• Title/Summary/Keyword: Multi-Port

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A Review of the Possible Causes of Negative Source Impedance in Fluid Machines (유체기계에 있어서 부의 음원 임피던스의 원인에 관한 고찰)

  • ;Keith S. Peat
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.3
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    • pp.76-82
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    • 2001
  • Most fluid machines can be considered as periodic noise sources when operated under constant conditions, which allows for a frequency domain representation of the source and the associated acoustic field In the duct. In such a representation, the source is characterized by frequency-dependent values of both strength and impedance. Although knowledge of these values can be gained by either experimentation or by modeling, one-port acoustic characteristics of an in-duct source with high flow velocity, high temperature, and high sound level can be measured only by the multiload method using an overdetermined set of open pipes with different lengths as applied loads. However, the problem is that negative source resistances have been often measured. This paper reviews the possible causes of the problem, with reference to experimental and theoretical results, in an attempt to clarify the issue. A new interpretation is given for the violation of basic assumptions and the defect in the algorithm of multiload method. The major cause and mechanism of the problem is due to the violation of time invariance assumption of the source and the load impedance can seriously affect the final measured result of source impedance.

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Evaluation of Seismic Performance of Takahama Wharf Using Nonlinear Effective Stress Analysis (비선형 유효응력해석을 이용한 Takahama 잔교식 안벽의 내진성능 평가)

  • Tran, Nghiem Xuan;Lee, Jin-sun;Kim, Sung-Ryul
    • Journal of the Korean Geotechnical Society
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    • v.33 no.4
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    • pp.47-56
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    • 2017
  • Aseismic designs of pile-supported wharves are commonly performed utilizing simplified dynamic analyses, such as multi-mode spectral analyses. Simplified analyses can be useful for evaluating the limit state of structures. However, several pile-supported wharves, that have been damaged during past earthquakes, have shown that soil deformation and soil-pile dynamic interaction significantly affect the entire behavior of structures. Such behavior can be captured by performing nonlinear effective stress analyses, which can properly consider the dynamic interactions among the soil-pile-structure. The present study attempts to investigate the earthquake performance of a pile-supported wharf utilizing a three-dimensional numerical method. The damaged pile-supported wharf at the Kobe Port during the Hyogo-ken Nambu earthquake (1995) is selected to verify the applicability of the numerical modeling. Analysis results showed a suitable agreement with the observations on the damaged wharf, and the significant effect of excess pore pressure development and pile-soil dynamic interaction on the seismic performance of the wharf.

Speaker Detection System for Video Conference (영상회의를 위한 화자 검출 시스템)

  • Lee, Byung-Sun;Ko, Sung-Won;Kwon, Heak-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.5
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    • pp.68-79
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    • 2003
  • In this paper, we propose a system that detects the current speaker in multi-speaker video conference by using lip motion. First, the system detects the face and lip area of each of the speakers using face color and shape information. Then, to detect the current speaker, it calculates the change between the current frame and the previous frame. To accomplish this, we used two CCD cameras. One is a general CCD camera, the other is a PTZ camera controlled by RS-232C serial port. The result is a system capable of detecting the face of current speaker in a video feed with more than three people, regardless of orientation of the faces. With this system, it only takes 4 to 5 seconds to zoom in on the speaker from the initial image. Also, it is amore efficient image transmission system for such things as video conference and internet broadcasting because it offers a face area screen at a resolution of 320X240, while at the same time providing a whole background screen.

A Study on the Automatic Lexical Acquisition for Multi-lingustic Speech Recognition (다국어 음성 인식을 위한 자동 어휘모델의 생성에 대한 연구)

  • 지원우;윤춘덕;김우성;김석동
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.6
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    • pp.434-442
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    • 2003
  • Software internationalization, the process of making software easier to localize for specific languages, has deep implications when applied to speech technology, where the goal of the task lies in the very essence of the particular language. A greatdeal of work and fine-tuning has gone into language processing software based on ASCII or a single language, say English, thus making a port to different languages difficult. The inherent identity of a language manifests itself in its lexicon, where its character set, phoneme set, pronunciation rules are revealed. We propose a decomposition of the lexicon building process, into four discrete and sequential steps. For preprocessing to build a lexical model, we translate from specific language code to unicode. (step 1) Transliterating code points from Unicode. (step 2) Phonetically standardizing rules. (step 3) Implementing grapheme to phoneme rules. (step 4) Implementing phonological processes.

