• Title/Summary/Keyword: Time window

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An Efficient Management and Sliding Window Query for Real-Time Stream Data to Require frequent Update (빈번한 변경을 요구하는 실시간 스트림 데이터의 효율적 관리 및 슬라이딩 윈도우 질의)

  • Kim, Jin-Deog
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.3
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    • pp.509-516
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    • 2008
  • Recently, the operator modules to control external devices are concerned about automatic management system to process continuously changed signals. These signals are the stream data of which characteristics are several numbers. a short report interval and asynchronous report time. It is necessary that the system brings about high accuracy and real time process for stream data. The typical queries of these systems consist of the current query to search the latest signal value, the snapshot query at a past time, the sliding window query from a past time to current. In this paper, we propose the efficient method to manage the above signals by using a file structured database in small-size operating systems. We also propose a query model to accommodate various queries including the sliding window query. The file database in the QNX adopts a delta version and a shared memory buffering method for the resource limit of a small storage and a low computing power.

Damage assessment of shear buildings by synchronous estimation of stiffness and damping using measured acceleration

  • Shin, Soobong;Oh, Seong Ho
    • Smart Structures and Systems
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    • v.3 no.3
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    • pp.245-261
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    • 2007
  • Nonlinear time-domain system identification (SI) algorithm is proposed to assess damage in a shear building by synchronously estimating time-varying stiffness and damping parameters using measured acceleration data. Mass properties have been assumed as the a priori known information. Viscous damping was utilized for the current research. To chase possible nonlinear dynamic behavior under severe vibration, an incremental governing equation of vibrational motion has been utilized. Stiffness and damping parameters are estimated at each time step by minimizing the response error between measured and computed acceleration increments at the measured degrees-of-freedom. To solve a nonlinear constrained optimization problem for optimal structural parameters, sensitivities of acceleration increment were formulated with respect to stiffness and damping parameters, respectively. Incremental state vectors of vibrational motion were computed numerically by Newmark-${\beta}$ method. No model is pre-defined in the proposed algorithm for recovering the nonlinear response. A time-window scheme together with Monte Carlo iterations was utilized to estimate parameters with noise polluted sparse measured acceleration. A moving average scheme was applied to estimate the time-varying trend of structural parameters in all the examples. To examine the proposed SI algorithm, simulation studies were carried out intensively with sample shear buildings under earthquake excitations. In addition, the algorithm was applied to assess damage with laboratory test data obtained from free vibration on a three-story shear building model.

A Study on Window Based Real-Time Static Background Modeling and Object Extraction (윈도우 기반의 실시간 정지 백그라운드 모델링과 오브젝트 추출에 관한 연구)

  • Park, Jun-Hun;Choi, Chang-Gyu;Cho, Jeong-Hyun;Kim, Sung-Ho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2003.11a
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    • pp.49-52
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    • 2003
  • 본 논문에서는 실시간 감시 시스템의 응용분야를 위한 백그라운드 모델링과 업데이트 그리고 오브젝트 추출 시스템을 설계 구현한다. 일반적인 감시 시스템은 백그라운드의 모델링(background modeling)과 오브젝트의 검출(object detection), 오브젝트의 추적(tracking)으로 구성된다. 실시간 감시시스템을 가능하게 하기 위해서는 작은 시간 복잡도(low time complexity)로 백그라운드와 오브젝트를 검출할 수 있어야 하고 실외환경(outdoor)의 노이즈(noise)를 반영할 수 있어야 한다. 기존에는 빠른 백그라운드 모델링을 위해 분산, 평균, 최빈값 등을 사용한 연구들이 있었다. 이러한 방법들은 빠른 수행 속도를 보장하지만 노이즈를 오브젝트로 검출하는 문제점이 있다. 또 다른 연구 분야인 메디안(median) 검출 방법은 실외환경에 존재하는 노이즈 반영에 적합한 반면, 정렬(sorting) 연산에 많은 시간이 소요된다. 본 논문은 윈도우(Window) 기반의 러닝 윈도우 리스트(Running Window List)를 이용하여 메디안 정렬 시간을 최소화하고 실시간으로 백그라운드 모델링, 오브젝트 검출, 백그라운드 업데이트를 할 수 있는 방법을 제안한다.

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Image Processed Tracking System of Multiple Moving Objects Based on Kalman Filter

  • Kim, Sang-Bong;Kim, Dong-Kyu;Kim, Hak-Kyeong
    • Journal of Mechanical Science and Technology
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    • v.16 no.4
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    • pp.427-435
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    • 2002
  • This paper presents a development result for image processed tracking system of multiple moving objects based on Kalman filter and a simple window tracking method. The proposed algorithm of foreground detection and background adaptation (FDBA) is composed of three modules: a block checking module(BCM), an object movement prediction module(OMPM), and an adaptive background estimation module (ABEM). The BCM is processed for checking the existence of objects. To speed up the image processing time and to precisely track multiple objects under the object's mergence, a concept of a simple window tracking method is adopted in the OMPM. The ABEM separates the foreground from the background in the reset simple tracking window in the OMPM. It is shown through experimental results that the proposed FDBA algorithm is robustly adaptable to the background variation in a short processing time. Furthermore, it is shown that the proposed method can solve the problems of mergence, cross and split that are brought up in the case of tracking multiple moving objects.

