• Title/Summary/Keyword: Anchor system

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Enhancing the Awareness of Decentralized Cooperative Mobile Robots through Active Perceptual Anchoring

  • Guirnaldo, Sherwin A.;Watanabe, Keigo;Izumi, Kiyotaka
    • International Journal of Control, Automation, and Systems
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    • v.2 no.4
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    • pp.450-462
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    • 2004
  • In this paper, we describe a system for controlling the perceptual processes of two cooperative mobile robots that addresses the issue of enhancing perceptual awareness. We define awareness here as knowing the location of other robots in the environment. The proposed system benefits from a formalism called perceptual anchoring. Here, perceptual anchoring enhances the awareness of the system by employing an anchor-based active gaze control strategy or active perceptual anchoring to control the perceptual effort according to what is important at a given time. By anchoring we extend the notion of awareness as knowing what the symbols in the control module represent to by connecting them to the objects or features in the environment. We demonstrate the present system through a simulation of two nonholonomic mobile robots performing a cooperative transportation by carrying a cargo to a target location where there are two other robots moving about. The system is able to efficiently focus the perceptual effort and thus able to safely carry the cargo to the target position.

Experimental evaluation of the active tension bolt

  • Kim, Sang-Hwan;Song, Ki-Il;Park, Jae-Hyun
    • Geomechanics and Engineering
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    • v.11 no.2
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    • pp.177-195
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    • 2016
  • To secure the stability of geotechnical infrastructures and minimize failures during the construction process, a number of support systems have been introduced in the last several decades. In particular, stabilization methods using steel bars have been widely used in the field of geotechnical engineering. Rock bolt system is representative support system using steel bars. Pre-stressing has been applied to enhance reinforcement performance but can be released because of the failure of head or anchor sections. To overcome this deficiency, this paper proposes an innovative support system that can actively reinforce the weak ground along the whole structural element by introducing an active tension bolt containing a spring unit to the middle of the steel bar to increase its reinforcement capacity. In addition, the paper presents the support mechanism of the active tension bolt based on a theoretical study and employs an experimental study to validate the performance of the proposed active tension bolt based on a down-scaled model. To examine the feasibility of the active tension unit in a pillar, the paper considers a pullout test and a small-scale experimental model. The experimental results suggest the active tension bolt to be an effective support system for pillar reinforcement.

Experimental Results of Ship-to-Ship Stabilized Mooring System for Mobile Harbor

  • Jeong, Tae-Gweon;Lee, Yun-Sok;Chen, Chao;Kim, Se-Won
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2010.04a
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    • pp.219-220
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    • 2010
  • A new concept of ocean transport system, called mobile harbor, was introduced as a feasibility study in Korea in 2009. Target of the mobile harbor is a smart distance transport of containers with or without cargo handling cranes. Although the mobile harbor project has a lot of topics to deal with, this paper is to focus on only ship-to-ship stabilized mooring, which plays a key role in cargo handling. The ship-to-ship stabilized mooring system was developed and installed on beard a barge of LOA 32m and breadth 12m. The dockside tests as sea test were carried out so as to ascertain ascertained whether the systems can work well to control the barge's motion. The results of dockside test showed that the heave motion of the barge's motion can be reduced by more than 45%.

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Experimental Results of Ship-to-ship Stabilized Mooring System for Mobile Harbor

  • Jeong, Tae-Gweon;Lee, Yun-Sok;Chen, Chao;Kim, Se-Won
    • Journal of Navigation and Port Research
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    • v.34 no.4
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    • pp.281-286
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    • 2010
  • A new concept of ocean transport system, called mobile harbor, was introduced as a feasibility study in Korea in 2009. Target of the mobile harbor is a short distance transport of containers with or without cargo handling cranes. Although the mobile harbor project has a lot of topics to deal with, this paper is to focus on only ship-to-ship stabilized mooring, which plays a key role in cargo handling. The ship-to-ship stabilized mooring system was developed and installed on board a barge of LOA 32m and breadth 12m. The dockside tests as sea test were carried out so as to ascertain whether the systems can work well to control the barge’s motion. The results of dockside test showed that the heave motion of the barge's motion can be reduced by more than 45%.

A new base plate system using deformed reinforcing bars for concrete filled tubular column

  • Park, Yong-Myung;Hwang, Won-Sup;Yoon, Tae-Yang;Hwang, Min-Oh
    • Steel and Composite Structures
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    • v.5 no.5
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    • pp.375-394
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    • 2005
  • An experimental study was conducted to develop a new base plate anchorage system for concrete filled tubular column under an axial load and a moment. The column was connected to a concrete foundation using ordinary deformed reinforcing bars that are installed at the inside and outside of the column. In order to investigate the moment resisting capacity of the system, horizontal cyclic loads are applied until the ultimate condition is reached with the axial load held constant. To derive a design method for moment resisting capacity, the reinforced concrete section approach was investigated with the assumption of strain compatibility. The results by this approach agreeded well with those of experiments when the bearing pressure of confined concrete and tangent modulus of steel bars are assumed appropriately. Also, it was found that the column interaction curve can be used to predict the yield strength of the base plate system.

