• Title/Summary/Keyword: Convergence Structure

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Partial EBG Structure with DeCap for Ultra-wideband Suppression of Simultaneous Switching Noise in a High-Speed System

  • Kwon, Jong-Hwa;Kwak, Sang-Il;Sim, Dong-Uk;Yook, Jong-Gwan
    • ETRI Journal
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    • v.32 no.2
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    • pp.265-272
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    • 2010
  • To supply a power distribution network with stable power in a high-speed mixed mode system, simultaneous switching noise caused at the multilayer PCB and package structures needs to be sufficiently suppressed. The uni-planar compact electromagnetic bandgap (UC-EBG) structure is well known as a promising solution to suppress the power noise and isolate noise-sensitive analog/RF circuits from a noisy digital circuit. However, a typical UC-EBG structure has several severe problems, such as a limitation in the stop band's lower cutoff frequency and signal quality degradation. To make up for the defects of a conventional EBG structure, a partially located EBG structure with decoupling capacitors is proposed in this paper as a means of both suppressing the power noise propagation and minimizing the effects of the perforated reference plane on the signal quality. The proposed structure is validated and investigated through simulation and measurement in both frequency and time domains.

THE N-TH PRETOPOLOGICAL MODIFICATION OF CONVERGENCE SPACES

  • Park, Sang-Ho
    • Communications of the Korean Mathematical Society
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    • v.11 no.4
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    • pp.1087-1094
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    • 1996
  • In this paper, we introduce the notion of the n-th pretopological modification. Also, we find some properties which hold between convergence quotient maps and n-th pretopological modifications.

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A Study on Optimization of Structure with Limit State Constraints (한계상태를 고려한 구조물의 최적화에 관한 연구)

  • Kim, Kee-Dae
    • Journal of the Korean Society of Industry Convergence
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    • v.7 no.2
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    • pp.181-186
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    • 2004
  • This study presents a optimization of structure, in which constraints contain the conditions of stress and serviceability, while the sequential linear programming method (SLP) is used as a rational approach. The optimum design results contained on the limit state constraints are compared with those obtained by the only stress and ministry of construction enacted standard plans. A simple slab bridge is analysed numerically for illustration of the structural optimization. It may be asserted that serviceability constraints is very important to a structure design.

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Case Study for Analysis of Technology Convergence Structure with Social Network Analysis (기술융합 구조 분석을 위한 사례연구: 2-mode 네트워크분석 활용)

  • Lee, Kwang-Min;Hong, Jae-Bum
    • Journal of Technology Innovation
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    • v.24 no.2
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    • pp.1-20
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    • 2016
  • This case is to analyze the structure of technology convergence with social network analysis. More specifically, the convergence structure among input technologies mediated with products is analyzed with 2-mode social network analysis. Products are identified in project's goal and coded as the Korea Standard Industrial Classification. The input technologies are coded as the National Science Technology Classification. The subjects were 401 R&D projects applied to '2012 Convergence Technology Development Project for Small and Medium Businesses' promoted by Korea Technology & Information Promotion Agency for Small and Medium Enterprises. IT sectors had the structure of a particular input technology connected to many products, BT sectors also had a few input technology connected to many products but most were connected to specific products. Therefore We have realized that each convergence area had different convergence structure. There were the difference of connectivity centrality between input technologies and input technologies mediated with products. For IT sectors, the embedded S/W were the highest in both cases. For BT sectors, functional cosmetic development and fermentation technology were the highest in input technologies but fermentation technology was not the highest in input technologies mediated with products. This case defines the convergence based on the real projects and the use for managing and planing projects. Therefore, this case was to make a tool to analyze and design technology convergence projects.

Structural Convergence Improvement Schemes on Adaptive Control Redesigning a Lyapunov's Function (Lyapunov 함수를 재설계한 적응제어외의 구조적 수렴향상 방법에 대한 연구)

  • Kang, Hoon
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.1
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    • pp.1-9
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    • 1989
  • The convergence analysis of adavtive control schemes has been studied over the past decades, but the importance of structure to fast conversgece of adaptive control systems is still a controversial issue. This paper deals with the relative improvement of the exponential rate of convergence in adaptive error models. The Lyapunov's direct method is applied to adaptive control systems in order to improve the convergence rate by modifying the feedback structure of the error systems. Some simulation examples are illustrated to show fast convergence and robustness of these schemes.

