• Title/Summary/Keyword: Macroscopic Characteristics

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A Study on the Policy on Digital Contents Archiving in the Field of Science and Technology (과학기술분야 디지털 콘텐츠의 아카이빙 정책 연구)

  • Kwak, Seung-Jin;Choi, Jae-Hwang;Bae, Kyung-Jae;Jung, Young-Mi
    • Journal of Information Management
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    • v.42 no.4
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    • pp.115-136
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    • 2011
  • Recently, the cases of archiving for digital contents are being increased throughout the world. Owing to the characteristics of digital contents including the issues on volatile property and authenticity, preservation weakness, and aging in the reproductive tool, it requires special management for long-term preservation. A successful digital archiving seems to be possible in the stage-oriented practice through the cooperation of interested organizations based on the systematically established and stipulated policy. This is the basic study that was designed for the establishment of the policy on digital contents archiving in KISTI(Korea Institute of Science and Technology Information), which is a representative organization for the distribution of science and technology information. By investigating and analyzing the cases of overseas policies on digital contents archiving, it intended to understand the framework of digital archiving policy while suggesting measures on the macroscopic items that were included in the archiving policies through the interview conducted to expert groups.

Improvement of Biotope-Area-Ratio-Indicator and Appraisal System Applicable to Environmental Impact Assessment Projects (환경영향평가 대상사업에 적용가능한 생태면적률 지표 평가체계 개선)

  • Lee, Gwan-Gyu;Lee, Sang-Hyuk;Kim, Gyung-Ho;Lee, Jung-Hwan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.5
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    • pp.113-125
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    • 2011
  • Since the government of Korea (Ministry of Environment, MOE) introduced the policy applying 'Biotope-Area-Ratio-Indicator (BARI)' to huge residential land developments which Environmental Impact Assessment (EIA) should be performed, MOE has come to have the necessity to apply the indicator concretely at the stage of Prior Environment Review System (PERS) and EIA in various types of large scale land development projects. This study was conducted with the aim of supporting the application of BARI and related decision making in various other types of EIA projects as well as residential development projects through remodeling the system to apply the indicator of the past. Through the analysis of the problems in applying the past BARI and experimental appraisals to 11 types of EIA projects, the results and implications as follows were drawn. First, it's possible to extend the range of applications of BARI, which has been applied to only residential land development project, to all kinds of projects with area-typed land use pattern out of environmental impact assessment target projects. Second, it's also possible to set a target value into which regional characteristics and differences among locational properties are reflected. In addition, it's come to be able to differentially apply the target value of BARI according to the condition of the existing site. Third, it's improved to be able to suggest a macroscopic target value at the stage of PERS and to set detailed target values in each detailed land use at the stage of EIA. The key point underlies inducing methodology to determine target values to secure more permeable land coverage ratio for detailed land use patterns at the stage of EIA by making it possible to calculate BARI of the present land cover condition of the EIA target projects.

The Finite Element Analysis for Calculations of Equivalent Elastic Constants Using the Homogenization Method (균질화기법과 유한요소법을 이용한 복합재료의 등가탄성계수 산정)

  • Yun, Seong-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.1
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    • pp.51-61
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    • 2000
  • This paper discusses the homogenization method to determine effective average elastic constants of a linear structure by considering its microstructure. A detailed description on the homogenization method is given for the linear elastic material and then the finite element approximation is performed for an investigation of elastic properties. An asymptotic expansion is carried out in the cross-section area, or in the unit cell. Two and three lay-up structures made up of individual isotropic constituents are chosen for numerical examples to check discrepancies between results generated by this theoretical development and the conventional approach. Asymptotic characteristics of the process in extracting the stiffness of structure locally formed by spatial repetitions yield underestimated values of stiffness. These discrepancies are detected by the asymptotic corrective term which is ascribed to considerations of microscopic perturbations and proved in the finite element formulation. The asymptotic analysis is the more reasonable in analysing the composite material, rather than the conventional approach to calculate the macroscopic average for elastic properties.

