• Title/Summary/Keyword: Time-variant

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Seismic assessment of R/C residential buildings with infill walls in Turkey

  • Korkmaz, Kasim Armagan;Kayhan, Ali Haydar;Ucar, Taner
    • Computers and Concrete
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    • v.12 no.5
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    • pp.681-695
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    • 2013
  • In 1999 Marmara and 2011 Van earthquakes in Turkey, majority of the existing buildings either sustained severe damage or collapsed. These buildings include masonry infill walls in both the interior and exterior R/C frames. The material of the masonry infill is the main variant, ranging from natural stones to bricks and blocks. It is demanding to design these buildings for satisfactory structural behavior. In general, masonry infill walls are considered by its weights not by interaction between walls and frames. In this study, R/C buildings with infill walls are considered in terms of structural behavior. Therefore, 5 and 8-story R/C buildings are regarded as the representative models in the analyses. The R/C representative buildings, both with and without infill walls were analyzed to determine the effects of structural behavior change. The differences in earthquake behavior of these representative buildings were investigated to determine the effects of infill walls leading structural capacity. First, pushover curves of the representative buildings were sketched. Aftermath, time history analyses were carried out to define the displacement demands. Finally, fragility analyses were performed. Throughout the fragility analyses, probabilistic seismic assessment for R/C building structures both with and without infill walls were provided. In this study, besides the deterministic assessment methodology, a probabilistic approach was followed to define structural effect of infill walls under seismic loads.

Carrier phase recovery algorithm for LDPC coded system (LDPC 코드를 이용한 위상 동기 알고리즘)

  • Lee Juhyung;Kim Namshik;Park Hyuncheol;Kim Pansu;Oh Dukgil;Lee Hojin
    • Proceedings of the IEEK Conference
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    • 2004.06a
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    • pp.43-46
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    • 2004
  • In this paper, we present a carrier phase estimation algorithm for LDPC coded systems. LDPC coded system can not achieve the ideal performance if phase offset is introduced by channel. However, the estimation of phase offset is very hard since the operating point of LDPC is very low SNR. To solve this problem, the algorithm using the tentative soft decision value and based on Maximum Likelihood (ML), was proposed in [2]. But this algorithm has problem which works only under constant phase offset. If phase offset is time variant, it has a severe degradation in performance. To solve this problem. we propose two types of estimators. symbol by symbol estimator: Unidirectional estimator (UDE) and hi-directional estimator (BDE), and sub-block estimator (SBE).

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Development of Product Specification Management System for Product Data Integration Framework in Customer-Oriented Manufacturing Enterprise (고객지향 수주생산 기업에서 제품정보 통합체계를 위한 제품사양관리시스템 구축)

  • Jung, Soon-Il;Kim, Jae-Gyun;Jang, Gil-Sang
    • IE interfaces
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    • v.21 no.1
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    • pp.18-32
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    • 2008
  • In recent, a general trend is observed towards more customized products and shorter product life cycles in manufacturing companies. In these companies, customers often wish to influence the product they order and to get a variant of product that meets their requirements. This environment is called as a customer-oriented manufacturing companies. This paper presents a procedure of product specification management for customer-oriented manufacturing companies by using product specification framework. This framework is founded on the product specification based product structure which is made of model, specification, function, and part. Also, a product specification management system(PSMS) is implemented by using the proposed product specification framework and is a core system in product data integration system. To illustrate an utilization of the proposed framework and procedure, a case of a ship engine product is applied. As a result, PSMS reduces delivery time and improves customer relationships. Moreover, the case shows that PSMS can be used as a tool for improving inter-department coordination within a company during product life cycle.