Real-time Classification of Internet Application Traffic using a Hierarchical Multi-class SVM

  • Yu, Jae-Hak;Lee, Han-Sung;Im, Young-Hee;Kim, Myung-Sup;Park, Dai-Hee
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.5
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    • pp.859-876
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    • 2010
  • In this paper, we propose a hierarchical application traffic classification system as an alternative means to overcome the limitations of the port number and payload based methodologies, which are traditionally considered traffic classification methods. The proposed system is a new classification model that hierarchically combines a binary classifier SVM and Support Vector Data Descriptions (SVDDs). The proposed system selects an optimal attribute subset from the bi-directional traffic flows generated by our traffic analysis system (KU-MON) that enables real-time collection and analysis of campus traffic. The system is composed of three layers: The first layer is a binary classifier SVM that performs rapid classification between P2P and non-P2P traffic. The second layer classifies P2P traffic into file-sharing, messenger and TV, based on three SVDDs. The third layer performs specialized classification of all individual application traffic types. Since the proposed system enables both coarse- and fine-grained classification, it can guarantee efficient resource management, such as a stable network environment, seamless bandwidth guarantee and appropriate QoS. Moreover, even when a new application emerges, it can be easily adapted for incremental updating and scaling. Only additional training for the new part of the application traffic is needed instead of retraining the entire system. The performance of the proposed system is validated via experiments which confirm that its recall and precision measures are satisfactory.

Hardware Synthesis From Coarse-Grained Dataflow Specification For Fast HW/SW Cosynthesis (빠른 하드웨어/소프트웨어 통합합성을 위한 데이타플로우 명세로부터의 하드웨어 합성)

  • Jung, Hyun-Uk;Ha, Soon-Hoi
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.5
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    • pp.232-242
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    • 2005
  • This paper concerns automatic hardware synthesis from data flow graph (DFG) specification for fast HW/SW cosynthesis. A node in BFG represents a coarse grain block such as FIR and DCT and a port in a block may consume multiple data samples per invocation, which distinguishes our approach from behavioral synthesis and complicates the problem. In the presented design methodology, a dataflow graph with specified algorithm can be mapped to various hardware structures according to the resource allocation and schedule information. This simplifies the management of the area/performance tradeoff in hardware design and widens the design space of hardware implementation of a dataflow graph compared with the previous approaches. Through experiments with some examples, the usefulness of the proposed technique is demonstrated.

Design and Implementation of Monitoring System for Submarine Optical fiber Cable Work (해저 광케이블 작업을 위한 모니터링 시스템의 설계 및 구현)

  • 이태오;정성훈;임재홍
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.205-208
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    • 2002
  • When establishing the submarine optical fiber table between international and domestic, marine survey in advance it grasps the submarine geological features which is accurate and a depth of water condition. And the route which is safe for selecting and submarine optical fiber cable laying it is a work which secures an ease one location. If also, the PLGR the submarine of optical fiber table root the sea contamination material (rope, wire and net) it removes in advance and if the submarine of the optical fiber cable ease it does to arrive safely. And it is a work the Plough and ROV laying work hour laying work efficiency improvement and laying equipment it will be able to protect. So, This paper presents the monitoring system of ship information management and operation for marine survey and PLGR work in submarine optical fiber table construction enterprise. In order to achieve these purpose, overall serial multi-port communication modulo of configuration, realtime processing for management and operation of receiving data, realtime graph and a printout are described.