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A Study on Flexural Behavior of Externally Reinforced R.C. Beam with Carbon Fiber Sheet : In Case of Constructional Deficiencies (탄소섬유시트로 보강된 철근콘크리트 보의 시공불량시 휨 거동에 관한 연구)

  • Park, Hyun-Jung;Lee, Hong-Ju;Park, Sung-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.1
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    • pp.95-102
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    • 2002
  • The flexural behavior of the reinforced concrete (RC) structure upgraded by external reinforcements was examined in this study. It is well known that the incorporation of carbon fiber sheet (CFS) with concrete is one of the most effective ways to strengthen the RC structure. Complete bonding is required between CFS and concrete in order to make the RC structure provide its full function until the time the Re structures serve. Many studies have reported that construction deficiencies have caused the debonding of the CFS from concrete before the RC structure with CFS reaches its ultimate capacity. This research took a systematic look at the failure mechanism, macroscopic load-deformation characteristics, the maximum load applied, and maximum bending moment when construction deficiencies exist. The results of the experiment conducted were compared with theoretically derived values. In the future, the results of this investigation will help minimize the factors of construction deficiencies, which may occur when CFS is used to reinforce a RC structure. The experiment was manipulated with steel reinforcement ratio and piles of CFS on a total of 14 beams ($20cm{\times}30cm{\times}240cm$). The results showed that internal moment capacity increased even when construction deficiencies existed. However, RC structures with CFS in the field still contain a considerable level of potential risks.

Effect of Transesterification on the Characteristics of PET/PEN Blend Flexible Substrate (상호에스테르 교환반응이 폴리(에틸렌 테레프탈레이트)/폴리(에틸렌 나프탈레이트) 블렌드 유연기관 특성에 미치는 영향)

  • Kim, Jae-Hyun;Kim, Whan-Ki;Yum, Ju-Sun;Kang, Ho-Jong
    • Polymer(Korea)
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    • v.35 no.3
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    • pp.249-253
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    • 2011
  • The effect of morphological development in PET/PEN blending on the physical properties of PET/PEN blend film as a flexible substrate was investigated. The two phase morphology was obtained in PET/PEN blends and it caused the improvement of dimensional stability of PET/PEN blend as a flexible substrate. The two phase morphology and crystallinity of PET/PEN blends could be controlled by the transesterification between PET and PEN during the film processing and this macroscopic structural development affected the dimensional stability of PET/PEN blend films. Better dimensional stability was obtained with increasing crystallinity and decreasing the level of transesterification.

A Study on NYCHA Infill Development in NYC -Focusing on the Housing Affordability & Social Soundness- (뉴욕시 NYCHA 인필개발에 대한 분석적 고찰 -주거저렴성 및 사회적 건전성 확보를 중심으로-)

  • Lee, Woo-Hyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.228-235
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    • 2016
  • The purpose of this study is to analyze 3 pilot developments, collectively known as the NYCHA Infill Development, in the Bronx, Brooklyn and NYC, as a case study focusing on the characteristics of the business structure to enhance the public good by ensuring the provision of more affordable housing within the developments. As part of the "Next Generation NYCHA" macroscopic housing policy in NYC, this case is considered to respond to the crisis of affordable housing that reflects the domestic situation. The results of this study may have implications for domestic housing problems. Moreover, it may help to provide diverse methodologies applicable to public housing development.

S. Korea's Approach Strategy through Policy Analysis of Major Countries to Promote the Use of Forest Biomass as Renewable Energy (재생에너지로서 산림바이오매스 활용 촉진을 위한 주요국의 정책분석을 통한 한국의 접근전략)

  • Lee, Seung-Rok;Park, Sehun;Koh, Moon-Hyun;Han, Gyu-Seong
    • New & Renewable Energy
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    • v.18 no.3
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    • pp.10-22
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    • 2022
  • Forest biomass energy is based on scientific evidence in response to carbon neutrality and the climate crisis, international consensus, and environmental-geographic characteristics of each nation. In this study, the authors aimed to analyze macroscopic forest biomass energy policies for ten major countries. They categorized them into six detailed categories (Sustainable utilization, Cascading Uutilization, Replacement of fossil fuel/Carbon intensive products, Utilization of forest by-products/residues as the source of energy, Contribution to carbon-neutral/climate change, and Biomass combined with CCS/CCUS ). In addition, the surveyed nations have developed a policy consensus on the active use of forest biomass with sustainable forest management except for the cascading utilization category. Furthermore, the authors evaluated the mid to long-term plans of the Korean government for improvements in the policy and legal aspects. As a result, the authors derived four major directions that South Korea should approach strategically in the future (1) secure financial resources for sustainable forest management and stimulating investment in the timber industry, (2) promote unified policies to establish a bio-economy, (3) enhancement of the forest biomass energy system, and (4) reorganization and promotion of strategy centered on the opinions of field experts in internal and external instability.