Coupled CFD-FEM simulation of hydrodynamic responses of a CALM buoy

  • Gu, Haoyuan;Chen, Hamn-Ching;Zhao, Linyue
    • Ocean Systems Engineering
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    • v.9 no.1
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    • pp.21-42
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    • 2019
  • In this paper, the Finite-Analytic Navier-Stokes (FANS) code is coupled with an in-house finite-element code to study the dynamic interaction between a floating buoy and its mooring system. Hydrodynamic loads on the buoy are predicted with the FANS module, in which Large Eddy Simulation (LES) is used as the turbulence model. The mooring lines are modeled based on a slender body theory. Their dynamic responses are simulated with a nonlinear finite element module, MOORING3D. The two modules are coupled by transferring the forces and displacements of the buoy and its mooring system at their connections through an interface module. A free-decay model test was used to calibrate the coupled method. In addition, to investigate the capability of the present coupled method, numerical simulations of two degree-of-freedom vortex-induced motion of a CALM buoy in uniform currents were performed. With the study it can be verified that accurate predictions of the motion responses and tension responses of the CALM buoy system can be made with the coupling CFD-FEM method.

Development of a Novel Cell Surface Attachment System to Display Multi-Protein Complex Using the Cohesin-Dockerin Binding Pair

  • Ko, Hyeok-Jin;Song, Heesang;Choi, In-Geol
    • Journal of Microbiology and Biotechnology
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    • v.31 no.8
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    • pp.1183-1189
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    • 2021
  • Autodisplay of a multimeric protein complex on a cell surface is limited by intrinsic factors such as the types and orientations of anchor modules. Moreover, improper folding of proteins to be displayed often hinders functional cell surface display. While overcoming these drawbacks, we ultimately extended the applicability of the autodisplay platform to the display of a protein complex. We designed and constructed a cell surface attachment (CSA) system that uses a non-covalent protein-protein interaction. We employed the high-affinity interaction mediated by an orthogonal cohesin-dockerin (Coh-Doc) pair from Archaeoglobus fulgidus to build the CSA system. Then, we validated the orthogonal Coh-Doc binding by attaching a monomeric red fluorescent protein to the cell surface. In addition, we evaluated the functional anchoring of proteins fused with the Doc module to the autodisplayed Coh module on the surface of Escherichia coli. The designed CSA system was applied to create a functional attachment of dimeric α-neoagarobiose hydrolase to the surface of E. coli cells.

A Study on the Behaviour of Mooring System for Guyed Tower (Guyed Tower의 계류시스템에 관한 연구)

  • Park, Young Suk;Lee, Myong Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.1
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    • pp.11-23
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    • 1989
  • This paper presents the results of the numerical analysis on the behaviour of mooring system of offshore guyed tower. Finite element method is used and geometric nonlinearities are considered in the analysis of mooring line. The governing equilibrium equations are derived by the principle of virtual work, and modified Newton-Raphson method and Newmark-${\beta}$ method are employed in response calculations. The drag and inertia effects of fluid are included using a Morrison type equation. The influences of changing typical parameters like initial inclination and tension of line at the guy attachment point, the length of clump weight, its unit weight and the anchor line length are examined. The effects of idealising the clump weight as a point load(lumped clump weight) on the behaviour of mooring lines are also discussed. Numerical examples demonstrate the validity and capability of the mathematical formulation.

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Stability Evaluation of Earth Retaining Structure using Tower Truss System (새로운 무지보 흙막이 공법의 안정성 평가)

  • Kim, Young-Seok;Kim, Ju-Hyong;Kim, Young-Nam;Kim, Seong-Hwan;Lee, Sung-Reol
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1324-1329
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    • 2009
  • Needs for underground space development and utilization have been increasing in urban area. The conventional strutting method in excavation is effective to restrain the ground movements and displacements of earth structures but inefficient for workers because of small working space. The conventional earth reinforcement methods such as earth-anchor and soil-nailing also have limitation to apply in urban area due to threats to stability of adjacent buildings around excavation boundaries. Recently, many types of earth retaining structures are being developed to overcome disadvantages of conventional excavation methods in urban area. In this study, a series of numerical analyses were performed with MIDAS GTS, geotechnical analysis program and MIDAS Civil, structural analysis design program to evaluate behavior and stability of the new type of non-supporting earth retaining structure, called Temporary Tower System (TTS), consisting of tower truss structures with much economical and spatial advantage.

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INJURY PERFORMANCE EVALUATION OF THE CHILD RESTRAINT SYSTEMS

  • Shin, Y.J.;Kim, H.;Kim, S.B.;Kim, H.Y.
    • International Journal of Automotive Technology
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    • v.8 no.2
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    • pp.185-191
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    • 2007
  • The new FMVSS 208, 213, 225 regulations include automatic suppression of airbags to prevent low-risk airbag deployment and the use of child seats with a rigid-bar anchor system. The regulations mean that children must sit in the rear seat, but do not include other specific safety measures for their protection. In the rear, restraint equipment consists of three-point shoulder/lap belts for the outside seats and a static two-point lap belt in the middle, with no additional devices such as pretensioners or load limiters; this is far from optimal for children. This study investigated injury rates using a 3-year-old-child dummy. ECE R44 sled tests used a booster, a speed of 48 km/h, and a 26- to 32-g rectangular deceleration pulse. While seated on a booster, the dummies were restrained by an adult shoulder/lap three-point belt. HIC_15 msec, Chest G and Nij were somewhat lower with an emergency locking retractor (ELR)+pretensioner+load limiter than with only an ELR or with ELR+pretensioner. However, the current seat-belt system results in injury rates that exceed the limit for OOP performance under the new FMVSS 208 regulations.