• Title/Summary/Keyword: Scale-free

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Study on Status of Barrier Free Certification & Improvement Strategies (여객자동차 터미널 이동편의시설 BF 실태 및 개선방안 연구)

  • Park, Shin-Won;Cho, Young-Tae
    • Land and Housing Review
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    • v.7 no.4
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    • pp.225-237
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    • 2016
  • This study is to investigate actual condition of passenger terminals, public facilities which are used by unspecified individuals, with high spread effect of certification system of Barrier Free introduced in 2007, evaluate possibility of the certification and prepare an effective way for certification in order to spread and settle the certification system. According to the investigation on the facilities' equipment level of 349 passenger terminals, which being nationally operated, 217 terminals could be certified and non-certified were 58. And, 29 was evaluated as the passenger terminals with high possibility to get Barrier Free certification by small scale of remodeling. The level of Barrier Free of investigated passenger terminals, according to the actual condition with certification index, were 40~55 percent. While the level of Barrier Free of internal facilities of the terminals was over 90percent, the level of sanitary facilities, information facilities, etc. fell short of 50 percents. In this study, pilot project of Barrier Free certification is proposed for enhance of passenger terminal facilities. Moreover, the selection of passenger terminals with high possibility of certification, local governments' strong will as the targets of pilot project for improvement of amenity level and Barrier Free certification and monitoring the project results are the way of the project.

A Study on Change the Container Terminal Yard Occupations by Handling System (장비제원에 따른 컨테이너 터미널 장치장 점유율 변화에 관한 연구)

  • Song Yong-Seok;Park Jeong-Jae;Nam Ki-Chan;Kwak Kyu-Seok;An Ki-Myung
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.303-307
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    • 2004
  • The scale of ship's cargo transport is getting larger, more economics of scale are gained the speed is higher and the size of quay fundling equipment in container terminal is larger. The productivity cf the quay qffects occupation for limited scale of yard. This paper aims to calculate the yard occupation by handling systems, such as OHBC, RMGC, RTTC, etc, and lay-out.

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A nonlocal strain gradient theory for nonlinear free and forced vibration of embedded thick FG double layered nanoplates

  • Mahmoudpour, E.;Hosseini-Hashemi, SH.;Faghidian, S.A.
    • Structural Engineering and Mechanics
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    • v.68 no.1
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    • pp.103-119
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    • 2018
  • In the present research, an attempt is made to obtain a semi analytical solution for both nonlinear natural frequency and forced vibration of embedded functionally graded double layered nanoplates with all edges simply supported based on nonlocal strain gradient elasticity theory. The interaction of van der Waals forces between adjacent layers is included. For modeling surrounding elastic medium, the nonlinear Winkler-Pasternak foundation model is employed. The governing partial differential equations have been derived based on the Mindlin plate theory utilizing the von Karman strain-displacement relations. Subsequently, using the Galerkin method, the governing equations sets are reduced to nonlinear ordinary differential equations. The semi analytical solution of the nonlinear natural frequencies using the homotopy analysis method and the exact solution of the nonlinear forced vibration through the Harmonic Balance method are then established. The results show that the length scale parameters give nonlinearity of the hardening type in frequency response curve and the increase in material length scale parameter causes to increase in maximum response amplitude, whereas the increase in nonlocal parameter causes to decrease in maximum response amplitude. Increasing the material length scale parameter increases the width of unstable region in the frequency response curve.

A Study on the Hot Cracking Phenomena of Cu-Ni Bearing Hot Rolled Steels (Cu-Ni 첨가형 열연강판의 열간균열현상에 관한 연구)

