• Journal of Engineering Education Research
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• v.19 no.2
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• pp.60-69
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• 2016

This paper deals with the selection method of effective engineering design problem based on LEGO Mindstorm NXT for basic design education. By YouTube case study of various LEGO-based engineering designs for olympic sports, performance criteria have been developed including programming complexity, structural complexity, sensor/actuator complexity and variety of game operation. Programming complexity includes range of programming code length and possible program variety. Structural complexity includes variety of structural elements such as length, shape, weight, and volume to overcome design restrictions. Sensor/actuator complexity includes variety of sensor used and number of possible actuator assemblies. Variety of game operation includes game complexity and required creativity to make LEGO robots. Based on these performance criteria, four representative sports were selected as the candidates for effective engineering design problem. Finally, feasibility and attributes of each candidate were verified by real implementation examples.

• Journal of the Korean Society of Systems Engineering
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• v.13 no.2
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• pp.49-56
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• 2017

Implementation of Model-based Systems Engineering(MBSE) depends on a model supporting efficient communication among engineers from various domains. And SysML is designed to create models supporting MBSE but unfortunately, SysML itself is not practical enough to be used in real-world engineering projects. SysML is designed to express generic systems and requires specialized knowledge, so a model written in SysML is less capable of supporting communication between a systems engineer and a sub-system engineer. Domain Specific Languages(DSL) can be a great solution to overcome the weakness of the standard SysML. A SysML based DSL means a customized SysML for a specific engineering domain. Unfortunately, current researches on SysML Domain Specific Language(DSL) for the plant engineering industry are still on the early stage. So as the first step, we have developed our own SysML based Piping & Instrumentation Diagram (P&ID) creation environment and P&ID itself of a specific plant system, using a widely used SysML authoring tool called MagicDraw. P&ID is one of the most critical output during the plant design phase, which contains all information required for the plant construction phase. So a SysML based P&ID has a great potential to enhance the communication among plant engineers of various disciplines.

• Steel and Composite Structures
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• v.42 no.5
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• pp.685-697
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• 2022

In this paper, a vibration-based method using the change ratios of modal data and the experience-based learning algorithm is presented for quantifying the position, size, and interface layer of delamination in laminated composites. Three types of objective functions are examined and compared, including the ones using frequency changes only, mode shape changes only, and their combination. A fine three-dimensional FE model with constraint equations is utilized to extract modal data. A series of numerical experiments is carried out on an eight-layer quasi-isotropic symmetric (0/-45/45/90)s composited beam for investigating the influence of the objective function, the number of modal data, the noise level, and the optimization algorithms. Numerical results confirm that the frequency-and-mode-shape-changes-based technique yields excellent results in all the three delamination variables of the composites and the addition of mode shape information greatly improves the accuracy of interface layer prediction. Moreover, the EBL outperforms the other three state-of-the-art optimization algorithms for vibration-based delamination detection of composites. A laboratory test on six CFRP beams validates the frequency-and-mode-shape-changes-based technique and confirms again its superiority for delamination detection of composites.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.225-234
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• 2020

Reliability-based structural optimization usually requires designers or engineers model different designs manually, which is considered very time consuming and all possibilities cannot be fully explored. Otherwise, a lot of time are needed for designers or engineers to learn mathematical modeling and programming skills. Therefore, a framework that integrates generative design, structural simulation and reliability theory is proposed. With the proposed framework, various designs are generated based on a set of rules and parameters defined based on visual programming, and their structural performance are simulated by OpenSees. Then, reliability of each design is evaluated based on the simulation results, and an optimal design can be found. The proposed framework and prototype are tested in the optimization of a steel frame structure, and results illustrate that generative design based on visual programming is user friendly and different design possibilities can be explored in an efficient way. It is also reported that structural reliability can be assessed in an automatic way by integrating Dynamo and OpenSees. This research contributes to the body of knowledge by providing a novel framework for automatic reliability evaluation and structural optimization.

• Journal of information and communication convergence engineering
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• v.1 no.4
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• pp.209-212
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• 2003

In this paper, we proposed new speech feature parameter through parts-based feature extraction of speech spectrum using Non-Negative Matrix Factorization (NMF). NMF can effectively reduce dimension for multi-dimensional data through matrix factorization under the non-negativity constraints, and dimensionally reduced data should be presented parts-based features of input data. For speech feature extraction, we applied Mel-scaled filter bank outputs to inputs of NMF, than used outputs of NMF for inputs of speech recognizer. From recognition experiment result, we could confirm that proposed feature parameter is superior in recognition performance than mel frequency cepstral coefficient (MFCC) that is used generally.

• Journal of the Korean Society for Railway
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• v.6 no.1
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• pp.1-9
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• 2003

This article proposes an integrated systems engineering and safety analysis model for safety-critical systems development. A methodology in system design for safety is considered during the early phase of the development life cycle of systems engineering process. The evolution of the design automation technology has enabled engineers to perform the model-based systems engineering. A Computer-Aided Systems Engineering(CASE) tool, CORE, is utilized to integrate the systems engineering model with a system safety analysis model. The results of the functional analysis phase can drive the analysis of the system safety. An example of Communications-Based Train Control(CBTC) system for an Automated Guided Transit(AGT) system demonstrated an application of the integrated model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1441-1447
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• 2014

A robust new algorithm for R wave detection named for Multiscale-based Peak Detection(MSPD) is assessed in this paper using MIT/BIH Arrhythmia Database. MSPD algorithm is based on a matrix composed of local maximum and find R peaks using result of standard deviation in the matrix. Furthermore, By reducing needless procedure of proposed algorithm, improve algorithm ability to detect R peak efficiently. And algorithm performance is assessed according to detection rates about various arrhythmia database.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.209-212
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• 2011

Selection of finishing materials in the design stage is an important management factor in terms of use safety and satisfaction, and work cost and process. However, selection of materials in the design stage is usually conducted without related guidelines or a set process, but depends on the experience of the architect or advice of materials company employees. Therefore, the aim of this study was to develop a finishing materials selection process that can be used by a architect. Materials selection related rules collected through interview with experts and five office building cases were used as knowledge. In addition, another aim of the study was to propose a prototype system interface for use in the field.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.411-416
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• 2002

This paper is concerned with the development of web-based engineering calculation program using Javascript. Recently, various techniques are developed based on the advance of the internet environment. The Javascript can be used in the client PC without any interpreter which is necessary in Java. Simple formula can be easily constructed using the Javascript and the results can be readily available without any playing. In this study, we demonstrated the method of constructing engineering web useful for engineers.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1571-1574
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• 2004