Camera Extrinsic Parameter Estimation using 2D Homography and LM Method based on PPIV Recognition (PPIV 인식기반 2D 호모그래피와 LM방법을 이용한 카메라 외부인수 산출)

  • Cha Jeong-Hee;Jeon Young-Min
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.2 s.308
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    • pp.11-19
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    • 2006
  • In this paper, we propose a method to estimate camera extrinsic parameter based on projective and permutation invariance point features. Because feature informations in previous research is variant to c.:men viewpoint, extraction of correspondent point is difficult. Therefore, in this paper, we propose the extracting method of invariant point features, and new matching method using similarity evaluation function and Graham search method for reducing time complexity and finding correspondent points accurately. In the calculation of camera extrinsic parameter stage, we also propose two-stage motion parameter estimation method for enhancing convergent degree of LM algorithm. In the experiment, we compare and analyse the proposed method with existing method by using various indoor images to demonstrate the superiority of the proposed algorithms.

Alternative splicing and expression analysis of High expression of osmotically responsive genes1 (HOS1) in Arabidopsis

  • Lee, Jeong-Hwan;Kim, Soo-Hyun;Kim, Jae-Joon;Ahn, Ji-Hoon
    • BMB Reports
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    • v.45 no.9
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    • pp.515-520
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    • 2012
  • High expression of osmotically responsive genes1 (HOS1), a key regulator of low temperature response and flowering time, encodes an E3 ubiquitin ligase in Arabidopsis. Here, we report characterization of a newly identified splice variant (HOS1-L) of HOS1. Comparative analyses revealed that HOS1-L has a longer 5' nucleotide sequence than that of the previously identified HOS1 (HOS1-S) and that its protein sequence was more conserved than that of HOS1-S in plants. HOS1-L transcripts were spatio-temporally more abundant than those of HOS1-S. The recovery rate of HOS1-S expression was faster than that of HOS1-L after cold treatment. Diurnal oscillation patterns of HOS1-L revealed that HOS1-L expression was affected by photoperiod. An in vitro pull-down assay revealed that the HOS1-L protein interacted with the ICE1 protein. HOS1-L overexpression caused delayed flowering in wild-type plants. Collectively, these results suggest regulation of HOS1 expression at the post-transcriptional level.

Specific Cutting Force Coefficients Modeling of End Milling by Using Neural Network (신경회로망을 이용한 엔드밀 가공의 비절삭력계수 모델링)

  • Lee, Sin-Young;Lee, Jang-Moo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.6 s.165
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    • pp.979-987
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    • 1999
  • In a high precision vertical machining center, the estimation of cutting forces is important for many reasons such as prediction of chatter vibration, surface roughness and so on, and cutting forces are difficult to predict because they are very complex and time variant. In order to predict the cutting forces of end-milling process for various cutting conditions, a mathematical model is important and this model is based on chip load, cutting geometry, and the relationship between cutting forces and chip loads. Specific cutting force coefficients of the model have been obtained as interpolation function types by averaging farces of cutting tests. In this paper, the coefficients are obtained by neural network and the results of the conventional method and those of the proposed method are compared. The results show that the neural network method gives more correct values than the function type and that in teaming stage as the omitted numbers of experimental data increases the average errors increase.

Improvement of electromigration characteristics in using Ai interlayer (Cu 배선에 Al층간 물질 첨가에 의한 EM특성 개선)

  • 이정환;박병남;최시영
    • Journal of the Korean Vacuum Society
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    • v.10 no.4
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    • pp.403-410
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    • 2001
  • Acceleration in integration density and speed performance of ULSI circuits require miniaturization of CMOS and interconnections as well as higher current density capabilities for transistors. A leading candidate to substitute Al-alloy is Cu, which has lower resistivity and higher melting point. So we can expect much higher electromigration resistance. In this paper, we are going to explain the major features of EM for MOCVD Cu according to variant conditions. We compared the life time and activation energy of MOCVD Cu with those of I-beam Cu and AA in the same conditions. The electromigration experiments were performed with Cu/Al/TiN multilayer. Experimental results shows that the deposition rate and electromigration characteristics of Cu thin film were improved by the Al interlayer.

