• Title/Summary/Keyword: engineering technique

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Low-Power Synchronization Technique for On-Chip Communication (온 칩 통신을 위한 저 전력 동기화 기술)

  • Lee, Jung-Hyun;Kim, Dong-Chul;Eo, Yung-Seon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.10
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    • pp.33-38
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    • 2011
  • A novel low-power synchronization technique is presented for the local synchronization. Since the proposed technique transmits an enable signal instead of a clock signal which consumes large power, it can considerably reduce the power consumption. The source-synchronization scheme which is widely adopted for the local synchronization is compared with the proposed technique. It is shown that the proposed low-power synchronization technique provides approximately 50% power saving.

First-Order Sensitivities for FACTS Devices using UPFC Ideal Transformer Model (UPFC 이상변압기 모델을 사용한 유연송전장치 일차민감도 해석)

  • Thomas W. Gedra;Seung-Won An
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.5
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    • pp.837-846
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    • 2004
  • This paper presents a screening technique for greatly reducing the computation involved in determining the optimal location and types of Flexible AC Transmission System (FACTS) devices in a large power system. The first-order sensitivities of the generation cost for various FACTS devices are derived. This technique requires solving only one optimal power flow (OPF) to obtain sensitivities with respect to FACTS device control variables for every transmission line To implement a sensitivity-based screening technique, we used a new UPFC model, which consists of an ideal transformer with a complex turns ratio and a variable shunt admittance. A S-bus system based on the IEEE 14-bus system was used to illustrate the technique.

High capacity multi-bit data hiding based on modified histogram shifting technique

  • Sivasubramanian, Nandhini;Konganathan, Gunaseelan;Rao, Yeragudipati Venkata Ramana
    • ETRI Journal
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    • v.40 no.5
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    • pp.677-686
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    • 2018
  • A novel data hiding technique based on modified histogram shifting that incorporates multi-bit secret data hiding is proposed. The proposed technique divides the image pixel values into embeddable and nonembeddable pixel values. Embeddable pixel values are those that are within a specified limit interval surrounding the peak value of an image. The limit interval is calculated from the number of secret bits to be embedded into each embeddable pixel value. The embedded secret bits can be perfectly extracted from the stego image at the receiver side without any overhead bits. From the simulation, it is found that the proposed technique produces a better quality stego image compared to other data hiding techniques, for the same embedding rate. Since the proposed technique only embeds the secret bits in a limited number of pixel values, the change in the visual quality of the stego image is negligible when compared to other data hiding techniques.

Optimized Space Vector Pulse-width Modulation Technique for a Five-level Cascaded H-Bridge Inverter

  • Matsa, Amarendra;Ahmed, Irfan;Chaudhari, Madhuri A.
    • Journal of Power Electronics
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    • v.14 no.5
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    • pp.937-945
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    • 2014
  • This paper presents an optimized space vector pulse-width modulation (OSVPWM) technique for a five-level cascaded H-bridge (CHB) inverter. The space vector diagram of the five-level CHB inverter is optimized by resolving it into inner and outer two-level space vector hexagons. Unlike conventional space vector topology, the proposed technique significantly reduces the involved computational time and efforts without compromising the performance of the five-level CHB inverter. A further optimized (FOSVPWM) technique is also presented in this paper, which significantly reduces the complexity and computational efforts. The developed techniques are verified through MATLAB/SIMULINK. Results are compared with sinusoidal pulse-width modulation (SPWM) to prove the validity of the proposed technique. The proposed simulation system is realized by using an XC3S400 field-programmable gate array from Xilinx, Inc. The experiment results are then presented for verification.

Reliability Evaluation Technique for Electrical Distribution Networks Considering Planned Outages

  • Hu, Bo;He, Xiao-Hui;Cao, Kan
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1482-1488
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    • 2014
  • The reliability evaluation of the electrical distribution networks (EDN) requires sufficient consideration of the effects of planned outages. The planned outages of the EDN can be divided, by outage models and their effects on the reliability into two major categories: by equipment and by feeder. After studying the characteristics of different categories of planned outages, this paper expands the classification of load points by outage time from 4 types to 7 types and defines corresponding reliability parameters for the different types. By using the section algorithm, this paper proposes a reliability evaluation technique of EDN considering equipment random failures and two categories of planned outages. The proposed technique has been applied to the RBTS-BUS6 test system and some practical EDNs in China. The study results demonstrate that the proposed technique is of higher practical value and can be used for evaluating the reliability performance of EDN more efficiently considering the planned outages.

k-path diffusion method for Multi-vision Display Technique among Smart Devices (k-path 확산 방법을 이용한 스마트 디바이스 간 멀티비전 디스플레이 기술)

  • Ren, Hao;Kim, Paul;Kim, Sangwook
    • Annual Conference of KIPS
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    • 2014.11a
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    • pp.1183-1186
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    • 2014
  • Our research is different form traditional to have some large LED screen grouping together to constitute multi-vision technique. In this paper, we purpose a method of using k-path diffusion method to build connect between the devices and find an optimal data transmission path. In second half of this paper, through practical application, we using this technique transmitting data successfully and achieving a simple Multi-vision effect. This technique possess smart devices and Wifi P2P's features, these features improve system's dynamic and decentralized processing ability make our technique has high scalability.

