• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.107-112
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• 1998

A great deal of time and effort are required to evaluate the safety and durability of a vehicle structure in the vehicle development stage. It is difficult to find the reasons for cracks which occur in the body and frame of a vehicle during tests. Recently computer aided engineering techniques have been utilized to solve the problems of safety and durability of vehicles. In this study, a dynamic stress analysis is performed on the frame of the vehicle by rigid and flexible multibody dynamics techniques. The result of the analysis is compared to that of the actual test. The full vehicle dynamic models for the rigid and flexible bodies are developed by DADS package. The modal coordinate system is used to save time for the dynamic stress analysis. The flexible multibody dynamic models have 12 normal modes considering the flexibility of the frame. Dynamic stresses arc calculated by relating the stress influence coefficients and the applied forces.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.13-19
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• 2003

Discriminant method using seismic signal was studied for discrimination of surface explosion. By means of the seismic spectral characteristics, multi-variate discriminant analysis was performed. Four single discriminant techniques - Pg/Lg, Lg1/Lg2, Pg1/Pg2, and Rg/Lg - based on seismic source theory were applied to explosion and earthquake training data sets. The Pg/Lg discriminant technique was most effective among the four techniques. Nevertheless, it could not perfectly discriminate the samples of the training data sets. In this study, a compound linear discriminant analysis was defined by using common characteristics of the training data sets for the single discriminants. The compound linear discriminant analysis was used for the single discriminant as an independent variable. From this analysis, all the samples of the training data sets were correctly discriminated, and the probability of misclassification was lowered to 0.7％.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.155-162
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• 2021

The expansion of the world wide web has led to a huge amount of user generated content over different forums and social media platforms, these rich data resources offer the opportunity to reflect, and track changing public sentiments and help to develop proactive reactions strategies for decision and policy makers. Analysis of public emotions and opinions towards events and sentimental trends can help to address unforeseen areas of public concerns. The need of developing systems to analyze these sentiments and the topics behind them has emerged tremendously. While most existing works reported in the literature have been carried out in English, this paper, in contrast, aims to review recent research works in Arabic language in the field of thematic sentiment analysis and which techniques they have utilized to accomplish this task. The findings show that the prevailing techniques in Arabic topic-based sentiment analysis are based on traditional approaches and machine learning methods. In addition, it has been found that considerably limited recent studies have utilized deep learning approaches to build high performance models.

• Smart Structures and Systems
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• v.22 no.6
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• pp.711-725
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• 2018

Most of the practical engineering structures exhibit nonlinearity due to nonlinear dynamic characteristics of structural joints, nonlinear boundary conditions and nonlinear material properties. Hence, it is highly desirable to detect and characterize the nonlinearity present in the system in order to assess the true behaviour of the structural system. Further, these identified nonlinear features can be effectively used for damage diagnosis during structural health monitoring. In this paper, we focus on the detection of the nonlinearity present in the system by confining our discussion to only a few selective time-frequency analysis and multivariate analysis based techniques. Both damage induced nonlinearity and inherent structural nonlinearity in healthy systems are considered. The strengths and weakness of various techniques for nonlinear detection are investigated through numerically simulated two different classes of nonlinear problems. These numerical results are complemented with the experimental data to demonstrate its suitability to the practical problems.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.463-478
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• 2019

The most important non-functional requirements for dependability of any Embedded Real-Time Safety Systems are safety, availability and reliability requirements. System architecture plays the primary role in achieving these requirements. Compliance with these non-functional requirements should be ensured early in the development cycle with appropriate considerations during architectural design. In this paper, we present an application of system architecture modeling for quantitative assessment of system dependability. We use probabilistic model checker (PRISM), for dependability analysis of the DTMC model derived from system architecture model. In general, the model checking techniques do not scale well for analyzing large systems, because of prohibitively large state space. It limits the use of model checking techniques in analyzing the systems of practical interest. We propose abstraction based compositional analysis methodology to circumvent this limitation. The effectiveness of the proposed methodology has been demonstrated using the case study involving the dependability analysis of safety system of a large Pressurized Water Reactor (PWR).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.863-868
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• 2002

