• Title/Summary/Keyword: Udo

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Transfer function approximation of motion-induced aerodynamic forces with rational functions

  • Kirch, Arno;Peil, Udo
    • Wind and Structures
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    • v.14 no.2
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    • pp.133-151
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    • 2011
  • For a detailed investigation of the dynamic behaviour of slender bridges under wind action especially the motion-induced fluid forces should be available not only for harmonic motions but also for more general ones. If linear transfer behaviour is assumed, the force-displacement relation for almost arbitrary motions can be handled in the frequency domain using aerodynamic transfer functions. In aerospace engineering as well as in bridge engineering, these functions are usually approximated by special kinds of complex-valued rational functions which depend on complex frequencies. The quality of this approximation is evaluated for several bridge cross sections in this article. It is shown that rational functions are for some sections scarcely suitable to realistically represent the transfer behaviour of motion-induced aerodynamic forces for arbitrarily complex frequencies.

Polyvinyl butyral DMN-conjugates for the controlled release of singlet oxygen in medical and antimicrobial applications

  • Posavec, Damir;Muller, Rainer;Bogner, Udo;Bernhardt, Gunther;Knor, Gunther
    • Biomaterials and Biomechanics in Bioengineering
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    • v.1 no.2
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    • pp.73-79
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    • 2014
  • Covalent attachment of 1, 4-dimethylnaphthalene (DMN) based endoperoxide forming subunits to a polyvinyl butyral (PVB) backbone has been achieved. The functionalized polymer materials prepared and characterized here can serve as biocompatible carrier systems for studying cellular uptake, intermediate storage and delayed release of singlet oxygen, which opens up new doors for optimizing a variety of medical applications of photogenerated DMN-endoperoxides such as antiviral, antibacterial, antiplasmodial and antitumor activity.

Miuraea migitae, a new record of the order Bangiales (Bangiophyceae, Rhodophyta) from Korea

  • Koh, Young Ho;Lee, Hyung Woo;Kim, Myung Sook
    • Fisheries and Aquatic Sciences
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    • v.19 no.9
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    • pp.38.1-38.5
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    • 2016
  • We found specimens of foliose Bangiales from the subtidal zone of Udo, Jeju Island, Korea. In molecular analyses of rbcL sequences, these Korean specimens were almost identical to Miuraea migitae from Osaka, Japan. In the morphological comparison, Korean specimens were consistent with habitat, color, and vegetative characteristics with the description of M. migitae. This is the first record of M. migitae outside the type locality and Nagasaki in Japan. This study confirms that new or unrecorded species of the order Bangiales may be discovered from subtidal habitats.

SUBSISTENCE FARMERS' ACCESS TO CATTLE VIA SHARING IN UPLAND FARMING SYSTEMS IN EAST JAVA, INDONESIA

  • Ifar, S.;Solichin, A.W.;Udo, H.M.J.;Zemmelink, G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.2
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    • pp.215-221
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    • 1996
  • In the marginal upland areas of East Java, Indonesia, ruminants provide farming households with tradable assets in addition to manure and draught power. Households are interested in acquiring ruminants at an early stage of household development. This paper discusses farmers' access to cattle via sharing arrangements. In these arrangements owners lend animals to other farmers in retum for a share of the offspring or the profits. Livestock owners only entrust cattle to households with prior experience in livestock keeping and sufficient labour. Details of the sharing contracts differ between villages. Changes in cattle numbers and ownership over time are attributed to patterns of the development of village agriculture and the economic development of farming households. Feed shortages in the dry season bring about short-term changes; cattle numbers decline and the proportion of households rearing shared cattle increases. The institution of sharing plays a major role in replenishing herds after periods of severe drought.

A Systematic Study on the Holothuroidea in Choju-do

  • Park, Boon-Jo;Sook Shin
    • The Korean Journal of Zoology
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    • v.29 no.4
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    • pp.245-260
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    • 1986
  • For the systematics study of the Holothuroidea in Cheju-do the present study was done with the materials collected from seven localities of Cheju-to (Cheju-hang, Piyangdo, Hallim, Sogwip'o, Tangp'o Songsanp'o, Udo) during the period from December 1969 to February 1986. As a result the holothurians in Cheju-do consit of nine species, six families, three orders and three subclasses. Of those five species are reported for the first time from Korean waters and they are as follows: Holothuria monacaria, H. pardalis, Afrocucumis africana, Leptosynapta ooplax and Polycheira rufescens.

