• 제목/요약/키워드: lower infrastructure

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유망식생사면 하부철망 유실에 대한 연구 (Vegetation Slopes for the loss of the lower gridlock Research)

  • 전국재;신창건;박재영;장범수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.1334-1341
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    • 2010
  • 유망식생공을 실시한 사면에 집중강우가 유입되면 단위중량이 증가하여 중력방향으로 이동을 하게 되며, 그에 따라 망이 유실되는 경우가 많아, 이를 고려한 점착력 확보가 요구되고 있는 실정이다. 강우와 사고사례에 따른 분석을 통하여 적절한 점착력을 확보하기 위한 기준마련 및 제시를 통해 국도이용의 안정성을 확보하고자 한다.

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Impact Analysis of Intellectual Property Infrastructure

  • Sohn, Soo Jeoung
    • STI Policy Review
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    • 제4권2호
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    • pp.1-18
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    • 2013
  • As the value and role of intellectual property increases in our knowledge-based economy, countries around the world have exerted various efforts to secure, utilize, and protect their intellectual property. The present study diagnoses the level of IP infrastructure of major OECD countries and analyzes their characteristics and impact. According to the diagnosis, the US, Switzerland, and Germany form a leading group followed by the mid-level countries of Korea, Ireland, Australia, and France, with Spain and Italy in the bottom group. In contrast to Korea's competitiveness in S&T and R&D infrastructures, its competitiveness in IP infrastructure is lower than the OECD average. This is thought to be due to Korea's IP infrastructure being hastily formed under the influence of international pressures rather than having been gradually built up by internal needs. A TFP analysis of the impact of IP infrastructure on economic growth shows IP infrastructure positively influences economic growth. Though this analysis is limited due to inability to secure sufficient data and indicators, it is a useful guide for understanding the nature and key characteristics of IP infrastructure.

A simplified design approach for modelling shear force demand on tower walls supported on a transfer structure in regions of lower seismicity

  • Yacoubian, Mehair;Lam, Nelson;Lumantarna, Elisa;Wilson, John L.
    • Earthquakes and Structures
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    • 제15권1호
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    • pp.97-111
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    • 2018
  • Buildings featuring a transfer structure can be commonly found in metropolitan cities situated in regions of lower seismicity. A transfer structure can be in the form of a rigid plate or an array of deep girders positioned at the podium level of the building to support the tower structure of the building. The anomalous increase in the shear force demand on the tower walls above the podium is a major cause for concern. Design guidance on how to quantify these adverse effects is not available. In this paper a simplified method for quantifying the increase in the shear force demand on the tower walls is presented. In view of the very limited ductile nature of this type of construction the analysis presented herein is based on linear elastic behaviour.

사회적 자본 및 정보기술 하부구조의 도입수준과 지식경영 과정들에 대한 영향 (The Adoption Degrees of Social Capital and IT Infrastructure, and Their Effects on Knowledge Management Processes)

  • 최종민
    • 한국정보시스템학회지:정보시스템연구
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    • 제18권3호
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    • pp.183-210
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    • 2009
  • This study investigated the degrees of knowledge management processes according to the levels of social capital(i.e., inter-departmental communication, trust, cooperation and integration) as well as information technology(IT) infrastructure(i.e., knowledge storage and transfer IT, and knowledge search IT) in Korean manufacturing firms. We also demonstrated the differences in organizational performance under various degrees of knowledge management processes. Through cluster analysis with social capital variables, we classified sample firms into five groups; 'the highest firms', 'higher firms', 'middle firms', 'lower firms', and 'the lowest firms'. It was also observed that the degrees of knowledge management processes and organizational performance in 'the highest firms' is the highest. With a structural equation modeling technique, the causal relationships among social capital, IT infrastructure, knowledge management processes, and organizational performance were confirmed. Hence, it is concluded that social capital and IT infrastructure have direct effects on knowledge management processes, and indirectly influence organizational performance through the degrees of knowledge management processes.

하계해석을 이용한 수직방향 지진계수 영향에 따른 비탈면의 안정성 평가 연구 (A Study on the Estimation of Slope Stability under the Influence of the Vertical Direction Seismic Coefficient Using Lower Bound Analysis)

  • 최상호;김종민;김용수
    • 한국지반공학회논문집
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    • 제28권12호
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    • pp.123-131
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    • 2012
  • 최근에 발생한 아이티지진, 칠레지진의 지진파 기록에서 일반적으로 비탈면 안정해석에서 무시되었던 수직방향 지진가속도 성분이 크게 나타났다. 특히, 수직방향 지진성분은 진원이 내륙에 위치한 경우 더욱 뚜렷하게 나타난다. 그러므로 설계에 수직방향 지진성분을 고려하지 않은 지반 구조물들은 많은 인명과 재산 피해를 가져올 수 있다. 따라서, 본 연구는 지진계수비에 따른 수평방향 항복지진계수의 하계해를 산정하였고, 비탈면 안정성에 미치는 영향을 평가하였다. 또한, 한계상태 수직방향 지진계수의 방향(상향, 하향)을 결정할 수 있는 관계식을 제안하였다.