Operational Modal Analysis also known as Ambient Modal Analysis has an increasing interest in mechanical engineering. Especially on big structures where the excitation and not less important the determination of the forces is most often a problem. In a structure like a wind turbine wing where the modes occur both close in frequency and hi-directional the ambient excitation has big advantages. In this paper modal parameters are identified from the wing by operational modal analysis. For the parameter identification both parametric and non-parametric techniques are used. Advantages and disadvantages are discussed and results from the different techniques are compared

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.24-31
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• 2023

The purpose of this paper is to divide franchise education and restaurant education programs into three factors: educational content, educational techniques, and educational environment. After completing the franchise curriculum, we will identify what educational programs affect corporate performance and CEO's capabilities. A total of 99 copies were used as statistical analysis data by conducting a survey of those who completed the training from May 01 to May 15, 2023. The survey used the Likert 5-point scale, and for data analysis, hypothesis verification was conducted using frequency analysis, demographic analysis, and reliability analysis using SPSS23. As a result, it was confirmed that all three factors of franchise education are factors that affect performance and competency. Therefore, among franchise education programs, it is necessary to be faithful to the contents of education, use appropriate educational techniques, and prepare an educational environment well.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.44-50
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• 2024

This paper offers an overview of matrix formation and calculation techniques within the framework of General Linear Models (GLMs). It takes a sequential approach, beginning with a detailed exploration of matrix formation and calculation methods in regression analysis and univariate analysis of variance (ANOVA). Subsequently, it extends the discussion to cover multivariate analysis of variance (MANOVA). The primary objective of this study was to provide a clear and accessible explanation of the underlying matrices that play a crucial role in GLMs. Through linking, essentially different statistical methods, by fundamental principles and algebraic foundations that underpin the GLM estimation. Insights presented here aim to assist researchers, statisticians, and data analysts in enhancing their understanding of GLMs and their practical implementation in diverse research domains. This paper contributes to a better comprehension of the matrix-based techniques that can be extended to GLMs.

• Explosives and Blasting
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• v.40 no.1
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• pp.1-16
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• 2022

In order to develop effective and safe blasting techniques or to introduce foreign advanced blasting techniques to domestic industry, the analysis of research trend in blasting field in the world is essential. In generally, such a research trend analysis was carried out for limited number of published papers. In this study, a bibliometric analysis was performed using VOSviewer for the overall papers published in international journals to figure out the variation of research trend in blasting area. From the keyword analysis, it was found that the number of published papers and the number of overall keywords was limited in the 2000s. Since 2010, the number of published papers was increased rapidly and the keywords were diversified with the introduction of artificial intelligence(AI). The keyword analysis for 2017~2021 showed that various hybrid AI techniques were actively applied in the evaluation of blasting effect.

• Journal of the Korean Society of Costume
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• v.60 no.2
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• pp.68-80
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• 2010

In order to get the information needed for the preservation and application of Korean traditional dyeing techniques to modern textiles products, the present study analyzed the color and color differences of dyed goods according to the contents of fabrics and the traditional techniques of dyeing the Buddhist priests' robes. A spectrophotometer was used to measure the differences in achromatic color according to dyeing techniques, dyestuff, kinds of dyed fabrics, and after-treatment methods. Through experiments based on the traditional dyeing techniques used by Korean Buddhist priests, a total of 144 pieces of dyed fabrics were made and all the colors of those 144 pieces were analyzed. Among three dyeing techniques tested; (1) dyeing with a dye-bath made of ink stick that was ground down with water, (2) dyeing with a dye-bath made by shaking a bag containing ink powder in water, and (3) dyeing with a dye-bath made by rubbing a boiled ink stick on a fabric, dyeing with a dye-bath made of ink stick that was ground down with water was shown to be the best technique in terms of coloring. For fabrics, ramie was the best of all three techniques in terms of making achromatic color. Starching and rubbing was the most effective after-treatment method used on both fabrics dyed with a grounded ink stick and on fabrics dyed by rubbing a boiled ink stick on them. As a whole, yangyeonmook, made from minerals' soot, is better than songyeonmook, which is made by burning old pine trees or yooyeonmook, which is made by burning oils from seeds. Therefore, yangyeonmook could help to preserve and utilize the traditional dyeing techniques of Korea in a practical way in modern life.