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A Study on the IUU Governance System of Regional Fishery Management Organization and Major State (국제 지역 수산 관리 기구와 주요 국가의 IUU 통제제도 연구)

  • Park, Min-Gyu
    • The Journal of Fisheries Business Administration
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    • v.41 no.3
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    • pp.103-127
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    • 2010
  • The FAO reports that IUU fishing activities have widespread economic, social, and management consequences, including depriving legitimate fishers of harvest opportunities. It affects all fisheries from small scale to industrial. It also affects the ability of governments to support sustainable livelihoods for fishers and, more broadly, to achieve food security. The complexity of IUU requires various measures to combat IUU fishing such as adoption of IUU vessel lists; stronger port State controls; improved monitoring, control and surveillance (MCS); implementation of market-related measures to help ensure compliance; and capacity-building assistance. Trade and market measures reduce opportunities for IUU fishing activities by precluding or impeding access to markets for IUU product in a manner consistent with international law. ICCAT, CCAMLR, and IATTC, have put in place trade tracking programs or catch documentation schemes, and WCPFC is considering such a program. Vessel lists assist enforcement authorities in determining which vessels are or are not authorized to be fishing or conducting fishing support activities in specified areas. A number of RFMOs maintain records of IUU vessels: CCAMLR, IATTC, ICCAT, NAFO, NASCO, NPAFC, WCPFC. Section 608 of the US MSRA calling on the Secretary of Commerce, in consultation with the Secretary of State, and in cooperation with relevant regional fishery management councils and any relevant advisory committees, to take actions to improve the effectiveness of international fishery management organizations in conserving and managing stocks under their jurisdiction. EU IUU Regulation entered into force on 1 January 2010, was intended to regulate the highly complex multi-channel fisheries supply system of the European Community (EC) in an effort to improve global fisheries sustainability.

Evaluation of Discharge Current Employing Generalized Energy Method and Integral Ohm's Law Using Finite Element Method (유한요소법을 이용한 일반화된 에너지법과 옴의 적분법에 의한 방전 전류 계산)

  • Lee, Ho-Young;Kim, Hong-Joon;Lee, Se-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.2
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    • pp.357-361
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    • 2011
  • The terminal current in voltage driven systems is an essential role for characterizing the pattern of electric discharge such as corona, breakdown, etc. Until now, to evaluate this terminal current, Sato's equation has been widely used in areas of high voltage and plasma discharge. Basically Sato's equation was derived by using the energy balance equation and its final form described physical meaning explicitly. To give more general abilities in Sato's equation, we present a generalized approach by directly using the Poynting's theorem incorporating the finite element method. When the magnetic field effect or the time-dependent voltage source is considered, this generalized energy method can be easily applicable to those problems with any dielectric media such as gas, fluid, and solid. As an alternative approach, the integral Ohm's law resulting in small numerical errors has an ability to be applied to multi-port systems. To test the generalized energy method and integral Ohm's law, first, the results from two prosed methods were compared to those from Sato's approach and an analytic solution in parallel plane electrodes. After verification, the generalized method was applied to the tip-sphere electrodes for evaluating the terminal current with three carriers and the Fowler-Nordheim field emission condition. From these results, we concluded that the generalized energy method can be a consistent technique for evaluating the discharge current with various dielectric materials or large magnetic field.

Dynamic Analysis for the Mooring Safety at KwangYang Port (광양 제품부두의 계류안정성 해석)

  • Kim, Young-Bok;Jeong, Tae-Gweon;Kim, Se-Won;Kim, Jung-Yeop;Kim, Young-Hun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.6
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    • pp.423-428
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    • 2010
  • This study is aiming to find one of reasonable guidelines to select a proper berthing ship at Kwang Yang harbors for loading/unloading for the POSCO(Pohang Steel Co. Ltd.). For dynamic analysis for the moored ships, the selection of subjected vessels has to be given the priority, so that the motion characteristics are figured out. The calculation of the dynamic fluid forces and wave, wind and current forces in time domain are followed. Then, the dynamic mooring analyses are performed. This study might contribute to make a new guideline by which the proper sized and loaded ships could be moored safety at the berths of Kwang Yang Harbor.