• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.8
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• pp.55-61
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• 2010

In this paper, we proposed selective extraction method of frequency information and PCA-ELM based diagnosis system for three-phase induction motors. As the first step for diagnosis procedure, DFT is performed to transform the acquired current signal into frequency domain. And then, frequency components are selected according to discriminate order calculated by variance As the next step, feature extraction is performed by principal component analysis (PCA). Finally, we used the classifier based on Extreme Learning Machine (ELM) with fast learning procedure. To show the effectiveness, the proposed diagnostic system has been intensively tested with the various data acquired under different electrical and mechanical faults with varying load.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.523-530
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• 2008

There are many defects that cause the process improvement of lifecycle problems during software development. This paper propose the management method of risk items that removes and manages the lifecycle problems as well. For the similar projects, we can estimate defects and prepare to solve them by using domain expert knowledge and the state analysis of defect items, which can greatly improve the software process. This research provides solution of management of risk items problem and detection of defect transition and its prevention and causes that happen on software development. Also, In this paper propose to making quantity of degree and transition phase.

• BMB Reports
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• v.42 no.8
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• pp.516-522
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• 2009

SH2D4A, comprising a single SH2 domain, is a novel protein of the SH2 signaling protein family. We have previously demonstrated SH2D4A is expressed ubiquitously in various tissues and is located in the cytoplasm. In this study we investigated the function of SH2D4A in human embryonic kidney (HEK) 293 cells using interaction analysis, cell proliferation assays, and kinase activity detection. SH2D4A was found to directly bind to estrogen receptor $\alpha$ (ER$\alpha$), and prevent the recruitment of phospholipase C-$\gamma$ (PLC-$\gamma$) to ER$\alpha$. Moreover, we observed its inhibitory effects on estrogen-induced cell proliferation, involving the protein kinase C (PKC) signaling pathway. Together, these findings suggested that SH2D4A inhibited cell proliferation by suppression of the ER$\alpha$/PLC-$\gamma$/PKC signaling pathway. SH2D4A may be useful for the development of a new anti-cancer drug acting as an ER signaling modulator.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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• pp.895-906
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• 2000

A three dimensional linear frequency-domain lifting surface panel method was used for the aerodynamic analysis of axial flow type micro-fans. As proven by the duct modeling, the tip clearance of the micro-fans tested is large enough to ignore the calculated effect of the duct system. As the numerical results and experimental data agreed well in the operating point region, the method was applicable in the parametric studies to determine the design parameters of axial flow fans. Experiments on micro-fans were carried out based on KS B 6311. The newly designed micro-fan showed improvements in both static pressure rise and volumetric flow rate compared to the existing fans at a given operating condition. No detection of surging and the smooth characteristic curve proved the improvement in performance. To reduce the fan noise in the fan design, it was necessary to make use of the frequency spectrum analysis data. Measurement of sound pressure level for micro-fans was conducted based on KS B 6361 and KS A 0705. The peak - which occurs at blade passage frequency and its higher harmonics due to the fan noise - was not detected. This justifies the design methodology of the blade.

• ETRI Journal
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• v.38 no.1
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• pp.174-184
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• 2016

Information identification with image data by means of low-level visual features has evolved as a challenging research domain. Conventional text-based mapping of image data has been gradually replaced by content-based techniques of image identification. Feature extraction from image content plays a crucial role in facilitating content-based detection processes. In this paper, the authors have proposed four different techniques for multiview feature extraction from images. The efficiency of extracted feature vectors for content-based image classification and retrieval is evaluated by means of fusion-based and data standardization-based techniques. It is observed that the latter surpasses the former. The proposed methods outclass state-of-the-art techniques for content-based image identification and show an average increase in precision of 17.71% and 22.78% for classification and retrieval, respectively. Three public datasets - Wang; Oliva and Torralba (OT-Scene); and Corel - are used for verification purposes. The research findings are statistically validated by conducting a paired t-test.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.28-33
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• 2007

We present a space-time trellis coded OFDM system in flow fading channels. Generalized principal ratio combining (GPRC) is also analyzed theoretically in frequency domain. The analysis show that the decoding metric of GPRC include the metrics of maximum likelihood (ML) and PRC. The computer simulations with M-PSK modulation are obtained in frequency flat and frequency selective lading channels. The decoding complexity and simulation running times are also evaluated among the decoding schemes.

• The Journal of the Acoustical Society of Korea
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• v.23 no.7
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• pp.514-520
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• 2004

There are many techniques for underwater source localization. These are the methods based on TDOA (Time Difference Of Arrival) estimation. beamforming techniques and high resolution techniques, etc. In this Paper we estimate the underwater source position using MCPSP (Modified Cross Power Spectrum Phase) function that is calculated on frequency domain using sensors of small number. However, the performances of the localizing method based on MCPSP function drops greatly in the case of CW (Continuous Wave) signal . In this Paper we proposed the TDOA estimation method for pulsed CW signal. In the Proposed method we composed of new segment including a edge of ping. This segment was computed by short-time energy detection. With theoretical representation the performances of the proposed method were analyzed under various environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2B
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• pp.90-99
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• 2007

It might be more efficient that detections of distributed denial of service (DDoS) attacks are done in backbone domain than in individual local networks or links. However, because existing schemes for detecting DDoS attack symptoms have been focused on individual packets or flows, they require much higher computational complexities. In this paper, we propose an efficient method to detect DDoS attack symptoms in backbone networks. Unlike conventional schemes focused on individual packets or flows, the proposed method is carried at aggregate traffic level. So, our proposed schemes can be operated with very lower computational complexity, and can be run in very high-speed backbone networks.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.319-323
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• 2003

In this paper, we propose a hybrid transceiver for underwater acoustic communication, which allows the system to reduce complexity and increase robustness in time variant underwater channel environments. It is designed in the digital domain except for amplifiers and implemented by using a multiple digital signal processors (DSPs) system. The digital modulation technique is quadrature phase shift keying (QPSK) and frame synchronization is an energy (non-coherent) detection scheme based on the quadrature receiver structure. DSP implementation is based on block data parallel architecture (BDPA). We shaw experimental results in th? underwater anechoic basin at KRISO. The results indicate that the frame synchronization is performed without PLL. Also, we shaw that the adaptive equalizer can compensate frame synchronization error and the correction capability is dependent on the length of equalizer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.3
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• pp.489-497
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• 2009

Most of existent blind watermarking methods in frequency domain use coefficient relationship to detect the watermark without original image. But the change in coefficient values occurred when the original image was attacked by lossy JPEG compression or noise addition. So robustness of watermark detection was weaken. In order to solve these problems, this paper presents a robust watermarking method, which enables multiple watermark insertion. Also, in order to reduce errors in the detected value of watermarks according to small changes in the coefficient relationship when detecting watermarks, it set the change guard value for variation of the coefficients. The experimental results show that the proposed method has good image quality and is robust to various attacks such as the JPEG lossy compression, noise addition, etc.