• Title/Summary/Keyword: floating solution

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A SHIPBOARD MULTISENSOR SOLUTION FOR THE DETECTON OF FAST MOVING SMALL SURFACE OBJECTS

  • Ko, Hanseok
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.174-177
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    • 1995
  • Detecting a small threat object either fast moving or floating on shallow water presents a formidable challenge to shipboard sensor systems, which must determine whether or not to launch defensive weapons in a timely manner. An integrated multisensor concept is envisioned wherein the combined use of active and passive sensor is employed for the detection of short duration targets in dense ocean surface clutter to maximize detection range. The objective is to develop multisensor integration techniques that operate on detection data prior to track formation while simultaneously fusing contacts to tracks. In the system concept, detections from a low grazing angle search radar render designations to a sensor-search infrared sensor for target classification which in turn designates an active electro-optical sensor for sector search and target verification.

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THREE-DIMENSIONAL INFINITE ELEMENTS FOR WAVE FORCE EVALUATION ON OFFSHORE STRUCTURES (해양구조물의 파력산정을 위한 3-차원 무한요소)

  • Park, Woo-Sun;Yoon, Chung-Bang;Pyun, Chong-Kun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1991.04a
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    • pp.8-14
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    • 1991
  • The finite element technique incorporating infinite elements is applied to analyzing the general three dimensional wave-structure interaction problems within the limits of linear wave theory. The hydrodynamic farces are assumed to be inertially dominated, and viscous effects are neglected. In order to analyze the corresponding boundary value problems efficiently, two types of elements are developed. One is the infinite element for modeling the radiation condition at infinity, and the other is the fictitious bottom boundary element for the case of deep water. To validate those elements, numerical analyses are performed for several floating structures. Comparisons with the results from culler available solution methods show that the present method incorporating tile infinite and the fictitious bottom boundary elements gives good results.

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Time-Domain Analysis on Motion Response of Adjacent Multiple-Bodies in Waves (파랑 중 근접한 다중 물체의 운동응답에 대한 시간영역 해석)

  • Kim, Kyong-Hwan;Kim, Yong-Hwan
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.1
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    • pp.63-72
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    • 2008
  • This study considers the motion response of multiple adjacent floating bodies in waves. As a method of solution, a three-dimensional Rankine panel method is adopted in time domain. For the validation of the developed numerical method, the motions of two adjacent Series 60 hulls and ship-barge model are estimated. The computational results are compared with other numerical and experimental analyses, showing favorable agreement.

Development of digital textile design using marbling dyeing technique and Photoshop for DTP (포토샵을 이용하여 공예적 기법인 마블링 패턴을 DTP 출력용 텍스타일 디자인으로 개발)

  • Kim, Sin-Hee
    • Journal of Fashion Business
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    • v.13 no.2
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    • pp.115-122
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    • 2009
  • Marbling dyeing technique shows beautiful flowing pattern because the pattern is transferred to the medium by the pigments floating onto the viscous solution base. However, this marbling pattern does not have any reproducibility and the result of accidental pattern formation. Marbling process contains many complicated procedures such as making marbling base, mordanting the medium, and bubble removal with size limitation. Computer changed the many aspects in textile design and digital technique is used in many design production. However, it is impossible to produce marbling pattern with digital drawing. In this research, the digital textile design starting from marbling pattern was developed for digital textile printing. Marbling was done to produce the initial motifs and scanned. Several marbling media such as silk, polyester, and paper were used. Photoshop was used to process and develop textile design based on these marbling motifs. One repeat was developed and various colorways were tried. The developed textile design were printed using DTP.

A fast adaptive numerical solver for nonseparable elliptic partial differential equations

  • Lee, June-Yub
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.2 no.1
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    • pp.27-39
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    • 1998
  • We describe a fast numerical method for non-separable elliptic equations in self-adjoin form on irregular adaptive domains. One of the most successful results in numerical PDE is developing rapid elliptic solvers for separable EPDEs, for example, Fourier transformation methods for Poisson problem on a square, however, it is known that there is no rapid elliptic solvers capable of solving a general nonseparable problems. It is the purpose of this paper to present an iterative solver for linear EPDEs in self-adjoint form. The scheme discussed in this paper solves a given non-separable equation using a sequence of solutions of Poisson equations, therefore, the most important key for such a method is having a good Poison solver. High performance is achieved by using a fast high-order adaptive Poisson solver which requires only about 500 floating point operations per gridpoint in order to obtain machine precision for both the computed solution and its partial derivatives. A few numerical examples have been presented.