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Quadratic GARCH Models: Introduction and Applications (이차형식 변동성 Q-GARCH 모형의 비교연구)

  • Park, Jin-A;Choi, Moon-Sun;Hwan, Sun-Young
    • The Korean Journal of Applied Statistics
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    • v.24 no.1
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    • pp.61-69
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    • 2011
  • In GARCH context, the conditional variance (or volatility) is of a quadratic function of the observation process. Examine standard ARCH/GARCH and their variant models in terms of quadratic formulations and it is interesting to note that most models in GARCH context have contained neither the first order term nor the interaction term. In this paper, we consider three models possessing the first order and/or interaction terms in the formulation of conditional variances, viz., quadratic GARCH, absolute value GARCH and bilinear GARCH processes. These models are investigated with a view to model comparisons and applications to financial time series in Korea

A study on the robust context-dependent acoustic models by considering the state splitting and the time variant of speech (음성의 시간변이와 상태분할을 고려한 강건한 문맥의존 음향모델에 관한 연구)

  • 오세진;김광동;노덕규;정현열
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04c
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    • pp.229-231
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    • 2003
  • 일반적으로 음성은 시간함수로 표현되며 음성인식에서 표준모델을 모델링하는 것은 매우 중요한 문제이다. 음절 단어, 연속음성을 발성할 때 자음과 모음에 따라 발성시간에 차이가 있으며 이를 잘 모델링하는 것 또한 음성인식에서는 중요한 문제라고 할 수 있다. 따라서 본 연구에서는 강건한 음향모델을 학습하기 위해 시간의 변화와 상태분할과정에서의 모델의 변화를 고려하여 다양한 구조의 초기모델을 작성하였다. 각 초기모델에 의한 HM-Net 문맥의존 음향모델은 음소결정트리 기반 SSS 알고리즘(PDT-SSS)을 이용하였다. PDT-SSS 알고리즘은 미지의 문맥정보를 해결하기 위해 문맥방향과 시간방향으로 목표 상태수에 도달할 때까지 상태분할을 수행하여 모델을 작성하는 방법이다. 음성의 시간변이를 고려한 강건한 문맥의존 음향모델을 작성하기 위해 설정한 각 모델의 구조에 대한 유효성을 확인하기 위해 국어공학센터의 452 단어를 대상으로 음소와 단어인식 실험을 수행한 결과. 음소인식의 경우 상태수 2000개에서 2상태 구조의 모델에 비해 4상태 구조가 약 11.4% 향상된 인식성능과 39.2초의 인식시간을 단축할 수 있었다. 또한 단어인식의 경우 상태수 2000개에서 1상태 구조의 모델에 비해 4상태 구조가 약 5% 향상된 인식성능과 4상태 구조에서 한 단어를 인식하는데 평균 0.8초가 소요되었다. 따라서 강건한 문맥의존 음향모델을 작성하기 위해 수행한 초기모델의 구조에 관한 연구가 향후 음성인식 시스템을 구축하는데 유효함을 확인할 수 있었다.

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Performance Improvement of SAR Autofocus Based on Partition Processing (분할처리 기반 SAR 자동초점 기법의 성능 개선)

  • Shin, Hee-Sub;Ok, Jae-Woo;Kim, Jin-Woo;Lee, Jae-Min
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.7
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    • pp.580-583
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    • 2017
  • To compensate the degraded SAR image due to the residual errors and the spatial variant errors remaining after the motion compensation in the airborne SAR, we have introduced the autofocus method based on the partition processing. Thus, after we perform the spatial partition for the spotlight SAR data and the time partition for the stripmap SAR data, we reconstruct the subpatch images for the partitioned data. Then, we perform the local autofocus with the suitability analysis process for the phase errors estimated by the autofocus. Moreover, if the estimated phase errors are not properly compensated for the subpatch images, we perform the phase compensation method with the weight to the estimated phase error close to the degraded subpatch image to increase the SAR image quality.