• Journal of the Society of Naval Architects of Korea
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• v.50 no.4
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• pp.232-239
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• 2013

This paper provides the structure of a Reynolds Averaged Navier-Stokes(RANS) based simulation method and its validation results for the ship motion problem. The motion information of the hull computed from the equations of motion is considered in the momentum equations as the relative fluid motions with respect to a non-inertial coordinates system. A finite volume method is used to solve the governing equations, while the free surface is captured by using a two-phase level-set method and the realizable k-${\varepsilon}$ model is used for turbulence closure. For the validation of the present numerical approach, the numerical results of the resistance and motion tests for DTMB 5415 at two ship speeds are compared against available experimental data.

• The Journal of the Acoustical Society of Korea
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• v.18 no.3E
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• pp.3-8
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• 1999

In speech recognition for real-world applications, the performance degradation due to the mismatch introduced between training and testing environments should be overcome. In this paper, to reduce this mismatch, we provide a hybrid method of spectral subtraction and residual noise masking. We also employ multiple model approach to obtain improved robustness over various noise environments. In this approach, multiple model sets are made according to several noise masking levels and then a model set appropriate for the estimated noise level is selected automatically in recognition phase. According to speaker independent isolated word recognition experiments in car noise environments, the proposed method using model sets with only two masking levels reduced average word error rate by 60% in comparison with spectral subtraction method.

• Computers and Concrete
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• v.12 no.2
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• pp.229-241
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• 2013

The objective of this study is to reveal the sufficiency of neural networks (NN) as a securer, quicker, more robust and reliable method to be used in seismic assessment of existing reinforced concrete buildings. The NN based approach is applied as an alternative method to determine the seismic performance of each existing RC buildings, in terms of damage level. In the application of the NN, a multilayer perceptron (MLP) with a back-propagation (BP) algorithm is employed using a scaled conjugate gradient. NN based model wasd eveloped, trained and tested through a based MATLAB program. The database of this model was developed by using a statistical procedure called P25 method. The NN based model was also proved by verification set constituting of real existing RC buildings exposed to 2003 Bingol earthquake. It is demonstrated that the NN based approach is highly successful and can be used as an alternative method to determine the seismic performance of each existing RC buildings.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1245-1248
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• 1996

This paper describes a cell programming environment that deals with problems associated with programming Flexible Manufacturing Cells(FMCs). The environment consists of the cell programming editor and the automatic generation module. In the cell programming editor, cell programmers can develop cell programs using task level description set which supports task-oriented specifications for manipulation cell activities. This approach to cell programming reduces the amount of details that cell programmers need to consider and allows them to concentrate on the most important aspects of the task at hand. The automatic generation module is used to transform task specifications into executable programs used by cell constituents. This module is based on efficient algorithm and expert systems which can be used for optimal path planning of robot operations and optimal machining parameters of machine tool operations. The development tool in designing the environment is an object-oriented approach which provides a simple to use and intuitive user interface, and allows for an easy development of object models associated with the environment.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.601-607
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• 2010

For commercial success of emerging service robots, the fault tolerant technology for system reliability and human safety is crucial. Traditionally fault tolerance methods have been implemented in application level. However, from our studies on the common design patterns in fault tolerance, we argue that a framework-based approach provides many benefits in providing reliability for system development. To demonstrate the benefits, we build a framework-based fault tolerant engine for OPRoS (Open Platform for Robotic Services) standards. The fault manager in framework provides a set of fault tolerant measures of detection, isolation, and recovery. The system integrators choose the appropriate fault handling tools by declaring XML configuration descriptors, considering the constraints of components and operating environment. By building a fault tolerant navigation application from the non-faulttolerant components, we demonstrate the usability and benefits of the proposed framework-based approach.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.124-127
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• 2006

IEC 60300 is an advanced Dependability Management System(DMS) designed for highly qualified company. ISO/TS 16949 is an Quality Management System enforced reliability activities. It is now hot issue how to set up and implement DMS. This paper presents an approach for implementing Dependability Management System(IEC 60300) based on Quality Management System(ISO/TS16949). We analyse the difference and relationship between these two systems, and suggest an quantitative method for evaluating DMS by introducing MIR(Maturity Index for Reliability). Finally we analyse the level of reliability activities in these systems by MIR.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1557-1564
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• 2017

We take genomic sequences of high-dimensional low sample size (HDLSS) without ordering of response categories into account. When constructing an appropriate test statistics in this model, the classical multivariate analysis of variance (MANOVA) approach might not be useful owing to very large number of parameters and very small sample size. For these reasons, we present a pseudo marginal model based upon the Gini-Simpson index estimated via Bayesian approach. In view of small sample size, we consider the permutation distribution by every possible n! (equally likely) permutation of the joined sample observations across G groups of (sizes $n_1,{\ldots}n_G$). We simulate data and apply false discovery rate (FDR) and positive false discovery rate (pFDR) with associated proposed test statistics to the data. And we also analyze real SARS data and compute FDR and pFDR. FDR and pFDR procedure along with the associated test statistics for each gene control the FDR and pFDR respectively at any level ${\alpha}$ for the set of p-values by using the exact conditional permutation theory.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.4
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• pp.170-178
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• 2004

As quality becomes a primary leading factor of organizational success, various management strategies have been introduced to improve quality competitiveness. Quality competitiveness, however, is difficult to measure and numerous organizations are struggling to set realistic improvement objectives. The primary purpose of this research is to propose a systematic approach to help the practitioners develop an improvement plan for their organizational quality competitiveness. This approach employs DEA(Data Envelopment Analysis) to evaluate relative efficiency among companies which make efforts to improve their quality competitiveness. It presents an integer programming model to elicit an optimal improvement plan for meeting a target level. A decision support system is also developed for the managers to plan a sequential improvement plan based on both DEA model and the integer programming model.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.1205-1216
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• 2012

The Korea government has recently announced that secure coding is going to be required when building e-government systems. As its initial effort to enhance the security level of e-government applications, it should be highly valued. In its implementation, however, there are some problematic areas or issues that are expected and need to be supplemented. In this regards, we attempt to analyze the Secure Coding Initiatives and derive some problems using an ecosystem approach. Furthermore, a set of institutional suggestions are made in an effort to get over the problems.

• International Journal of Contents
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• v.16 no.4
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• pp.26-38
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• 2020

Determining the optimal levels of the technical attributes (TAs) of a product to achieve a high level of customer satisfaction is the main activity in the planning process for quality function deployment (QFD). In real applications, the number of customer requirements for developing a single product is quite large, and the number of converted TAs is also high so the size of the house of quality (HoQ) becomes huge. Furthermore, the TA levels are often discrete instead of continuous and the product market can be divided into several market segments corresponding to the number of HoQ, which also unacceptably increases the size of the QFD optimization problem and the time spent on making decisions. This paper proposed a genetic algorithm (GA) solution approach to finding the optimum set of TAs in QFD in the above situation. A numerical example is provided for illustrating the proposed approach. To assess the computational performance of the GA, tests were performed on problems of various sizes using a fractional factorial design.