• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.412-422
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• 1999

Scale defects generated on the strip surface in a tandem finishing mill line are collected from the strip trapped among the production mills by freezing the growing scale on the strip by the melt glass coating and shutting down the line simultaneously. The samples observed of its cross sectional figure showed the process of scale defect formation where the defects are formed at the base metal surface by thicker oxidized scale during each rolling passes. The properties of the oxidized layer growth both at rolling and inter-rolling are detected down sized rolling test simulating carefully the rolling condition of the production line. The thickness of the oxidized layer at each rolling pass are simulated numerically. The critical scale thickness to avoid the defect formation is determined through the expression of mutual relation between oxidized layer thickness and the lanks of the strip called quality for the scale defects. The scale growth of scale less than the critical thickness and also to keep the bulk temperature tuning the water flow rate and cooling time appropriately. Two units of Inerstand Cooler are designed and settled among the first three stands in the production line. Two units of scale defect is counted from the recoiled strip and the results showed distinct decrease of the defects comparing to the conventionaly rolled products.

• Journal of Ocean Engineering and Technology
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• v.18 no.5
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• pp.29-35
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• 2004

A new approach, referred to as a successive zooming genetic algorithm (SZGA), is proposed for identifying a global solution, using continuous zooming factors for optimization problems. In order to improve the local fine-tuning of the GA, we introduced a new method whereby the search space is zoomed around the design variable with the best fitness per 100 generation, resulting in an improvement of the convergence. Furthermore, the reliability of the optimized solution is determined based on the theory of probability, and the parameter used for the successive zooming method is optimized. With parameter optimization, we can eliminate the time allocated for deciding parameters used in SZGA. To demonstrate the superiority of the proposed theory, we tested for the minimization of a multiple function, as well as simple functions. After testing, we applied the parameter optimization to a truss problem and wicket gate servomotor optimization. Then, the proposed algorithm identifies a more exact optimum value than the standard genetic algorithm.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.80-89
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• 2011

While detecting changes in XML documents has emerged as a major research area, the level of research on edit scripts, which are the result of the change detection, is not far from satisfactory. In this paper, we present X-treeESgen, the algorithm generating edit scripts used in X-treeDiff+, a change detection algorithm for XML documents. X-treeESgen shows the time complexity of O(n), and support move and copy operations in addition to the basic set that is update, insert, and delete operations. Note that no other change detection algorithm provide all the operations. Also, since the process of generating edit scripts in X-treeESgen is designed independent of the process of matching, various tuning techniques may be applied.

• Convergence Security Journal
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• v.6 no.2
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• pp.31-42
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• 2006

In this paper, we proposed an integrated infrastructure for optimal information security to resolve these kinds of problems and to implement more powerful protection. The proposed infrastructure presents a security framework, provides a functional mechanism, and implements a scheme for information security based on the design concept of integrated structures. In order to ensure effective malicious traffic blocking, this paper emphasizes that a comprehensive approach through infrastructure improvement and combination of scanning tool is the only measure for preparing against today's environment of virus infiltration. The proposed model is a measure developed at a time when a permanent technological solution to virus is yet to be developed. A performance analysis model is developed and the performance is evaluated through the case studies for the proposed methodology. The effectiveness of the infrastructure for optimal information security needs the continuous diagnostic evaluation and tuning through the users or the organizations.

• Structural Engineering and Mechanics
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• v.30 no.2
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• pp.135-146
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• 2008

This study utilizes the fine-tuning and small-digit characteristics of the successive zooming genetic algorithm (SZGA) to propose a method of structural damage detection in a continuum structure, where the differences in the natural frequencies of a structure obtained by experiment and FEM are compared and minimized using an assumed location and extent of structural damage. The final methodology applied to the structural damage detection is a kind of pseudo-discrete-variable-algorithm that counts the soundness variables as one (perfectly sound) if they are above a certain standard, such as 0.99. This methodology is based on the fact that most well-designed structures exhibit failures at some critical point due to manufacturing error, while the remaining region is free of damage. Thus, damage of 1% (depending on the given standard) or less can be neglected, and the search concentrated on finding more serious failures. It is shown that the proposed method can find out the exact structural damage of the monitored structure and reduce the time and amount of computation.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.8
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• pp.1299-1312
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• 2004

