• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.214-220
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• 2023

In this paper, we propose a method to improve texture recognition performance from haptic acceleration signals representing the texture characteristics of object surface materials by using a Conformer model that combines the advantages of a convolutional neural network and a transformer. In the proposed method, three-axis acceleration signals generated by impact sound and vibration are combined into one-dimensional acceleration data while a person contacts the surface of the object materials using a tool such as a stylus , and the logarithmic Mel-spectrogram is extracted from the haptic acceleration signal similar to the audio signal. Then, Conformer is applied to the extracted the logarithmic Mel-spectrogram to learn main local and global frequency features in recognizing the texture of various object materials. Experiments on the Lehrstuhl für Medientechnik (LMT) haptic texture dataset consisting of 60 materials to evaluate the performance of the proposed model showed that the proposed method can effectively recognize the texture of the object surface material better than the existing methods.

• Interaction and multiscale mechanics
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• v.1 no.1
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• pp.83-101
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• 2008

A derivation is given of two-scale models that are able to describe deformation and flow in a fluid-saturated and progressively fracturing porous medium. From the micromechanics of the flow in the cavity, identities are derived that couple the local momentum and the mass balances to the governing equations for a fluid-saturated porous medium, which are assumed to hold on the macroscopic scale. By exploiting the partition-of-unity property of the finite element shape functions, the position and direction of the fractures are independent from the underlying discretization. The finite element equations are derived for this two-scale approach and integrated over time. The resulting discrete equations are nonlinear due to the cohesive crack model and the nonlinearity of the coupling terms. A consistent linearization is given for use within a Newton-Raphson iterative procedure. Finally, examples are given to show the versatility and the efficiency of the approach.

• Computers and Concrete
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• v.18 no.3
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• pp.421-439
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• 2016

Corrosion of embedded reinforcing bars is recognized as being the major cause of deterioration of reinforced concrete structures. With regard to maintenance strategies of concrete nuclear structures, the monitoring of cracking remains of primary importance. Recently, authors have developed a post-treatment technique to extract crack features from continuous computations. In this paper, such technique is applied to carry out a numerical analysis of an accelerated corrosion test. Obtained results allow highlighting specific propagation and failure mechanisms that characterize corrosion-induced cracking.

• The Mathematical Education
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• v.48 no.1
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• pp.93-105
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• 2009

Considering the fact that PCK(pedogogical content knowledge) tends to guarantee the identity of mathematics education as a discipline and the teacher professionalism, PCK is one of the core concepts in the research on subject matter education. The purpose of this study is to review domestic and international researches on the definition and the components of PCK in mathematics. Based on the review, this study identified 3 knowledges which consist PCK; knowedge of mathematic content, knowledge of learner's understanding, and knowledge of teaching. Then this study provided some examples of PKC in the topic, the limit of sequences, and introduced the LMT and TEDS-M items, which were designed to measure the teacher's PCK. Lastly, this study attempted to evaluate the items on mathematics education included in the Teacher Employment Test administered for pre-service/. teachers in Korea based on PCK.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.36.1-36.1
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• 2010

The Redshift Search Receiver (RSR) is a sensitive, ultra-wideband spectrometer that is being built at the University of Massachusetts as one of the facility instruments for the 50-m Large Millimeter Telescope (LMT). It consists of four receivers each covering the entire 3 mm window from 74 to 111 GHz instantaneously. The primary goal of the receiver is to detect multiple molecular lines in galaxies at any distance and uniquely determine the redshift, in particular dust-obscured star forming systems at high-z which are not easily accessible. I will present some results from commissioning of the RSR on the Five College Radio Astronomy Observatory 14-m telescope, and discuss the future of the receiver.

• Korean Journal of Computational Design and Engineering
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• v.10 no.5
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• pp.328-338
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• 2005

CAD systems are routinely used by designers for creating part geometries. Interfaces to CAE/CAM systems are also commonplace enabling the FEA-based design optimization and the rapid fabrication of the designed part. However, conventional CAD systems have thus far focused on objects with homogeneous interior. Two recent advances--use of heterogeneous objects such as Functionally Graded Materials (FGM) in parts and Layered Manufacturing Technology (LMT)--have brought to the forefront the need for CAD systems to support the creation of geometry as well as the graded material inside. We first describe the need and the components of such a CAD system for heterogeneous objects. A prototype CAD system is then described with one specific example (thermal barrier type FGM, pressure vessel) in order to illustrate the use of the implemented CAD system. The implemented system is manually integrated with FEA tools for optimal design. Our ongoing work involves the automation of the integration with FEA tools.