  • Yun, In-Taek;Jo, Yeol-Rae;Kim, Sun-Ho;Kim, In-Bae
    • Korean Journal of Materials Research
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    • v.9 no.4
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    • pp.335-340
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    • 1999
  • The hot cracking phenomena and phase behaviors during hot working process of Cu-Ni bearing hot rolled steels were investigated by a $90^{\circ}$bending tests, BSE image analysis and EDS analysis. For aNi-free 1.2% Cu bearing steel, the surface hot cracking occurred about $1100^{\circ}C$ due to a liquid state Cu-enriched phase formed continuously at the interface between oxide scale and matrix. The liquid Cu-enriched phase penetrated into austenite grain boundaries and caused surface cracking during the hot working. In case of 0.6% Ni containing 1.2% Cu-Ni bearing steel, solid state Cu-Ni-riched phase existed at the scale/matrix interface as a discontinuous type. But the higher addition of 1.2% Ni, solid state Ni-Cu-riched phase was formed dominantly in the oxide scale. It was found that the addition of Ni suppressed the surface cracking of 1.2% Cu bearing steel by eliminating the liquid state Cu-enriched phase.

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New record of commensal scale worms, Arctonoe vittata (Grube, 1855) and Hyperhalosydna striata (Kinberg, 1856) (Polychaeta: Polynoidae) from Korean waters

  • Park, Taeseo;Lee, Sang-kyu;Kim, Won
    • Journal of Species Research
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    • v.5 no.3
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    • pp.517-529
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    • 2016
  • Two scale worms of the family Polynoidae, Arctonoe vittata (Grube, 1855) and Hyperhalosydna striata (Kingberg, 1856) were found for the first time from Korea by SCUBA diving survey. The two species are free-living organisms or associated commensally with a wide variety of other invertebrates. Specimens of A. vittata were collected from the East Sea and were closely associated with asteroids, holothuroids, gastropods and nudibranchs species. Specimens of H. striata were collected from Jeju-do Island, and of these, one specimen was collected in a tube of eunicid species. The two species can be easily distinguished from their congeners by distinct morphological characteristics as follows: (1) A. vittata has pigmented band near segment eight and two kinds of neurochaetae; (2) H. striata has reddish-brown longitudinal striped elytra. The morphological key characteristics of both species agreed well with their original descriptions and redescriptions. In this study, the descriptions, detailed illustrations and ecological photographs of two species based on Korean materials were provided.

Review of Operational Multi-Scale Environment Model with Grid Adaptivity

  • Kang, Sung-Dae
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.10 no.S_1
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    • pp.23-28
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    • 2001
  • A new numerical weather prediction and dispersion model, the Operational Multi-scale Environment model with Grid Adaptivity(OMEGA) including an embedded Atmospheric Dispersion Model(ADM), is introduced as a next generation atmospheric simulation system for real-time hazard predictions, such as severe weather or the transport of hazardous release. OMEGA is based on an unstructured grid that can facilitate a continuously varying horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from 20 -30 meters in the boundary layer to 1 km in the free atmosphere. OMEGA is also naturally scale spanning and time. In particular, the unstructured grid cells in the horizontal dimension can increase the local resolution to better capture the topography or important physical features of the atmospheric circulation and cloud dynamics. This means the OMEGA can readily adapt its grid to a stationary surface, terrain features, or dynamic features in an evolving weather pattern. While adaptive numerical techniques have yet to be extensively applied in atmospheric models, the OMEGA model is the first to exploit the adaptive nature of an unstructured gridding technique for atmospheric simulation and real-time hazard prediction. The purpose of this paper is to provide a detailed description of the OMEGA model, the OMEGA system, and a detailed comparison of OMEGA forecast results with observed data.

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Connection between a Small-Scale Emerging Island and Double Arc Loops Producing a M6.5 Flare in Active Region 12371

  • Kang, Jihye;Inoue, Satoshi;Moon, Yong-Jae;Magara, Tetsuya;Kusano, Kanya
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.81.3-81.3
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    • 2017
  • In this paper, we report a small-scale emerging island and double arc loops, which are associated with a M6.5 flare, in Active Region 12371. We investigate the spatial and temporal changes of both photospheric magnetic fields using SDO/HMI data and coronal magnetic structures obtained from nonliner force-free field (NLFFF) extrapolation. From the vector magnetograms, we find a small-scale emerging island near the main polarityy inversion line about three hours before the flare. The island has a strong shear angle, which is determined by difference between transverse component of observed field and potential field, of around 90 degrees. Furthermore, the NLFFF well reproduces a sigmoidal structure seen in SDO/AIA 94, which is consistent with the double arc loops configuration suggested by Ishiguro and Kusano (2017) who introduced a magnetic configuration showing the double arc instability. The observed emerging island is located among the double arc loops, which is also supproted by their model. Finally, there was an eruption (M6.5 flare) associated with the loops. We discuss a possible role of the double arc instability for the eruption.