New Unsupervised Classification Technique for Polarimetric SAR Images

  • Oh, Yi-Sok;Lee, Kyung-Yup;Jang, Ge-Ba
    • Korean Journal of Remote Sensing
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    • v.25 no.3
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    • pp.255-261
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    • 2009
  • A new polarimetric SAR image classification technique based on the degree of polarization (DoP) and the co-polarized phase-difference (CPD) is presented in this paper. Since the DoP and the CPD of a scattered wave provide information on the randomness of the scattering and the type of scattering mechanisms, at first, the statistics of the DoP and CPD are examined with measured polarimetric SAR image data. Then, a DoP-CPD diagram with appropriate boundaries between six different classes is developed based on the SAR image. The classification technique is verified using the JPL AirSAR and ALOS PALSAR polarimetric data. The technique may have capability to classify an SAR image into six major classes; a bare surface, a village, a crown-layer short vegetation canopy, a trunk-layer short vegetation canopy, a crown-layer forest, and a trunk-dominated forest.

Efficient Implementation of GMDA-based DOA Technique Using Pre-training Phase Unwrapping for Source Localization

  • Sang-Ick Kang;Seongbin Kim;Sangmin Lee
    • Journal of Internet Technology
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    • v.21 no.3
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    • pp.841-847
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    • 2020
  • In this paper, a novel technique that improves the performance of generalized mixture decomposition algorithm (GMDA) based on pre-training phase unwrapping. From the investigation of the GMDA scheme, it was discovered that the conventional GMDA technique cannot fully consider phase unwrapping, because the estimated inter-channel phase difference (IPD) slope is initialized randomly. To avoid this phenomenon, the proposed GMDA approach initialized the IPD slope from the data of low-frequency bins. Experimental results show that comparing to the conventional GMDA technique, the proposed GMDA technique based on pre-training phase unwrapping obtains a lower estimation error. When integrated into a source localization system, the result of source localization is improved.

The Clustering Threshold Image Processing Technique in fMRI (핵자기 뇌기능 영상에서 군집경계기법을 이용한 영상처리법)

  • Jeong, Sun-Cheol;No, Yong-Man;Jo, Jang-Hui
    • Journal of Biomedical Engineering Research
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    • v.16 no.4
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    • pp.425-430
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    • 1995
  • The correlation technique has been widely used in ctRl data processing. The proposed CLT (clus- tering threshold) technique is a modified CCT (correlation coefficient threshold) technique and has many advantages compared with the conventional CCT technique. The CLT technique is explained by the following two steps. First, once the correlation coefficient map above the proper TH value is obtained using the CCT technique which is discrete and includes splash noise data, then the spurious pixels are rejected and the real neural activity pixels extracted using an nxn matrix box. Second, a clustering operation is performed by the two correction rules. The real neuronal activated pixels can be clustered and the false spurious pixels can be suppressed by the proposed CLT technique. The proposed CLT technique used in the post processing in ctRl has advantages over other existing techniques. It is especially proved to be robust in noisy environment.

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Analysis and Implementation of PS-PWAM Technique for Quasi Z-Source Multilevel Inverter

  • Seyezhai, R.;Umarani, D.
    • Journal of Electrical Engineering and Technology
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    • v.13 no.2
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    • pp.688-698
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    • 2018
  • Quasi Z-Source Multilevel Inverter (QZMLI) topology has attracted grid connected Photovoltaic (PV) systems in recent days. So there is a remarkable research thrust in switching techniques and control strategies of QZMLI. This paper presents the mathematical analysis of Phase shift- Pulse Width Amplitude Modulation (PS-PWAM) for QZMLI and emphasizes on the advantages of the technique. The proposed technique uses the maximum and minimum envelopes of the reference waves for generation of pulses and proportion of it to generate shoot-through pulses. Hence, it results in maximum utilization of input voltage, lesser switching loss, reduced Total Harmonic Distortion (THD) of the output voltage, reduced inductor current ripple and capacitor voltage ripple. Due to these qualities, the QZMLI with PS-PWAM emerges to be the best suitable for PV based grid connected applications compared to Phase shift-Pulse Width Modulation (PS-PWM). The detailed math analysis of the proposed technique has been disclosed. Simulation has been performed for the proposed technique using MATLAB/Simulink. A prototype has been built to validate the results for which the pulses were generated using FPGA /SPARTAN 3E.