• The Korean Journal of Food And Nutrition
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• v.12 no.1
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• pp.33-38
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• 1999

This study was conducted to investigate the synergic effect of dietary selenium and methionine levels on hepatic lipid metabolism in ethanol treated rats. Sprague-Dawley male rats were fed diets containing three levels of methionine(0,3 and 9g/kg diet) with or without selenium(0.45mg/kg diet). Ethanol was administered with 25%(v/v) ethanol orally at the same time once a day in ethanol group and isocalori sucrose was administered to the control group. The rate were sacrificed after 5 and 10 weeks of feeding period. Glutathione content was decreased by ethanol treatment and significantly increased in proportion to level of dietary methionine and was higher in selenium deficiency group than that of selenium admin-istration group. Lipid peroxide content was significantly increased in deficiency of both methionine and selenium(LMet-Se+EtOH) group. Total lipid triglyceride and cholesteol contents in liver were increas-ed and phospholipid content was decreased in ethanol treated group and ethanol treatment accelerated those increment and decrement in methionine deficiency(LMt) group and excessive methionine admin-istration(HMet)group.

• International Journal of Computer Science & Network Security
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• v.21 no.7
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• pp.56-62
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• 2021

The surge in generic attacks execution against cipher text on the computer network has led to the continuous advancement of the mechanisms to protect information integrity and confidentiality. The implementation of explicit decision tree machine learning algorithm is reported to accurately classifier generic attacks better than some multi-classification algorithms as the multi-classification method suffers from detection oversight. However, there is a need to improve the accuracy and reduce the false alarm rate. Therefore, this study aims to improve generic attack classification by implementing two hybridized decision tree algorithms namely Naïve Bayes Decision tree (NBTree) and Logistic Model tree (LMT). The proposed hybridized methods were developed using the 10-fold cross-validation technique to avoid overfitting. The generic attack detector produced a 99.8% accuracy, an FPR score of 0.002 and an MCC score of 0.995. The performances of the proposed methods were better than the existing decision tree method. Similarly, the proposed method outperformed multi-classification methods for detecting generic attacks. Hence, it is recommended to implement hybridized decision tree method for detecting generic attacks on a computer network.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.82-85
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• 2008

고객의 기호와 요구에 부응하는 서비스의 제공을 위해 영화 요소 중 정확한 장르의 분류는 고객의 선택에 있어 중요한 문제이다. 기존의 수작업에 의한 장르 분류는 시간과 비용, 신뢰성 등에서 비효율적이다. 이러한 문제의 해결을 위해 영화 시놉시스(Synopsis) 기반의 기계학습 방법은 효율적인 대안이 될 수 있다. 본 논문에서는 대다수 영화서비스 주체가 보유하고 있는 시놉시스 정보를 기반으로 하여 기계학습을 이용한 영화장르 분류에 관한 하나의 정형화된 방법을 제시한다. 기계학습 Algorithm 중 LibSVM, RandomComittee, LMT, NaiveBayes, PART Algorithm 을 이용하여 Algorithm 별, 장르별 분류 정확도를 측정하여 비교한다.

• The Mathematical Education
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• v.48 no.4
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• pp.399-417
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• 2009

The purpose of this study was to explore the adaptability of U.S. multiple-choice items to measure Mathematical Knowledge for Teaching (MKT) in Korea. For this purpose, the authors selected the number and operations form B which was developed by Learning Mathematics for Teaching (LMT) project at the University of Michigan and then adapted items in terms of general cultural context, school cultural context, mathematical substances, and language in Korea. The survey was administrated to 77 Korean in-service teachers who had more than three years of teaching experiences. Based on the survey, the authors compared the data to that of U.S. teachers who had participated California's Mathematics Professional Development Institute. As a result, the survey measures less knowledge Korean teachers than more knowledgable Korean teachers and there are strong correlations of relative item difficulties between Korean teachers and U.S. teachers for both Content Knowledge (CK) items and Knowledge of Content and Students (KCS) items. This study implies the future direction for developing items to measure teacher knowledge as well as designing effective teacher education programs.