• Title/Summary/Keyword: 전복해석

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Analysis on the Dynamic Responses of Fishing Vessels in a Seaway (파랑중 어선의 동력학 해석)

  • 이희상
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.1
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    • pp.33-44
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    • 2000
  • Ships in a seaway will encounter dangerous situation, such as slamming, stranding, and capsizing. The number of capsizing is small, but the loss due to them is very large from the viewpoint of human life, property, and the environmental pollution. The number of capsizing of fishing vessels is about 62% of total number of capsizing, and the half of them is originated from the operational mistake in a seaway. So the dynamics and the capsizing phenomena are to be studied, and the guide for the safe operation of a fishing vessel in a seaway are to be specified. The hydrodynamic forces consist of radiation forces (which are due to the motion of a ship), Froude-Krylov forces (which is due to the incoming waves), and diffraction forces (which is due to the wave and ship interaction). These forces are calculated by well-known strip method. Using the calculated forces, the motion of a ship in a regular sea is obtained. In the real seaway, the waves are very irregular, therefore the statistical analysis is very helpful. In this paper, using the results of the motion in a regular seaway and the wave spectrum, the motion in a irregular seaway are obtained and analyzed.

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Structural Design and Analysis of a Hydraulic Coiling Arm for Offshore Wind-turbine Submarine Cable (해상풍력 해저케이블 하역용 유압식 코일링 암 구조설계 및 해석)

  • Kim, Myung-Hwan;Kim, Dong-Hyun;Oh, Min-Woo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.1-7
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    • 2013
  • Structural design and analysis of a coiling arm unloading machine for submarine cable have been originally conducted in this study. Three-dimensional CAD modeling process is practically applied for the structural design in detail. Finite element method(FEM) and multi-body dynamics(MBD) analyses are also used to verify the safety and required motions of the designed coiling arm structure. The effective moving functions of the designed coiling arm with respect to rotational and radial motions are achieved by adopting bearing-roller mechanical parts and hydraulic system. Critical design loading conditions due to its self weight, carrying cables, offshore wind, and hydraulic system over operation conditions are considered for the present structural analyses. In addition, possible inclined ground conditions for the installation of the designed coiling arm are also considered to verify overturn stability. The present hydraulic type coiling arm system is originally designed and developed in this study. The developed coiling arm has been installed at a harbor, successfully tested its operational functions, and finished practical unloading mission of the submarine cable.

Reading Luces de Bohemia with Carnivalism (카니발리즘으로 읽는 『보헤미아의 빛』)

  • Kim, Seon-Uk
    • Iberoamérica
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    • v.21 no.2
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    • pp.25-52
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    • 2019
  • Esperpento denotes a literary style in Spanish literature first established by Spanish author Ramón María del Valle Inclán that uses distorted descriptions of reality in order to criticize society. And esperpento's narrative strategy is similar in many ways to Mikhail Bakhtin's carnivalism. Especially Valle Inclán's first esperpentic theatre, Luces de Bohemia contained various carnivalistic elements of Bakhtin. The various techniques of Valle Inclán's esperpento used in Luces de Bohemia can be explained by Bachchin's carnivalist techniques. Therefore, this paper aims to re-examine the esperpentic techniques in Luces de Bohemia of Valle Inclán in terms of Bakhchin's carnivalism. Because the esperpentic tecniques of this play pursue the subversion of power or authority through the carnivalistic aspects such as polyphony, subversion of seriousness, parody, grotesque realism, plaza, ambivalence, anomalous structure of space, time and plot, etc. Esperpento and carnivalism serve as a tool to interpret the social reality, beyond criticism and satire of Spanish society. The characters act passively on all the external factors that determine human destiny, rather than actively carving their own destiny like the classic heroes. Modern man cannot defy or control the external situation of the modern civilization. So they are tragic. In this situation, the protagonist of the tragedy who challenges reality disappears and a puppet figure like Max Estrella, the protagonist of the Luces de Bohemia, takes his place on a satirical level. This is the satire and the true meaning of carnivalistic humor that Valle Inclán tried in his play.

