• Title/Summary/Keyword: independent segment

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Investigation on the integrated transfer function characteristics for the buffeting response prediction of elongated structures

  • Yi Su;Mingshui Li;Jin Di;Yang Yang;Shaopeng Li
    • Wind and Structures
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    • v.37 no.6
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    • pp.399-412
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    • 2023
  • Previous studies have shown that the integrated transfer function (ITF) is independent of turbulence characteristics and can be effectively applied to predict the buffeting response of elongated structures, assuming that the strip hypothesis is valid. However, existing research has not effectively identified the ITF through segment model vibration tests, and the influence of the 3D effect on the accuracy of the strip hypothesis and the characteristics of the ITF in wind tunnel tests has not been quantitatively studied. A segment model vibration measurement device that can change a test model's span-width ratio was designed in this study. An airfoil section and a streamlined box girder section structure were taken as the background, and their ITFs were effectively identified under different L/B (L denotes the turbulent integral scale and B denotes the structural width) and model span-width ratios. The influence laws of the 3D effect on the accuracy of the strip hypothesis and ITF identification in wind tunnel tests were systematically investigated. The results showed that L/B and the structural span-width ratio are two significant controlling factors that affect the accuracy of the strip hypothesis and ITF identification. The research provides an effective experimental method for accurately predicting the buffeting response of elongated structures based on ITFs identified through segment model vibration tests.

A Basic Study on the Maritime Performing Party System and the Difference between the Maritime System and China's system

  • Liu, Xiaoxian;Noh, Chang-Kyun
    • Journal of Navigation and Port Research
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    • v.36 no.4
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    • pp.299-303
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    • 2012
  • "United Nations Convention on Contracts for the International Carriage of Goods Wholly or Partly by Sea" was passed in July 3, 2008. on September 23, 2009 signing ceremony was held in Rotterdam. The system of maritime performing party is a special system in the transport convention, and constitutes an integral part of the Convention. Maritime performing party system is not the first system which brings in the carrier's independent contractor, but it is the most comprehensive and thorough one. It unified the duty of carrier's independent contractor in the maritime segment, and it is also an important progress in the developing process of international maritime legal system. There are some differences between the maritime performing party and China's current related system, i.e, the port maritime performing party and the intermediate performing party are included in the maritime performing party, and they can enjoy the carrier's exception clause and limitation of liability.

Developmental and Environmental Sources of Variation on Annual Growth Increments of Ascophyllum nodosum (Phaeophyceae)

  • Eckersley, Lindsay K.;Garbary, David J.
    • ALGAE
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    • v.22 no.2
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    • pp.107-116
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    • 2007
  • Annual growth segments of Ascophyllum nodosum (L.) Le Jolis (Fucales, Fucaceae) are denoted by air bladders that form each spring. By examining annual growth segments, it may be possible to infer information about the physical conditions during the growth period; however, it is uncertain whether the annual segments will expand in size after the initial growth. We examined A. nodosum segments from three populations in Nova Scotia, and statistically evaluated whether the annual growth (length, mass, and maximum diameter) of segments was independent of the age of the frond, whether the segments increased in size after the initial growth, and whether the segment lengths were correlated with mean water temperatures and mean air temperatures when the segments were formed. We found that the growth in length of A. nodosum is dependent on the age of the frond, but frond age explained less than 12 % of the overall variation in length. However, the mass and maximum diameter of segments were independent of the age of the frond. Differences occurred between the lengths of segments formed in different years, but there was no significant correlation with regional mean water or air temperatures. This study indicates that the length of A. nodosum segments may be an indicator of the annual physical characteristics of a site, but future studies are needed to identify which factors have the strongest influence on growth patterns.

Human Postural Response to Linear Perturbation (선형외란에 대응하는 인체의 자세응답 해석)

  • Kim, Se-Young;Park, Su-Kyung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.1
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    • pp.27-33
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    • 2009
  • Human postural responses appeared to have stereotyped modality, such as ankle mode, knee mode and hip mode in response to various perturbations. We examined whether human postural control gain of full-state feedback could be decoupled along with the eigenvector. To verify the model, postural responses subjected to fast backward perturbation were used. Upright posture was modeled as 3-segment inverted pendulum incorporated with feedback control, and joint torques were calculated using inverse dynamics. Postural modalities such as ankle, knee and hip mode were obtained from eigenvectors of biomechanical model. As oppose to the full-state feedback control, independent eigenvector control assumes that modal control input is determined by the linear combination of corresponding modality. We used optimization method to obtain and compare the feedback gains for both independent eigenvector control and full-state feedback control. As a result, we found that simulation result of eigenvector feedback was not competitive in comparison with that of full-state feedback control. This implies that the CNS would make use of full-state body information to generate compensative joint torques.