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THE SIMPLICATION OF DYNAMICS FOR THE FLEXIBLE BODY (유연성을 갖는 매니퓰레이터 역학방정식의 간략화)

  • Park, Hwa-Sea;Bae, Jun-Kyung;Nam, Ho-Pub;Park, Chong-Kuk
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.950-953
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    • 1988
  • The equations of motion for linearly elastic bodies undergoing large displacement motion are derived. This produces a set of equations which are efficient to numerically integrate. The equations for the elastic bodies are formulated and simplified to provide as much efficiency as possible in their numerical solution. A futher efficiency is obtained through the use of floating reference frame. The equation are presented in two forms for numerical integration. 1) Explicit numerical integration 2) Implicit numerical integration. In this paper, there was used the numerical integration. The implicit numerical integration is extended to solved second order equation, futher reducing the numerical effort required. The formulation given is seen to be occulate and is expected to be efficient for many types of problems.

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Semi-resolution Practicability of Three-Dimensional Statics of Cables from Computer Programs

  • Dodaran, Asgar Ahadpour;Park, SangKil
    • Journal of Ocean Engineering and Technology
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    • v.26 no.6
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    • pp.1-6
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    • 2012
  • The purpose of this paper is to present a rational method for analyzing, designing, or evaluating the spread mooring systems used with floating drilling units. This paper presents a validated model to calculate the catenary static configuration. A semi-resolution approach is presented in this paper that is capable of predicting the static performance of a caisson mooring system. The solution is derived as a function of only three parameters, which can be solved numerically by implementing different kinds of boundary conditions. The efficiency and accuracy of the method permit quick parametric studies for the optimal selection of the system particle, which is undoubtedly useful for a preliminary design. A number of numerical examples demonstrate the validity of the adopted approach. The paper contains a complete description of the test cases and reports the results in such a way that it can provide a "benchmark" test for users and programmers of computer codes for flexible riser analysis.

Development of Highly Stable Organic Nonvolatile Memory

  • Baeg, Kang-Jun;Kim, Dong-Yu;You, In-Kyu;Noh, Yong-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.904-906
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    • 2009
  • Organic field-effect transistor (OFET) memory is an emerging device for its potential to realize light-weight, low cost flexible charge storage media. Here we report on a solution-processed poly[9,9-dioctylfluorenyl-2,7-diyl]-co-(bithiophene)] (F8T2) nano floating-gate memory (NFGM) with top-gate/bottom-contact device configuration. A reversible shift in the threshold voltage ($V_{Th}$) and the reliable memory characteristics were achieved by incorporation of thin Au nanoparticles (NPs) as charge storage sites for negative electrons at the interface between polystyrene and cross-linked poly(4-vinylphenol).

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Tornado-Induced Extreme Waves in an Offshore Basin Revisited (토네이도가 유발한 막대한 파에 대한 재고)

  • Yong Kwon Chung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.10 no.3
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    • pp.120-124
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    • 1998
  • The present study was initiated to protect floating nuclear power plants from the tornado. The solution shows that a tonado induces extreme waves of 27 ft (8.2 m) in height if it crosses the basin with a speed close to the critical speed. Waves generated by wind stress are ignored.

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Numerical Study on the Local Motion of an A-frame for Deep Sea ROV Mother Ship in Irregular Waves (심해잠수정 모선의 A-프레임 시간영역 국부운동해석)

  • Hong, Do-Chun;Lee, Pan-Mook
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.105-108
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    • 2003
  • The local motion at the top of an A-frame fixed on a research vessel for deep sea ROV floating in irregular waves is studied in the time-domain. The motion is analyzed in the time-domain using the convolution integral of the radiation forces. The memory effect functions and infinite frequency added masses are obtained from the solution of the three dimensional improved Green integral equation in the frequency domain by making use of the Fourier transformation.

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