A Study on Viscous Damping System of a Ship with Anti-Rolling Pendulum (안티롤링 진자를 장치한 선박의 점성감쇠계 해석에 대한 연구)

  • Park, Sok-Chu;Jang, Kwang-Ho;Yi, Geum-Joo
    • Journal of Navigation and Port Research
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    • v.41 no.6
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    • pp.365-372
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    • 2017
  • The rolling motion of a floating body makes crews and passengers exhausted and/or applies forces to the structure to cause damage; it might even upset the body. Therefore, almost all ships are equipped with bilge keels for anti-rolling; in special cases, an anti-rolling tank(ART) or fin stabilizer or gyroscope could be installed. But an ART requires a large capacity to install it, and a fin stabilizer and gyroscope need great costs to install and also many expenses to operate. The authors suggest the use of an anti-rolling pendulum(ARP), and they showed that the ARP is effective to reduce rolling by experiments and via a Runge-Kutta analysis. This paper introduces the linearized 2 degrees of freedom with a viscous damping system for a ship equipped with ARP; it also shows the validation of the linearized analysis for the ship's roll motion. The paper proposes an optimum ARP on the basis of the justified model. The case of the 7.7kg model with ship 20g ARP of a mass ratio of 0.26%, is the most effective for reducing roll motion. The paper shows the ARPs with various mass ratios are effective for reducing the roll motion of a ship by free decaying roll experiments.

The Study on Elementary Male and Female Students' Abilities to Construct and Interpret Graphs Based on Their Spatial Abilities and Science Process Skills (초등학교 남.녀 학생들의 공간 능력 및 과학 탐구 능력에 따른 그래프 작성 및 해석 능력에 관한 연구)

  • Jeon, Bok-Hee;Lee, Hyeong Cheol
    • Journal of Korean Elementary Science Education
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    • v.31 no.4
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    • pp.490-500
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    • 2012
  • This study was to examine elementary male and female students' spatial abilities, science process skills, and graph construction and interpretation abilities in order to understand the effect that their spatial abilities and science process skills would have on their graph abilities. To conduct this study, total 12 classes of 435 pupils, 6 classes each from grades 5 and 6 in elementary schools were selected for subjects. The number of male student was 207 and that of female one was 228 of them. And previous test papers of spatial abilities, of science process abilities, and of graph abilities were retouched and updated for reuse in new tests. The results of this study are briefed as follows: Firstly, when spatial abilities for male and female group were compared, female group showed a little higher rate of correct answering than male, but not providing statistically significant gap. Secondly, the science process skill tests revealed basic process skills of both groups were more excellent than their integrated process skills, while female group was found to have more correct answers than male, all of which were proving statistical distinction. Thirdly, of graphing skills for two groups, the graph interpretation skills turned out to be better than the graph construction skills, with female group scoring higher than male and with meaningful difference. Fourthly, both between spatial abilities and graph abilities, and between science process skills and graph abilities, static correlations existed with statistical meaning. In other words, those with higher spatial abilities or science process skills were to do better in constructing and interpreting graphs.

Experimental Study on the Deck Wetting of a Container Ship in Irregular Head Waves (콘테이너선의 불규칙파중 갑판침수에 관한 실험적 고찰)

  • Sa-Young,Hong;Pan-Mook,Lee;Do-Sig,Gong
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.2
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    • pp.31-39
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    • 1990
  • Deck wetness phonomena has long been considered as one of the factors that degrade the performance of a ship in waves. In rough weather, the frequent shipping of water may give rise to the capsizing of the ship. Therefore an appropriate above water bow design is an improtant assert to a ship of which successful performance in rough weather is a prerequisite such as a warship. In this paper the experimental technique for estimation of deck wetness frequency is presented. The results of the model tests are compared with those of calculation using Ochi's formula. Finally the applicability of Ochi's formula is discussed.

