals： SIMP and general office management professionals on user interface factors. We analyzed the past and current research results and focused on four major evaluation categories： (1) web design, (2) structure, (3) navigation, and (4) interaction and identified 26 evaluation items in those categories. The study has been initiated by an intuition that there might be a significant difference in sets of user interface factors that influence SIMP and general office professionals. From the list of Best 100 Web Sites the best 30 information-providing web sites and the best 30 service-providing web sites were carefully chosen by a panel of 10 members for each group. To evaluate 60 web sites, another panel was formed by 30 professionals from each group, and they conducted evaluation in their own work settings. Reliability analysis on user interface factors and T-test to find out any influencing factors on SIMP were performed. As a result of this study, we have recognized that clarity, formation, consciseness, economics, and robustness are the most influencing user interface factors for web designers to concern when they develop web sites for SIMP. The study result can be improved by enhancing reliability of choosing target web sites In investigate and panel members. Also, in the future study it is recommended to investigate influencing factors for office professionals in terms of. age, sex, experience, academic background, etc.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.107-112
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• 2016

In this paper, the hydrophobic rough surfaces were prepared by employing a conventional nano-imprint lithography technique, and the effects of surface parameter, ratio of the top surface to the flat unit cell, on the impingement behaviors of liquid droplet were investigated to improve robustness of hydrophobic functionality. The critical height defined for the transition from rebound to fragmentation is measured by droplet impingement test in order to study dynamic behavior of an impinged droplet. It showed the critical height decreased with high surface parameter while it increased with low surface parameter. However, the critical height decreased again as surface parameter decreased further. Observed results suggest that the optimized surface pattern should be designed for the increased critical height.

• Journal of KIISE:Databases
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• v.34 no.2
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• pp.99-108
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• 2007

In this paper, we design and implement the Film Defect Inspection System (FDIS) that detects film defects and determines their types which can be used for producing polarized films of TFT-LCD. The proposed system is designed to detect film defects from polarized film images using image segmentation techniques and to determine defect types through the image analysis of detected defects. To determine defect types, we extract features such as shape and texture of defects, and compare those features with corresponding features of referential images stored in a template database. Experimental results using FDIS show that the proposed system detects all defects of test images effectively (Precision 1.0, Recall 1.0) and efficiently (within 0.64 second in average), and achieves the considerably high correctness in determining defect types (Precision 0.96 and Recall 0.95 in average). In addition, our system shows the high robustness for rotated transformation of images, achieving Precision 0.95 and Recall 0.89 in average.

• Journal of Korea Water Resources Association
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• v.38 no.5 s.154
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• pp.333-343
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• 2005

The upwind model is well known to simulate shockwaves, but it is rarely applied to natural rivers because of problems caused by the source terms. Although several methods have been developed to deal with the source terms, none of them has been applied to natural rivers. This paper deals with application of the upwind model to the natural river. An implicit upwind model is applied to a hypothetical irregular channel and a natural river with highly irregular bed, width, and hydraulic structures. Different types of the flows including steady-state flow, flood wave, dam-break wave, and bore are simulated to test accuracy and applicability of the implicit upwind model. It is proved that the model can simulate various types of flows in natural rivers with high accuracy and robustness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4491-4509
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• 2017

The present paper proposes a novel dynamic system for hand gesture recognition. The approach involved is comprised of three main steps: detection, tracking and recognition. First, the gesture contour captured by a 2D-camera is detected by combining the three-frame difference method and skin-color elliptic boundary model. Then, the trajectory of the hand gesture is extracted via a gesture-tracking algorithm based on an occlusion-direction oriented linear extrapolation predictor, where the gesture coordinate in next frame is predicted by the judgment of current occlusion direction. Finally, to overcome the interference of insignificant trajectory segments, the longest common subsequence (LCS) is employed with the aid of velocity information. Besides, to tackle the subgesture problem, i.e., some gestures may also be a part of others, the most probable gesture category is identified through comparison of the relative LCS length of each gesture, i.e., the proportion between the LCS length and the total length of each template, rather than the length of LCS for each gesture. The gesture dataset for system performance test contains digits ranged from 0 to 9, and experimental results demonstrate the robustness and effectiveness of the proposed approach.

• Journal of Service Research and Studies
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• v.7 no.4
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• pp.1-14
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• 2017

Little empirical consumer research has focused on perceived conspicuous consumption in the respect of negative emotion. This research aims to prove the perceived conspicuous consumption's negative effect on consumers' attitude toward brand. In this research, two experiments were designed to test hypothesis. The results of analysis confirm that perceived conspicuous consumption affects the attitude towards brand, Consumer's temporal power distance belief mediates the relation between perceived conspicuous consumption and brand evaluation, in line with our assumption. The level of perceived group norm towards conspicuous consumption (high vs. low) moderates the relation between perceived conspicuous consumption and brand evaluation. In further research, the group norm scale should be improved and additional experiment adopting variety priming or manipulation method should be conducted for robustness of causality.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.5
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• pp.388-399
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• 2016

A motion analysis of an underwater towed cable is a complex task due to its nonlinear nature of the problem. The major source of the nonlinearity of the underwater cable analysis is that the motion of the cable involves large rigid-body motion. This large rigid-body motion makes difficult to use standard displacement-based finite element method. In this paper, the authors apply recently developed nodal position-based finite element method which can deal with the geometric nonlinearity due to the large rigid-body motion. In order to enhance the stability of the large-scale nonlinear cable motion simulation, an efficient time-integration scheme is proposed, namely predictor/multi-corrector Newmark scheme. Three different predictors are introduced, and the best predictor in terms of stability and robustness for impulsive cable motion analysis is proposed. As a result, the nonlinear motion of underwater cable is predicted in a very efficient manner compared to the classical finite element of finite difference methods. The efficacy of the method is demonstrated with several test cases, involving static and dynamic motion of a single cable element, and also under water towed cable composed of multiple cable elements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7C
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• pp.696-705
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• 2005

The rapid progress of the software has enabled individuals to copy and remake digital contents, which was only done by professionals. However, this rapid growth of software has brought many other defects. As a solution to the problems, contents producer needs to have certification and inspection of its contents text and hold the proprietary rights. In this paper, the new video watermarking scheme is proposed which is appropriate for the requirements mentioned for digital video contents and it is applied to MPEG-2 video encoder and decoder. In order to insert watermark sequence for digital video data, watermarking used blocks reordering algorithm and SCL(secret code list). It is satisfied two properties of cryptography that confidentiality and integrity. We test the proposed algorithm to see its performance in terms of watermark capacity, compression robustness and visual quality impact. According to the experiment of proposed watermarking algorithm, we obtained satisfactory results that watermark can still be extracted after MPEG-2 re-encoding at lower bit rates. It is important property for data hiding and user authentication in video data.