• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.1
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• pp.7-11
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• 2010

In this paper, we propose an improved speech/music discrimination method based on a feature combination and dimensionality reduction approach. To improve discrimination ability, we use a feature based on spectral duration analysis and employ the hierarchical dimensionality reduction (HDR) method to reduce the effect of correlated features. Through various kinds of experiments on speech and music, it is shown that the proposed method showed high discrimination results when compared with conventional methods.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.33-38
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• 2012

The wafer positioning robot in the semiconductor industry is required to operate at high speed for the improvement of productivity. The residual vibration caused by the high speed of the wafer positioning robot, however, makes the life of the robot shorter and the cycle time longer. In this study, the input shaping and the path of the system are designed for the reduction of the residual vibration and the improvement of the cycle time. The followings are the process for the reduction and the improvement; 1) System modeling of the wafer positioning robot, 2) Verification of dynamic characteristics of the wafer positioning robot, 3) Input shaping plan using impulse response reiteration, 4) Simulation test using SIMULINK program, 5) Analysis of result.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.622-627
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• 2014

A method to reduce the specific absorption rate(SAR) of the antenna for WiMAX mobile communication is proposed in this paper. The SAR reduction is achieved by miniaturizing the physical size of the antenna for the given resonance frequency by devising a metamaterial-composite right- and left-handed(CRLH) configuration-based radiator much smaller than the quarter-guided wavelength adopted a lot in the conventional planar inverted F antenna(PIFA) or modified monopole antenna. The proposed antenna is placed near the head-phantom and its SAR is evaluated by the full-wave simulations(SEMCAD X), where the metamaterial-inspired antenna is shown to have the lower value than a modified monopole as the reference in terms of the SAR.

• Land and Housing Review
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• v.11 no.1
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• pp.95-101
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• 2020

In the past few decades, the global population growth and rapid economic development have resulted in significant increases in building energy consumption. To reduce greenhouse-gas emissions and building energy consumption, building materials and energy technologies must be optimized. Building retrofitting is a more efficient method than reconstruction to improve the building energy performance. In order to improve the energy performance of existing buildings, this study proposed energy-efficiency retrofit plans and derived cost-effective retrofit plan. The energy efficient retrofit method is achieved through the packaging of energy technology and the energy and cost reduction effect of the energy efficiency retrofit package are analyzed. As a result of the study, the energy-efficiency retrofit package showed an energy reduction effect of up to 60% or more and a construction cost reduction of about 30%. This study argues that optimal energy and construction cost reduction of existing buildings are possible through the packaging of energy efficiency technology.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.543-546
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• 2008

In the present study, the effect of cold reduction ratio on the spherodization rate of SK85 high carbon steel sheet was investigated. High carbon steel sheet fabricated by POSCO was soaked at $800^{\circ}C$ for 2 hr in a box furnace and then treated at $570^{\circ}C$ for 5 min in a salt bath furnace followed by water quenching to obtain a fine pearlite structure. Cold rolling was conducted on the sheets of fine pearlite by reduction ratios of 20, 30, and 40 % and heat treatment for spheroidization was carried out at $720^{\circ}C$ for the various time intervals from 0.1 to 32 hrs. Area fraction of spheroidized cementite was measured with an image analyzer as a function of cold reduction ratios and duration times.

• ETRI Journal
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• v.41 no.3
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• pp.298-307
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• 2019

This paper investigates the use of the inverse-free sparse Bayesian learning (SBL) approach for peak-to-average power ratio (PAPR) reduction in orthogonal frequency-division multiplexing (OFDM)-based multiuser massive multiple-input multiple-output (MIMO) systems. The Bayesian inference method employs a truncated Gaussian mixture prior for the sought-after low-PAPR signal. To learn the prior signal, associated hyperparameters and underlying statistical parameters, we use the variational expectation-maximization (EM) iterative algorithm. The matrix inversion involved in the expectation step (E-step) is averted by invoking a relaxed evidence lower bound (relaxed-ELBO). The resulting inverse-free SBL algorithm has a much lower complexity than the standard SBL algorithm. Numerical experiments confirm the substantial improvement over existing methods in terms of PAPR reduction for different MIMO configurations.

• Electronics and Telecommunications Trends
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• v.34 no.2
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• pp.83-91
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• 2019

In this article, we introduce examples and technologies relating to particulate matter (PM) reduction technology, for the purpose of reducing PM that harms health and affects the entire industry such as dust-sensitive semiconductor industry. First, the definition of PM and how it is generated is explained, including its effects on the human body. In addition, various methods for measuring PM are described, including examples of the restrictions on the operation of polluting vehicles and emission reduction devices. Finally, we describe techniques relating to the reduction and forecasting of PM.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.8
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• pp.13-18
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• 2018

The purpose of this study was to study on the estimation of green remodeling energy reduction tool in building construction. Green Remodeling Decision System that can predict the energy reduction effect in green remodeling is developed as a tool for simple remodeling of green remodeling considering users' convenience, so that it can quickly and comprehensively determine power peak load reduction factor technology. A preliminary simulation result of a short preliminary remodeling evaluation is DB. It will be developed as a tool that can be easily accessed by users such as web and apps.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.81-87
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• 2018

This research was done to investigate the bioreduction characteristics of perchlorate in raw sewage because sewage contains biodegradable organics and various microorganisms for biological perchlorate reduction. Two different types of sewage were tested for biological perchlorate reduction in the flasks. Sewage A was collected from the screening equipment and sewage B was collected from the primary settlement in the municipal wastewater treatment facilities. Perchlorate was completely reduced within 72hours from 8.2 and 10.4 mg/L in the sewage A and sewage B flask tests. When perchlorate and nitrate were added in sewage A, both perchlorate and nitrate were reduced. However, perchlorate and nitrate removal rates were 9.3% and 64.0% at 72hours in sewage B. Perchlorate reduction was significantly inhibited by high salinity(0.5% NaCl) in the sewage A and B. These results showed the sewage has potential for the biological perchlorate reduction in the sewage pipe.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.31-36
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• 2021

RNA sequencing (RNA-Seq) is a technology that facilitates transcriptome analysis using next-generation sequencing (NSG) tools. Information on the quantity and sequences of RNA is vital to relate our genomes to functional protein expression. RNA-Seq data are characterized as being high-dimensional in that the number of variables (i.e., transcripts) far exceeds the number of observations (e.g., experiments). Given the wide range of dimensionality reduction techniques, it is not clear which is best for RNA-Seq data analysis. In this paper, we study the effect of three dimensionality reduction techniques to improve the classification of the RNA-Seq dataset. In particular, we use PCA, SVD, and SOM to obtain a reduced feature space. We built nine classification models for a cancer dataset and compared their performance. Our experimental results indicate that better classification performance is obtained with PCA and SOM. Overall, the combinations PCA+KNN, SOM+RF, and SOM+KNN produce preferred results.