The Effects of Visible Light on Iron Release from Ferritin Related to Lipid Peroxidation in the Retina

  • Ohishi, Kentaro;Hiramitsu, Tadahisa;Matsugo, Seiichi
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.427-429
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    • 2002
  • We studied iron release from ferritin by irradiating the visible light, and then followed ferritin-mediated lipid peroxidation in the rod outer segment (ROS) fraction of the porcine retina. In the presence of several phosphorus compounds such as ADP and ATP, iron release from ferritin at pH 7.0 could be induced by irradiation of the visible light to the reaction mixtures. Furthermore, iron release from ferritin in the presence of ADP depended on the incubation time and the visible light irradiation. Moreover, we investigated lipid peroxidation level in the ROS fraction by two independent assay systems including the thiobarbituric acid (TBA) and ferrous oxidation/xylenol orange (FOX) methods. The visible light induced ferritin-mediated lipid peroxidation in the ROS fraction in time- and irradiance-dependent manners. In the dark condition, iron release and lipid peroxidation were not observed. Iron release from ferritin by irradiating the visible light may play an important role in the etiology of phototoxic injuries in vivo.

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Static Walking Algorithm for a Quadruped Robot using Tilting (틸팅을 이용한 4족 보행 로봇의 정적 보행 알고리즘)

  • Lee, Sun-Geol;Jo, Chang-Hyeon;Kim, Byeong-Su
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.8
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    • pp.675-679
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    • 2001
  • This paper presents walking algorithm for a quadruped robot that does not have an upper body. Tilting motion is added to the planned walking trajectory instead of using an extra body segment that is independent on walking trajectory. Area and tracking algorithms are proposed as tilting method and compared with that of off-line tilting and that of no tilting. Computer simulation shows that stability of tilted walking is more improved than that of the usual walking algorithm for general walking paths. It also shows that the tracking method guarantees stability and best mobility.

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A Modular Decomposition Model for Software Project Scheduling

  • Kim, Kiseog;Nag, Barin N.
    • Journal of the Korean Operations Research and Management Science Society
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    • v.18 no.3
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    • pp.129-149
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    • 1993
  • The high level of activity in the development and maintenance of computer software makes the scheduling of software projects an importnat factor in reducing operating costs and increasing competitiveness. Software activity is labor intensive. Scheduling management of hours of software work is complicated by ther interdependencies between the segments of work, and the uncertainties of the work itself. This paper discusses issues of scheduling in software engineering management, and presents a modular decomposition model for software project scheduling, taking advantage of the facility for decomposition of a software project into relatively independent work segment modules. Modular decomposition makes it possible to treat scheduling as clustering and sequencing in the context of integer programming. A heuristic algorithm for the model is presented with some computational experiments.

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Iterative learning control of robot manipulators (로봇 매니퓰레이터의 반복 학습 제어)

  • 문정호;도태용;정명진
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.470-473
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    • 1996
  • This paper presents an iterative learning control scheme for industrial manipulators. Based upon the frequency-domain analysis, the input update law of the learning controller is given together with a sufficient condition for the convergence of the iterative process in the frequency domain. The proposed learning control scheme is structurally simple and computationally efficient since it is independent joint control depending only on locally measured variables and it does not involve the computation of complicated nonlinear manipulator dynamics. Moreover, it is capable of canceling the unmodeled dynamics of the manipulator without even the parametric model. Several important aspects of the learning scheme inherent in the frequency-domain design are discussed and the control performance is demonstrated through computer simulations.

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CT HEAD IMAGES SEGMENTATION USING UNSUPERVISED TECHNIQUES

  • Lee, Tong Hau;Fauzi, Mohammad Faizal Ahmad;Komiya, Ryoichi;Hu, Ng
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.217-222
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    • 2009
  • In this paper, a new approach is proposed for the segmentation of Computed Tomography (CT) head images. The approach consists of two-stage segmentation with each stage contains two different segmentation techniques. The ultimate aim is to segment the CT head images into three classes which are abnormalities, cerebrospinal fluid (CSF) and brain matter. For the first stage segmentation, k-means and fuzzy c-means (FCM) segmentation are implemented in order to acquire the abnormalities. Whereas for the second stage segmentation, modified FCM with population-diameter independent (PDI) and expectation-maximization (EM) segmentation are adopted to obtain the CSF and brain matter. The experimental results have demonstrated that the proposed system is feasible and achieve satisfactory results.

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A Study on Feature Hierarchy in English (영어의 자질 수형도에 관한 연굴)

  • Lee Hae-Bong
    • MALSORI
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    • no.29_30
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    • pp.43-60
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    • 1995
  • Standard generative phonologists assumed that there were no orders or hierarchies among distinctive features. This means that the distinctive features which make up a segment are independent and unordered. The unordered linear matrix cannot explain phonological phenomena such as complex segments as hierarchical representation does neatly. The hierarchical feature representation theory which embodies the concept of multi-tiered phonological representation organizes distinctive features in the appearance of hierarchical dominance. This paper aims to show how we can solve some problems of the linear feature representation. As regard underlying representation the theory of underspecification is discussed. I propose a feature hierarchy similar to that of Sagey(1986) but slightly different. I show English consonantal assimilation in feature hierarchical model compared with that of feature changing theory of linear representation.

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