• International Journal of Computer Science & Network Security
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• v.23 no.10
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• pp.81-88
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• 2023

In the present scenario, enormous amounts of data are produced every second. These data also contain private information from sources including media platforms, the banking sector, finance, healthcare, and criminal histories. Data mining is a method for looking through and analyzing massive volumes of data to find usable information. Preserving personal data during data mining has become difficult, thus privacy-preserving data mining (PPDM) is used to do so. Data perturbation is one of the several tactics used by the PPDM data privacy protection mechanism. In Perturbation, datasets are perturbed in order to preserve personal information. Both data accuracy and data privacy are addressed by it. This paper will explore and compare several perturbation strategies that may be used to protect data privacy. For this experiment, two perturbation techniques based on random projection and principal component analysis were used. These techniques include Improved Random Projection Perturbation (IRPP) and Enhanced Principal Component Analysis based Technique (EPCAT). The Naive Bayes classification algorithm is used for data mining approaches. These methods are employed to assess the precision, run time, and accuracy of the experimental results. The best perturbation method in the Nave-Bayes classification is determined to be a random projection-based technique (IRPP) for both the cardiovascular and hypothyroid datasets.

• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.119-128
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• 2012

In this study, experimental vibration tests are performed on a real full-scale railway steel plate girder bridge, which resides in open-space environments. Using experimental modal analysis techniques, the modal parameters of the railway steel plate girder bridge yielded by the modal testing of the impact hammer are compared and investigated with the natural frequencies and mode shapes obtained by finite element analysis. This work focuses on the application of model updating techniques to measured experimental data and output-only data from an analytical vibration study that takes into account various geometric and material properties of the bridge members. A finite element model of the railway bridge structure is used to verify the modal experimental results. It is subsequently updated using the corresponding modal identification technique. The basic database is provided to evaluate damage, which can be determined based on the changes in the element properties, resulting from the process of updating the finite element model benchmark and experimental data.

• Journal of Navigation and Port Research
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• v.26 no.3
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• pp.281-288
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• 2002

It might be true that both experimental and analytic techniques have been developed in the vibration analysis end engineering. It could not be said, however, that the experimental method has been also developed as much as analytic method, such as Finite Element Method One of the reason is that computation time becomes longer and that the solution often diverges depending on the choice of initial value in solving nonlinear equation. The equation in experimental modal analysis is usually composed of the nonlinear term of natural frequency and modal damping ratio, and the linear one of equivalent stiffness. In this study, the nonlinear terms were solved first, and then the linear term was obtained. The experimental modal parameters were estimated, applying the developed experimental modal analysis curve-fitting method to the super-structure model. In addition, the number of modes and modal damping ratio could be easily determined by the developed program with the application of graphical techniques and with easy handling button.

• Journal of the Korean Society of Earth Science Education
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• v.7 no.1
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• pp.34-42
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• 2014

The purpose of this study was to examine the effects on the effects of science lessons using six thinking hats techniques on creativity and science academic achievement. To verify the research problem, the subject of this study was fourth-grade students selected from four classes of an elementary school located in Busan. For ten weeks, the experimental group of 40 students was taught using the six thinking hats techniques. The comparative group also of 40 students, was taught in normal classes which used a Text-book. Children were given a creativity test and academic achievement test in science to measure the effects on six thinking hats techniques. Likert scales were used to gather students feedbacks on creativity and science academic achievement. Through these procedures, the following results were obtained: First, the six thinking hats techniques had a more effect on creativity than the normal classes, where a text-book was used. Second, the six thinking hats techniques could be seen to be effective in improving the student's academic achievements in science than the normal classes which used a Text-book. Third, the result of the student recognition investigation, we could know that the students showed lots of interest in the science lessons using six thinking hats techniques, and they were able to understand the scientific theories. As a result, the elementary science class with six thinking hats techniques had the effects of developing creativity and science academic achievement. It means the science class with six thinking hats techniques has potential possibilities and value to develop creativity and science academic achievement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.328-334
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• 2001

Up to now. vibration analysis and vibration engineering have been developed, encompassing the aspects of both experimental and analytical techniques. Using experimental modal analysis or modal testing, the mode shapes and frequencies of practical structure can be measured accurately. Curve-Fitting Method is realized through experimental modal identification. In the experimental modal parameter estimation, the estimation of modal damping factor is difficult for complicated and large structure. Also numbers of Selected mode are determined before the procedure. This paper describes the vibration shape of the super-structure model of ship through experimental modal analysis.

• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.142-157
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• 2015

This study examines how traditional knowledge functions in the specific techniques to make pottery in terms of the traditional knowledge on the pottery techniques of Onggi potters. It focuses on how traditional pottery manufacturing skills are categorized and what aspects are observed with regard to the techniques. The pottery manufacturing process is divided into the preparation step of raw material, the molding step of pottery, and the final plasticity step. Each step involves unique traditional knowledge. The preparation step mainly comprises the knowledge on different kinds of mud. The knowledge is about the colors and properties of mud, the information on the regional distribution of quality mud, and the techniques to optimize mud for pottery manufacturing. The molding step mainly involves the structure and shape of spinning wheels, the techniques to accumulate mud, ways to use different kinds of tools, the techniques to dry processed pottery. The plasticity step involves the knowledge on kilns and the scheme to build kilns, the skills to stack pottery inside of the kilns, the knowledge on firewood and efficient ways of wood burning, the discrimination of different kinds of fire and the techniques to stoke the kilns. These different kinds of knowledge may be roughly divided into three categories : the preparation of raw material, molding, and plasticity. They are closely connected with one another, which is because it becomes difficult to manufacture quality pottery even with only one incorrect factor. The contents of knowledge involved in the manufacturing process of pottery focused are mainly about raw material, color, shape, distribution aspect, fusion point, durability, physical property, etc, which are all about science. They are rather obtained through the experimental learning process of apprenticeship, not through the official education. It is not easy to categorize the knowledge involved. Most of the knowledge can be understood in the category of ethnoscience. In terms of the UNESCO world heritage of intangible cultural assets, the knowledge is mainly about 'the knowledge on nature and universe'. Unique knowledge and skills are, however, identified in the molding step. They can be referred to 'body techniques', which unify the physical stance of potters, tools they employ, and the conceived pottery. Potters themselves find it difficult to articulate the knowledge. In case stated, it cannot be easily understood without the experience and knowledge on the field. From the preparation of raw material to the complete products, the techniques and traditional knowledge involved in the process of manufacturing pottery are closely connected, employing numerous categories and levels. Such an aspect can be referred to as a 'techniques chain'. Here the techniques mean not only the scientific techniques but also, in addition to the skills, the knowledge of various techniques and levels including habitual, unconscious behaviors of potters.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.93-98
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• 1998

Recently, consumers are tend to purchase the user-centered designed product using interface enginnering and human factors techniques. Therefore, it is important that the designer's requirements should be analyzed focused on the human machine interface. This paper described the interface usability evaluation technique(suvjective evaluation) for the interface between user and product. This methodology is the integrated interface usbility evaluation method AHP and Conjoint Analysis. AHP(Analytic Hierarchy Process) is a multicriteria decision model to give priority after expressing hierarchically for decision making problem. Conjoint Analysis enduavors to unravel the value, or partworths, that consumers place on the product or service's attributes from experimental subjects' evluation of profiles based on hypothetical products or services. A new usability test methodology proposed by this paper includes techniques jointed both consistency test by AHP and experimental subjective evaluation of profiles by Conjoint Analysis for evaluating the user's emotion and impression.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.29-33
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• 2003

The improvement of dimensional accuracy for forged part is one of major goals in cold forging industry. There are many problems in controlling the dimension only by the trial-and-error, especially for a precision forged gear. A FEM analysis has been used in developing the forging technology. However, FE techniques have to be reconfirmed for predicting accurately the dimension of forged part. In this study, the effects of elastic characteristics and temperature changes are investigated by the comparisons between experimental and FEA in cold forging. When FE models related with elastic characteristics are considered as reality, FE results could predict the part dimension within the range of 10 $\mu\textrm{m}$. And if temperature also is considered really, the predicted dimensions are well coincided with the experimental down to about 5$\mu\textrm{m}$.

• Journal of Korean Elementary Science Education
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• v.31 no.2
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• pp.243-252
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• 2012

The purpose of this study was to examine the effect of utilization of creative techniques in elementary science class on science learning motivation and science academic achievement. To verify this study, the subjects of this study were sixth-grade students selected from four classes of an elementary school located in U Metropolitan city. First, the experimental group showed a significant improvement in their science learning motivation compared to the comparative group. Second, the experimental group showed a significant improvement in their science academic achievement compared to the comparative group.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.537-542
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• 2006

This paper deals with the vibration isolation techniques for a large structure using experimental research. In the case of vibration isolation for the vicinity of a subway or a railroad station, most of vibration isolation techniques using isolation materials with high isolation efficiency only, have been applied. Therefore, the quantitative evaluation and design technologies are required for a vibration isolation of large structures. In this study, firstly, vibration characteristics due to train or subway are analyzed. Secondly, the performance of existing vibration isolation materials such as precision isolation material, elastomer is estimated through the experiments. Thirdly the performance of tire isolation material and its frame is tested and evaluated.