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The Structure and the Convergence Characteristics Analysis on the Generalized Subband Decomposition FIR Adaptive Filter in Wavelet Transform Domain (웨이블릿 변환을 이용한 일반화된 서브밴드 분해 FIR 적응 필터의 구조와 수렴특성 해석)

  • Park, Sun-Kyu;Park, Nam-Chun
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.4
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    • pp.295-303
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    • 2008
  • In general, transform domain adaptive filters show faster convergence speed than the time domain adaptive filters, but the amount of calculation increases dramatically as the filter order increases. This problem can be solved by making use of the subband structure in transform domain adaptive filters. In this paper, to increase the convergence speed on the generalized subband decomposition FIR adaptive filters, a structure of the adaptive filter with subfilter of dyadic sparsity factor in wavelet transform domain is designed. And, in this adaptive filter, the equivalent input in transform domain is derived and, by using the input, the convergence properties for the LMS algorithm is analyzed and evaluated. By using this sub band adaptive filter, the inverse system modeling and the periodic noise canceller were designed, and, by computer simulation, the convergence speeds of the systems on LMS algorithm were compared with that of the subband adaptive filter using DFT(discrete Fourier transform).

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Accuracy Improvement of Pig Detection using Image Processing and Deep Learning Techniques on an Embedded Board (임베디드 보드에서 영상 처리 및 딥러닝 기법을 혼용한 돼지 탐지 정확도 개선)

  • Yu, Seunghyun;Son, Seungwook;Ahn, Hanse;Lee, Sejun;Baek, Hwapyeong;Chung, Yongwha;Park, Daihee
    • Journal of Korea Multimedia Society
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    • v.25 no.4
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    • pp.583-599
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    • 2022
  • Although the object detection accuracy with a single image has been significantly improved with the advance of deep learning techniques, the detection accuracy for pig monitoring is challenged by occlusion problems due to a complex structure of a pig room such as food facility. These detection difficulties with a single image can be mitigated by using a video data. In this research, we propose a method in pig detection for video monitoring environment with a static camera. That is, by using both image processing and deep learning techniques, we can recognize a complex structure of a pig room and this information of the pig room can be utilized for improving the detection accuracy of pigs in the monitored pig room. Furthermore, we reduce the execution time overhead by applying a pruning technique for real-time video monitoring on an embedded board. Based on the experiment results with a video data set obtained from a commercial pig farm, we confirmed that the pigs could be detected more accurately in real-time, even on an embedded board.

A Study on the Improvement of the Defense-related International Patent Classification using Patent Mining (특허 마이닝을 이용한 국방관련 국제특허분류 개선 방안 연구)

  • Kim, Kyung-Soo;Cho, Nam-Wook
    • Journal of Korean Society for Quality Management
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    • v.50 no.1
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    • pp.21-33
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    • 2022
  • Purpose: As most defense technologies are classified as confidential, the corresponding International Patent Classifications (IPCs) require special attention. Consequently, the list of defense-related IPCs has been managed by the government. This paper aims to evaluate the defense-related IPCs and propose a methodology to revalidate and improve the IPC classification scheme. Methods: The patents in military technology and their corresponding IPCs during 2009~2020 were utilized in this paper. Prior to the analysis, patents are divided into private and public sectors. Social network analysis was used to analyze the convergence structure and central defense technology, and association rule mining analysis was used to analyze the convergence pattern. Results: While the public sector was highly cohesive, the private sector was characterized by easy convergence between technologies. In addition, narrow convergence was observed in the public sector, and wide convergence was observed in the private sector. As a result of analyzing the core technologies of defense technology, defense-related IPC candidates were identified. Conclusion: This paper presents a comprehensive perspective on the structure of convergence of defense technology and the pattern of convergence. It is also significant because it proposed a method for revising defense-related IPCs. The results of this study are expected to be used as guidelines for preparing amendments to the government's defense-related IPC.

Strongly coupling partitioned scheme for enhanced added mass computation in 2D fluid-structure interaction

  • Lefrancois, Emmanuel;Brandely, Anais;Mottelet, Stephane
    • Coupled systems mechanics
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    • v.5 no.3
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    • pp.235-254
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    • 2016
  • A numerical model for fluid-structure interactions (abbr. FSI) is presented in the context of sloshing effects in movable, partially filled tanks to improve understanding of interactions between the fluid and the dynamics of a tank flexibly attached to a vehicle. The purpose of this model is to counteract the penalizing impact of the added mass effect on classical partitioned FSI coupling scheme: the proposed investigation is based on an added mass corrected version of the classical strongly coupled partitioned scheme presented in (Song et al. 2013). Results show that this corrected version systematically allows convergence to the coupled solution. In the rare cases where convergence is already obtained, the corrected version significantly reduces the number of iterations required. Finally, it is shown that the convergence limit imposed by added mass effect for the non-corrected coupling scheme, is directly dependent on the aspect ratio of the fluid domain and highly related to the precision order of the temporal discretization scheme.