The Impact of Electricity Infrastructure Quality on Firm Productivity: Empirical Evidence from Southeast Asian Countries

  • BUI, Lan Thi Hoang;NGUYEN, Phi-Hung
    • The Journal of Asian Finance, Economics and Business
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    • 제8권9호
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    • pp.261-272
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    • 2021
  • Rapid economic growth in recent years has caused a surge in energy consumption among Southeast Asian countries and laid a considerable burden on the already inadequate power infrastructure. As a result, frequent blackouts and prolonged outages have become common and weakened firm productive performance in those years. The main objective of this study is to examine the impact of power infrastructure quality on the performance of Southeast Asian manufacturing firms. In this study, the World Bank Enterprise Surveys was employed as the training dataset of 4723 manufacturing firms in the period of 2015-2016. The results of this study reveal that industrial firms that suffered from power outages had consistently lower productivity. As measured by the length of such events, more severe outages tend to be more harmful to the firm. Furthermore, the findings also indicated that most firms relied on self-generated electricity to reduce the negative impact of power outages, but this does not bring many benefits when operating at a small scale in some countries. Consequently, this study contributes to a growing literature that examines the economic impact of public infrastructure and how detrimental the poor state of such services is to a firm's downstream operations, productivity, and growth.

REBUILDING RAIL INFRASTRUCTURE IN NIGERIA: POLICY, PROBLEMS AND PROSPECTS

  • Oyefuga, Ben;Egbetokun, Abiodun
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1883-1895
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    • 2007
  • With a land area of 910,768 sq. km, population estimate of 150 million people and GDP-growth rate of 6.9% per annum (2006 est), the centrality of effective public transportation in Nigeria is readily seen. In this regard, rail transportation offers much potential because of its relative safety, reliability, lower cost to the users and being singularly capable of transforming the national economy through mass movement of people, goods and services. Within this context, the demand for an effective railway system, and the enormous potentials for profitable investment in rail infrastructure in Nigeria, is indisputable. Beginning with the history, the paper discusses the main problems of Nigeria's railway transport system; and then makes policy suggestions, after considering the potentials of rebuilding the rail infrastructure. The necessity of this work is premised on the fact that there is a significant gap in critical knowledge about Nigeria's railway transport system.

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Real-scale field testing for the applicability examination of an improved modular underground arch culvert with vertical walls

  • Tae-Yun Kwon;Jin-Hee Ahn;Hong-duk Moon;Kwang-Il Cho;Jungwon Huh
    • Advances in concrete construction
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    • 제15권6호
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    • pp.377-389
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    • 2023
  • In this study, an improved modular arch system with the lower arch space composed of a precast arch block and an outrigger was proposed as an underground culvert, and its applicability and structural behaviors were confirmed. This modular arch culvert structure with vertical walls was designed using precast blocks and by adjusting the placement spacing of concrete blocks to the upper part form an arch shape and the lower part form a vertical wall shape, based on previously researched modular arch systems. Owing to the vertical wall of the proposed modular arch system, it is possible to secure a load-carrying capacity and an arch space that can sufficiently resist the earth pressure generated from the backfill soil and loading on the arch system. To verify the structural characteristics, and applicability of the proposed modular precast arch culvert structure, a full-scale modular culvert specimen was fabricated, and a loading test was conducted. By examining its construction process and loading test results, the applicability and constructability of the proposed structure were analyzed along with its structural characteristics. In addition, its the structural predictability and safety for the applicability were evaluated by comparing the construction process and loading test results with the FE analysis results.

농업기반정비사업 편익산정을 위한 지표 개선방안 (A Study of the Economic Evaluation for the Agricultural Infrastructure Projects)

  • 김영주;최병한;조래청;최영완;김윤식
    • 농촌계획
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    • 제20권2호
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    • pp.139-150
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    • 2014
  • The purposes of this research are to review the current economic measures to be used to assess the economic effects of agricultural infrastructure projects, to find some effects not included into the current measures, and to suggest new additional economic measures. So thus, economic assessment for agricultural infrastructure projects has been criticized to be overestimated. For example, some research reported that the projects enhanced rice productivity by 20% or 30%. We suggest four new measures to evaluate economic effects of agricultural infrastructure projects: (1) enhancement in productivity, (2) switchover from low-income crops to high-income crops, (3) rises in land price, and (4) lower fluctuation in production.

Control system modeling of stock management for civil infrastructure

  • Abe, Masato
    • Smart Structures and Systems
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    • 제15권3호
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    • pp.609-625
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    • 2015
  • Management of infrastructure stock is essential in sustainability of society, and its analysis and optimization are studied in the light of control system modeling in this paper. At the first part of the paper, cost of stock management is analyzed based on macroscopic statistics on infrastructure stock and economical growth. Stock management burden relative to economy is observed to become larger at low economic growth periods in developed economies. Then, control system modeling of stock management is introduced and by augmenting maintenance actions as control input, dynamic behavior of stock is simulated and compared with existing time history statistics. Assuming steady state conditions, applicability of the model to cross sectional data is also demonstrated. The proposed model is enhanced so that both preventive and corrective maintenance can be included as system inputs, i.e., feedforward and feedback control inputs. Optimal management strategy to achieve specified deteriorated stock level with minimal cost, expressed in terms of preventive and corrective maintenance actions, is derived based on estimated parameter values for corrosion of steel bridges. Relative cost effectiveness of preventive maintenance is shown when target deteriorated stock level is lower.