A Two Window-Based marking algorithm for enhancing throughput fairness of assured services in a differentiated service network (차별서비스 네트워크에서 보장형 서비스의 전송률 공평성 향상을 위한 이중 윈도우 기반 마킹 알고리즘)

  • 조병규;황구연;이성근;장문석
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.147-151
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    • 2002
  • One of the main issues in Diffserv AS architecture is guaranteeing fairness among the flows which have their own QoS requirements. Because the methodology of resource allocation and traffic conditioning would affect the end-to-end QoS and backbone link utilization. In this paper, we propose a variant of TSW algorithm for enhancing fair bandwidth allocation and link utilization and presents performance evaluation between TSW & TS2W3C through NS-2 Simulations.

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The Improvement in Signal Integrity of FT-ICR MS (FT-ICR 질량분석기의 신호 충실성 향상)

  • Kim, Seung-Yong;Kim, Seok-Yoon;Kim, Hyun Sik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.201-204
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    • 2011
  • For efficient noise reduction in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrum, a new algorithm was proposed. The suggested algorithm reduces white and electrical noise, and it improves signal-to-noise ratio. This algorithm has been optimized to reduce the noise more efficiently using the traces of signal level. The algorithm has been efficiently combined with derivative window to improve the resolution as well S/N. Time domain data was corrected for DC voltage interference. $t^n$ window was applied in time domain data to improved the resolution. However, $t^n$ window can improve the signal resolution, it will also increase the noise level in frequency domain. Therefore, newly developed noise reduction algorithm will be applied to make a balance between resolving power and S/N ratio for magnitude mode. The trace algorithm can determine the current data point with several data points (mean, past data, calculated past data). In the current calculations, we assumed data points with S/N ratio more than 3 were considered as signal data points. After the windowing and noise reduction, both resolution and signal-to-noise ratio were improved. This algorithm is applicable more efficiently to frequency dependent noise and large size data.

Development of the wooden window design implementing D.I.Y. modular system (D.I.Y. Modular 방식을 도입한 목재 창 디자인 개발)

  • Kim, Jin-Young;Kim, Do-Yeon;Roh, Yang-Mi;Park, Hyo-Mi
    • Archives of design research
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    • v.17 no.4
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    • pp.401-404
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    • 2004
  • The proposal defines a Do It Yourself system that radically changes the traditional concept of window. it is based on a D.I.Y. system that allows the users to fully customize its windows according to his needs, combining a wood frame with different elements. At the same time, it is preserving the basic function of light and ventilation and defining a new aesthetic code. Despite the restriction of size and shape, the user can choose among many different elements to increase the space efficiency he needs and to give a more enjoyable perspective to the window both in and out door. Also, All the elements are standard and they can be mass-produced according to specific market needs. Therefore, the window of the future will not be just a thin membrane in between the inside and the outside, but it will also play an important "identification role. According to each individual pick, these new windows will help to give identify to anonymous metropolitan areas and to the people living within them.

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Angular Multiplexed Holographic Memory System using Moving Window on LCD (LCD에서 움직이는 창을 이용한 각다중화 홀로그래픽 메모리 시스템)

  • 김수길;김규태;김은수
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.9
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    • pp.70-76
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    • 1998
  • By controlling the pixel of a LCD spatial light modulator electronically, we made a real-time moving window passing through the light on a LCD spatial light modulator. By using this LCD moving window, we suggested an angular multiplexed holographic memory system and in case of windows of 10$\times$10 pixels and 2$\times$2 pixels the total numbers of address are 1,536 and 38,400, respectively. To demonstrate the feasibility of the proposed method, we recorded and reconstructed 30 images by 30 input addresses.

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A study on shearing die design for window roller housing and die manufacture (창호용 롤러 하우징의 전단금형 설계 및 제작에 관한 연구)

  • Kim, Sei-hwan;Choi, Kye-kwang
    • Design & Manufacturing
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    • v.8 no.1
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    • pp.35-39
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    • 2014
  • Window roller housings are durable because high-quality source materials such as stainless steel is used in making them. After a series of precise structure analysis, their design is optimized. They are subject to repetitive driving tests of more 100,000 times, durability tests, impact resistance tests, corrosion tests and others. For a long time, gaps often occur in press molded products owing to serious squareness deformation and flatness deformation of them. Severe burrs in press molded products require frequent grinding, which leads to short life cycle and rough or unreliable movement of assembled roller housing, which, in turn, causes product defects. This study focuses on developing measures to resolve existing defects and to improve lifespan of dies by designing and making a window roller shearing die.

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Using Skylines on Wavelet Synopses for CKNN Queries over Distributed Streams Processing

  • Wang, Ling;Zhou, TieHua;Kim, Kwang-Deuk;Lee, Yang-Koo;Ryu, Keun-Ho
    • Journal of Korea Spatial Information System Society
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    • v.11 no.2
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    • pp.7-12
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    • 2009
  • In this paper, we discuss the problem of continuous k.nearest neighbors (CKNN) monitoring over distributed streams wavelet synopses, which also considered sliding window structure under stream based kNN query. We developed traditional skylines techniques and propose a new method which called DR.skylines to process CKNN queries as a bandwidth.efficient approach. It tries to process CKNN queries on synopses for optimized sliding window time and space computation.

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