Simulation of the fracture of heterogeneous rock masses based on the enriched numerical manifold method

  • Yuan Wang;Xinyu Liu;Lingfeng Zhou;Qi Dong
    • Geomechanics and Engineering
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    • v.34 no.6
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    • pp.683-696
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    • 2023
  • The destruction and fracture of rock masses are crucial components in engineering and there is an increasing demand for the study of the influence of rock mass heterogeneity on the safety of engineering projects. The numerical manifold method (NMM) has a unified solution format for continuous and discontinuous problems. In most NMM studies, material homogeneity has been assumed and despite this simplification, fracture mechanics remain complex and simulations are inefficient because of the complicated topology updating operations that are needed after crack propagation. These operations become computationally expensive especially in the cases of heterogeneous materials. In this study, a heterogeneous model algorithm based on stochastic theory was developed and introduced into the NMM. A new fracture algorithm was developed to simulate the rupture zone. The algorithm was validated for the examples of the four-point shear beam and semi-circular bend. Results show that the algorithm can efficiently simulate the rupture zone of heterogeneous rock masses. Heterogeneity has a powerful effect on the macroscopic failure characteristics and uniaxial compressive strength of rock masses. The peak strength of homogeneous material (with heterogeneity or standard deviation of 0) is 2.4 times that of heterogeneous material (with heterogeneity of 11.0). Moreover, the local distribution of parameter values can affect the configuration of rupture zones in rock masses. The local distribution also influences the peak value on the stress-strain curve and the residual strength. The post-peak stress-strain curve envelope from 60 random calculations can be used as an estimate of the strength of engineering rock masses.

A Study on Makerspace: Focusing on Its Urbanism and Placeness (산업공간으로서 메이커스페이스의 도시성(urbanism)과 장소성(placeness))

  • Jeong Seok Ha
    • Journal of the Economic Geographical Society of Korea
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    • v.25 no.4
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    • pp.547-567
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    • 2022
  • In this study, I focus on makerspaces, which have rapidly spread since the late 2000s in the world's major cities. Makerspaces, born amid great social change, reflect the core characteristics of industrial space. I analyze the makerspace based on the theoretical perspectives of urbanism in the macroscopic aspect and placeness in the microscopic aspect. The urbanism of makerspaces is manifested through entry into the inner cities and their connections with urban capabilities. This means that convergence with innovation factors is becoming more important than optimization of factor costs and agglomeration economies in the locational determinants of industrial space. The placeness of makerspaces is being re-formed through an emphasis on taste, the expansion of autonomy, and the strengthening of connections. This reveals how the value creation process within the industrial space is changing, from forming-placelessness through standardization, uniformity, and compartmentalization to forming-placeness through restoration of individual humanity and interaction. The results of the urbanism and placenesss analysis carry implications for the present moment, when it is necessary to diversify the spatial planning of industrial spaces.

Crack initiation mechanism and meso-crack evolution of pre-fabricated cracked sandstone specimens under uniaxial loading

  • Bing Sun;Haowei Yang;Sheng Zeng;Yu Yin;Junwei Fan
    • Geomechanics and Engineering
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    • v.33 no.6
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    • pp.597-609
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    • 2023
  • The instability and failure of engineered rock masses are influenced by crack initiation and propagation. Uniaxial compression and acoustic emission (AE) experiments were conducted on cracked sandstone. The effect of the crack's dip on the crack initiation was investigated using fracture mechanics. The crack propagation was investigated based on stress-strain curves, AE multi-parameter characteristics, and failure modes. The results show that the crack initiation occurs at the tip of the pre-fabricated crack, and the crack initiation angle increases from 0° to 70° as the dip angle increases from 0° to 90°. The fracture strength kcr is derived varies in a U-shaped pattern as β increased, and the superior crack angle βm is between 36.2 and 36.6 and is influenced by the properties of the rock and the crack surface. Low-strength, large-scale tensile cracks form during the crack initiation in the cracked sandstone, corresponding to the start of the AE energy, the first decrease in the b-value, and a low r-value. When macroscopic surface cracks form in the cracked sandstone, high-strength, large-scale shear cracks form, resulting in a rapid increase in the AE energy, a second decrease in the b-value and an abrupt increase in the r-value. This research has significant theoretical implications for rock failure mechanisms and establishment of damage indicators in underground engineering.