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Shape Optimization of a Hole for Water Jetting in a Spudcan for a Jack-up Rig (잭업리그 스퍼드캔의 물 분사용 홀 형상 최적화)

  • Seong, Jeong Hyeon;Han, Dong Seop;Park, Young Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.4
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    • pp.337-342
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    • 2016
  • A spudcan is mounted on the lower leg of the jack-up rig, a device for preventing a rollover of a structure and to support the structure in a stable sea floor. At the time of inserting the surface of the spud can to penetrate when the sand layer is stable and smoothly pulled to the clay layer, and at that time of recovery when uploading the spud can is equipped with a water injection device. In this study, it is significant to optimize the shape of pipelines holes for water injection device and it was set in two kinds of shape, the oval and round. Interpretation of the subject into the site of Gulf of Mexico offshore Wind Turbine Installation Vessels (WTIV) was chosen as a target platform. Using the ANSYS Workbench commercial programs, optimal design was conducted. The results of this study can be applied to the hole-shaped design of various marine structures.

Enacting enactivism: Concerning the translation problem (Enactivism을 Enact하기: 번역의 문제를 중심으로)

  • Bae, Moon-Jung
    • Korean Journal of Cognitive Science
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    • v.25 no.4
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    • pp.303-341
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    • 2014
  • Enactivism is the most influential and groundbreaking approach among the various theories of embodied cognition. Despite of it's impact and relatively long history, however, Enactivism is still considered as a new and unfamiliar theory in the Korean academic society. Even though this might be partly due to the genuine depth and dramatic approach of Enactivism, it is also due to the disagreement of Korean translation of Enactivism. This paper reviews the philosophical and theoretical implications of Enactivism in the context of history and conceptual terrain, and discusses how the various tranlated Korean words of 'Enaction' - '발제(發製)' '구성(構成)', or '행위화(行爲化)'- embraced and interpreted the essence of philosophy and concept of 'Enaction' and 'Enactivism'. Furthermore, we offer several alternatives Korean translations of 'Enaction': '실행(實行)', 수행(遂行/修行), or 작동(作動). Through this discussion, we hope to provide an opportunity for Korean researchers and philosophers to direct their attention to Enactivism properly and to make a common ground for further development of Enactivism in Korea.

Multivariate Data Analysis on Marine Casualties (다변량해석법(多變量解析法)에 의한 해난사고(海難事故)의 분석(分析))

  • Kim, Yeong-Sik;Kim, Jeong-Chang
    • Journal of Fisheries and Marine Sciences Education
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    • v.6 no.2
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    • pp.190-197
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    • 1994
  • In this paper, 2513 marine casualties occurred in Korean waters, during 1989-1993, were analysed by the Multivariate Data Analysis Method. The main results obtained were as follows : 1. Moat of marine casualties resulted from the human factors such as careless operation and insufficient engine maintenance. Engine trouble accounted for main patten of accidents and great number of accidents occurred in fishing vessels. 2. From the point of view of the damage of human life and properties, accidents took place in cargo ships, passenger ships and tankers were serious, but in fishing vessels, those were not so serious. 3. Grounding, collision mainly resulted from careless operation, however flooding and capsizing were much affected by bad weather and material defect.

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Analysis of Load Simulating System Considering Lateral Behavior of a Vehicle (횡방향 거동 특성을 고려한 부하모사 시스템 해석)

  • Kim, Hyo-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.621-626
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    • 2019
  • The driver's steering wheel maneuver is a typical disturbance that causes excessive body motion and traveling instability of a vehicle. Abrupt and extreme operation can cause rollover depending on the geometric and dynamic characteristics, e.g., SUV vehicles. In this study, to cope with the performance limitation of conventional cars, fundamental research on the structurization of a control system was performed as follows. Mathematical modeling of the lateral behavior induced by driver input was carried out. A controller was designed to reduce the body motion based on this model. An algorithm was applied to secure robust control performance against modeling errors due to parameter uncertainty, $H_{\infty}$. Using the decoupled 1/4 car, a dynamic load simulating model considering the body moment was suggested. The simulation result showed the validity of the load-simulating model. The framework for a lateral behavior control system is proposed, including an experimental 1/4 vehicle unit, load simulating module, suspension control module, and hardware-in-the-loop simulation technology.