This paper suggests the simple form of a fuzzy PID controller and describes the design principle, tracking performance, stability analysis and changes of parameters of a suggested fuzzy PID controller. A fuzzy PID controller is derived from the design procedure of fuzzy control. It is well known that a fuzzy PID controller has a simple structure of the conventional PID controller but posses its self-tuning control capability and the gains of a fuzzy PID controller become nonlinear functions of the inputs. Nonlinear calculation during fuzzification, defuzzification and the fuzzy inference require more time in computation. To increase the applicability of a fuzzy PID controller to digital computer, a simple form of a fuzzy PID controller is introduced by the backward difference mapping and the analysis of the fuzzy input space. To guarantee the BIBO stability of a suggested fuzzy PID controller, ‘small gain theorem’ which proves the BIBO stability of a fuzzy PI and a fuzzy PD controller is used. After a detailed stability analysis using ‘small gain theorem’, from which a simple and practical method to decide the parameters of a fuzzy PID controller is derived. Through the computer simulations for the linear and nonlinear plants, the performance of a suggested fuzzy PID controller will be assured and the variation of the gains of a fuzzy PID controller will be investigated.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.11-15
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• 2000

Speaker adaptive continuous speech recognition for the RM speech corpus is described in this paper. Learning of hidden markov models for the reference speaker is performed for the training data of RM corpus. For the evaluation, evaluation data of RM corpus are used. Parts of another training data of RM corpus are used for the speaker adaptation. After dynamic time warping of another speaker's data for the reference data is accomplished, error back propagation neural network is used to transform the spectrum between speakers to be recognized and reference speaker. Experimental results to get the best adaptation by tuning the neural network are described. The recognition ratio after adaptation is substantially increased 2.1 times for the word recognition and 4.7 times for the word accuracy for the best.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.404-407
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• 2009

Bluetooth Video Distribution Profile (VDP) defines the protocol and procedures that realize the distribution of video content compressed in a specific format for the efficient use of the limited bandwidth. In this paper, we describe the design of VDP tester based on TTCN-2 (Tree and Tabular Combined Notation), a language standardized by ISO for the specification of tests for real-time and communicating systems. Our work was carried out as a part of supporting a new profile testing module for VDP in PTS (Profile Tuning Suite), a reference test system for Bluetooth interoperability testing. Test demonstration for the interoperability with various VDP solutions at the PTS session in UPF30 (Unplug Fest) showed the validity of the developed tester. Eventually, we introduce the PTS architecture, and show the design and implementation of VDP tester included in the released PTS 3.0 in this paper.

• Communications for Statistical Applications and Methods
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• v.27 no.5
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• pp.535-546
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• 2020

In genetic association studies, pleiotropy is a phenomenon where a variant or a genetic region affects multiple traits or diseases. There have been many studies identifying cross-phenotype genetic associations. But, most of statistical approaches for detection of pleiotropy are based on individual tests where a single variant association with multiple traits is tested one at a time. These approaches fail to account for relations among correlated variants. Recently, multivariate regularization methods have been proposed to detect pleiotropy in analysis of high-dimensional genomic data. However, they suffer a problem of tuning parameter selection, which often results in either too many false positives or too small true positives. In this article, we applied selection probability to multivariate regularization methods in order to identify pleiotropic variants associated with multiple phenotypes. Selection probability was applied to individual elastic-net, unified elastic-net and multi-response elastic-net regularization methods. In simulation studies, selection performance of three multivariate regularization methods was evaluated when the total number of phenotypes, the number of phenotypes associated with a variant, and correlations among phenotypes are different. We also applied the regularization methods to a wild bean dataset consisting of 169,028 variants and 17 phenotypes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.529-533
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• 1996

Recently, manufacturing industries are doing their best to increase productivity and to reduce production time. One of tile efforts is to develop user-friendly and effective CAM systems. For this purpose, a CAM system for turning was developed. In the developed system. user interacts with tile CAM system using graphical user interface (GUI) and manufacturing support functions to make NC programs effectively. Manufacturing support functions include cycle decoder. interference check be ween tool and workpicce. bar turning without air cut and dynamic/wireframe simulation. In the cycle decoder. basic options are provided to novices for their convenience. and advanced options are provided to help expert to modify the program using their knowledge. Interference check has been nil issue in tile CAM system for tuning. In this paper. when a user selects a tool. interference check between selected tools and workpieces is done automatically. Moreover. remaining shapes are calculated automatically. Then, tile CAM system requests user to input all additional tool and generates NC codes to cut tile remaining shapes. In bar turning of forged raw material, air cut should be prevented for effective machining. For this purpose, a new algorithm for bar turning was developed. Dynamic and wireframe simulation was used to verify the generated NC code.