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A Direct Numerical Simulation Study on the very Large-Scale Motion in Turbulent Boundary Layer (직접수치모사를 이용한 난류경계층 내의 거대난류구조 연구)

  • Lee, Jae-Hwa;Sung, Hyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.12
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    • pp.977-982
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    • 2009
  • Direct numerical simulation (DNS) of a turbulent boundary layer with moderate Reynolds number was performed to scrutinize streamwise-coherence of hairpin packet motions. The Reynolds number based on the momentum thickness (${\theta}_{in}$) and free-stream velocity (U${\infty}$) was varied in the range $Re_{\theta}$=1410${\sim}$2540 which was higher than the previous numerical simulations in the turbulent boundary layer. In order to include the groups of hairpin packets existing in the outer layer, large computational domain was used (more than 50${\delta}_o$, where ${\theta}_o$ is the boundary layer thickness at the inlet in the streamwise domain). Characteristics of packet motions were investigated by using instantaneous flow fields, two-point correlation and conditional average flow fields in xy-plane. The present results showed that a train of hairpin packet motions was propagating coherently along the downstream and these structures induced the very large-scale motions in the turbulent boundary layer.

Effective electromechanical coupling coefficient of adaptive structures with integrated multi-functional piezoelectric structural fiber composites

  • Koutsawa, Yao;Tiem, Sonnou;Giunta, Gaetano;Belouettar, Salim
    • Smart Structures and Systems
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    • v.13 no.4
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    • pp.501-515
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    • 2014
  • This paper presents a linear computational homogenization framework to evaluate the effective (or generalized) electromechanical coupling coefficient (EMCC) of adaptive structures with piezoelectric structural fiber (PSF) composite elements. The PSF consists of a silicon carbide (SiC) or carbon core fiber as reinforcement to a fragile piezo-ceramic shell. For the micro-scale analysis, a micromechanics model based on the variational asymptotic method for unit cell homogenization (VAMUCH) is used to evaluate the overall electromechanical properties of the PSF composites. At the macro-scale, a finite element (FE) analysis with the commercial FE code ABAQUS is performed to evaluate the effective EMCC for structures with the PSF composite patches. The EMCC is postprocessed from free-vibrations analysis under short-circuit (SC) and open-circuit (OC) electrodes of the patches. This linear two-scale computational framework may be useful for the optimal design of active structure multi-functional composites which can be used for multi-functional applications such as structural health monitoring, power harvest, vibration sensing and control, damping, and shape control through anisotropic actuation.

On the size-dependent behavior of functionally graded micro-beams with porosities

  • Amar, Lemya Hanifi Hachemi;Kaci, Abdelhakim;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • v.64 no.5
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    • pp.527-541
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    • 2017
  • In this work, a new hyperbolic shear deformation beam theory is proposed based on a modified couple stress theory (MCST) to investigate the bending and free vibration responses of functionally graded (FG) micro beam made of porous material. This non-classical micro-beam model introduces the material length scale coefficient which can capture the size influence. The non-classical beam model reduces to the classical beam model when the material length scale coefficient is set to zero. The mechanical material properties of the FG micro-beam are assumed to vary in the thickness direction and are estimated through the classical rule of mixture which is modified to approximate the porous material properties with even and uneven distributions of porosities phases. Effects of several important parameters such as power-law exponents, porosity distributions, porosity volume fractions, the material length scale parameter and slenderness ratios on bending and dynamic responses of FG micro-beams are investigated and discussed in detail. It is concluded that these effects play significant role in the mechanical behavior of porous FG micro-beams.