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Modeling of rain-wind induced vibrations

  • Peil, Udo;Nahrath, Niklas
    • Wind and Structures
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    • v.6 no.1
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    • pp.41-52
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    • 2003
  • Rain-wind induced vibrations of cables are a challenging problem in the design of cable-stayed bridges. The precise excitation mechanism of the complex interaction between structure, wind and rain is still unknown. A theoretical model that is able to accurately simulate the observed phenomena is not available. This paper presents a mathematical model describing rain-wind induced vibrations as movement-induced vibrations using the quasi-steady strip theory. Both, the vibrations of the cable and the movement of the water rivulet on the cable surface can be described by the model including all geometrical and physical nonlinearities. The analysis using the stability and bifurcation theory shows that the model is capable of simulating the basic phenomena of the vibrations, such as dependence of wind velocity and cable damping. The results agree well with field data and wind tunnel tests. An extensive experimental study is currently performed to calibrate the parameters of the model.

Limitations for the control of wind-loaded slender bridges with movable flaps

  • Kirch, Arno;Peil, Udo
    • Wind and Structures
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    • v.15 no.5
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    • pp.441-462
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    • 2012
  • This article presents theoretical investigations on techniques for the improvement of the dynamic characteristics of slender bridges under wind action. Aerodynamically effective control shields are applied as controlled actuators. The first part of the article describes the modelling of the uncontrolled aeroelastic system. Acting aerodynamic forces are consistently characterised using linear time-invariant transfer elements in terms of rational functions. On this basis, two configuration levels of the uncontrolled system are represented with linear time-invariant state-space models and investigated. The second part of the article addresses controller design and the behaviour of the controlled aeroelastic system. Both fundamental limits for stabilisation and the efficiency for attenuating the influence of gusts are described for different actuator mechanisms. The results are derived and discussed with methods of control theory.

The Effect of Displaying Products in Their Usage Context - A Field Experimental Investigation -

  • Claus, Ebster;Wagner, Udo;Auzinger, Cora
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.2
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    • pp.99-110
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    • 2007
  • The widespread use of self-service concepts in retailing has resulted in increased attention to the design of retail environments and to stimuli operating at the point of sale. One such merchandising technique, the "bundled presentation", i.e., related products are presented in close proximity to each other, is widely used by retailers but has rarely been investigated by academic consumer researchers. This study presents the results of a field experiment into the effects of presenting products in their usage context. Customers' attitudes towards the same product displayed in different ways are compared with each other. The results show that related products, i.e., products that are used together, should be presented in a coordinated display. Furthermore, the bundled presentation enhanced consumers' attitudes of the product when they saw it first in a bundled presentation and then evaluated it in front of a traditional presentation.

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독일 해군의 차세대 212급 잠수함

  • Lee, Gi-Seon
    • Defense and Technology
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    • no.7 s.233
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    • pp.60-69
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    • 1998
  • 독일 HDW조선소의 Bonn 지사장으로 근무중인 Udo Ude씨는 209급 잠수함 해외수출 성공사례를 다음과 같이 분석하였다. -1970년 독일해군용 206급 계약시 잠수함을 해군에 인도하기 전까지의 모든 과정을 조선소가 직접 책임지고 수행토록 하는 General Contractor Principle(총괄계약자 원칙)에 의해 확보된 기술인력, 자재/장비 공급원 발굴, 축적된 장비간 연동과 체계통합 기술 및 경험 –대부분의 탑재 장비를 국내 방산업체로부터 조달할 수 있는 탄탄한 국내 기술력 –매 신규사업마다 성능향상을 위한 과제선정 및 계속적인 연구 –정부 소유 시험시설 및 장비 활용과 제반 기술관리에 있어서 민.관.군의 적극적이고 긴밀한 지원체제 구축 이러한 성공사례 분석에 독일 현지에서 느낀 필자의 경험소감을 추가하면 다음과 같다. –규정을 잘 지킬 뿐만 아니라 타인의 잘못을 즉시 일깨워 주는 준법정신 및 고발정신 -2-3년 후의 휴가계획까지 수립하여 준비할 정도의 처절한 사전계획 및 준비정신 –불결한 것과 게으름을 참지 못하는 청결성 및 근면성 –누구든지 원하면 경제적인 부담없이 평생동안 공부할 수 있는 교육제도 –게르만족이 우월하다는 내면적 자부심 –작은 일이라도 모여서 토의하고 결론을 도출하기 좋아하는 공동체 의식 –약속을 철저히 지키는 정직성 –과거의 사실이나 유물을 철저히 보존하는 역사의식 –모든 분야에서 철저하게 운용되는 Meister(장인)제도 등

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The Janus Concept -A Completely New Calendering Technology to Meet Future Market Requirements

  • Gabbusch, Udo
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.29 no.3
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    • pp.82-86
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    • 1997
  • At Present, high-quality paper finishes are obtained by the exclusive un of supercalenders and softcalenders. Experience has shown that both calendering processes will not always k able to meet future requirements of increased efficiency combined with improved paper finish. The answer to these challenges is the development of a new technology, a synergy of supercalender and soft-calender called the “Janus concept”. This paper outlines the rationale behind this new development as well in the technical characteristics providing for the successful online integration irrespective of production speed. Laboratory results are included ta demonstrate that the Janus Concept enables a high-quality SC finish even at PM or CM speeds.

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