• Title/Summary/Keyword: Critical infrastructure

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The responses of battered pile to tunnelling at different depths relative to the pile length

  • Mukhtiar Ali Soomro;Naeem Mangi;Dildar Ali Mangnejo;Zongyu Zhang
    • Geomechanics and Engineering
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    • v.35 no.6
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    • pp.603-615
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    • 2023
  • Population growth and urbanization prompted engineers to propose more sophisticated and efficient transportation methods, such as underground transit systems. However, due to limited urban space, it is necessary to construct these tunnels in close proximity to existing infrastructure like high-rise buildings and bridges. Battered piles have been widely used for their higher stiffness and bearing capacity compared to vertical piles, making them effective in resisting lateral loads from winds, soil pressures, and impacts. Considerable prior research has been concerned with understanding the vertical pile response to tunnel excavation. However, the three-dimensional effects of tunnelling on adjacent battered piled foundations are still not investigated. This study investigates the response of a single battered pile to tunnelling at three critical depths along the pile: near the pile shaft (S), next to the pile (T), and below the pile toe (B). An advanced hypoplastic model capable of capturing small strain stiffness is used to simulate clay behaviour. The computed results reveal that settlement and load transfer mechanisms along the battered pile, resulting from tunnelling, depend significantly on the tunnel's location relative the length of the pile. The largest settlement of the battered pile occurs in the case of T. Conversely, the greatest pile head deflection is caused by tunnelling near the pile shaft. The battered pile experiences "dragload" due to negative skin friction mobilization resulting from tunnel excavation in the case of S. The battered pile is susceptible to induced bending moments when tunnelling occurs near the pile shaft S whereas the magnitude of induced bending moment is minimal in the case of B.

Assessment of the Potential Impact of Climate Change on the Drought in Agricultural Reservoirs under SSP Scenarios (SSP 시나리오를 고려한 농업용 저수지의 이수측면 잠재영향평가)

  • Kim, Siho;Jang, Min-Won;Hwang, Syewoon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.66 no.2
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    • pp.35-52
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    • 2024
  • This study conducted an assessment of potential impacts on the drought in agricultural reservoirs using the recently proposed SSP (Shared Socioeconomic Pathways) scenarios by IPCC (Intergovernmental Panel on Climate Change). This study assesses the potential impact of climate change on agricultural water resources and infrastructure vulnerability within Gyeongsangnam-do, focusing on 15 agricultural reservoirs. The assessment was based on the KRC (Korea Rural Community Corporation) 1st vulnerability assessment methodology using RCP scenarios for 2021. However, there are limitations due to the necessity for climate impact assessments based on the latest climate information and the uncertainties associated with using a single scenario from national standard scenarios. Therefore, we applied the 13 GCM (General Circulation Model) outputs based on the newly introduced SSP scenarios. Furthermore, due to difficulties in data acquisiton, we reassessed potential impacts by redistributing weights for proxy variables. As a main result, with lower future potential impacts observed in areas with higher precipitation along the southern coast. Overall, the potential impacts increased for all reservoirs as we moved into the future, maintaining their relative rankings, yet showing no significant variability in the far future. Although the overall pattern of potential impacts aligns with previous evaluations, reevaluation under similar conditions with different spatial resolutions emphasizes the critical role of meteorological data spatial resolution in assessments. The results of this study are expected to improve the credibility and accuracy formulation of vulnerability employing more scientific predictions.

Development of Rainfall-runoff Analysis Algorithm on Road Surface (도로 표면 강우 유출 해석 알고리즘 개발)

  • Jo, Jun Beom;Kim, Jung Soo;Kwak, Chang Jae
    • Ecology and Resilient Infrastructure
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    • v.8 no.4
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    • pp.223-232
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    • 2021
  • In general, stormwater flows to the road surface, especially in urban areas, and it is discharged through the drainage grate inlets on roads. The appropriate evaluation of the road drainage capacity is essential not only in the design of roads and inlets but also in the design of sewer systems. However, the method of road surface flow analysis that reflects the topographical and hydraulic conditions might not be fully developed. Therefore, the enhanced method of road surface flow analysis should be presented by investigating the existing analysis method such as the flow analysis module (uniform; varied) and the flow travel time (critical; fixed). In this study, the algorithm based on varied and uniform flow analysis was developed to analyze the flow pattern of road surface. The numerical analysis applied the uniform and varied flow analysis module and travel time as parameters were conducted to estimate the characteristics of rainfall-runoff in various road conditions using the developed algorithm. The width of the road (two-lane (6 m)) and the slope of the road (longitudinal slope of road 1 - 10%, transverse slope of road 2%, and transverse slope of gutter 2 - 10%) was considered. In addition, the flow of the road surface is collected from the gutter along the road slope and drained through the gutter in the downstream part, and the width of the gutter was selected to be 0.5 m. The simulation results were revealed that the runoff characteristics were affected by the road slope conditions, and it was found that the varied flow analysis module adequately reflected the gutter flow which is changed along the downstream caused by collecting of road surface flow at the gutter. The varied flow analysis module simulated 11.80% longer flow travel time on average (max. 23.66%) and 4.73% larger total road surface discharge on average (max. 9.50%) than the uniform flow analysis module. In order to accurately estimate the amount of runoff from the road, it was appropriate to perform flow analysis by applying the critical duration and the varied flow analysis module. The developed algorithm was expected to be able to be used in the design of road drainage because it was accurately simulated the runoff characteristics on the road surface.

A study on the effect of ground conditions of room and pillar method on pillar and room strain (격자형 지하공간의 지반조건이 암주와 룸 변형률에 미치는 영향에 대한 연구)

  • Ham, Hyeon Su;Kim, Yong Kyu;Park, Chi Myeon;Lee, Chul Ho;Kim, YoungSeok
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.6
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    • pp.577-587
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    • 2021
  • Room and Pillar method is an underground facility construction method that maximizes the strength of the in-situ ground. In order to secure the safety of the underground space, it is necessary to secure the safety of the room actually used in addition to the safety of pillar of the room and Pillar method. In this study, the evaluation method for the safety of the room and rock pillar in the room and pillar method was studied through numerical analysis. Numerical analysis was performed for a total of 125 cases using ground conditions, pillar width, and room width as parameters, and the results were derived. As for the safety factor of the pillar, it was confirmed that the safety factor increased when the strength of the ground increased, and it was confirmed that the increment in the safety factor decreased when the width of the pillar was widened. The room strain was evaluated by applying the Critical strain. As the width of the pillar became narrower, the Critical strain was higher, and as the width of the room became smaller, the Critical strain was smaller. As a result of the correlation analysis between the safety factor of the pillar and the room strain, it was possible to derive the upper limit of the room strain that can secure the standard safety factor of the pillar according to the width of the pillar. It is judged that the results derived from this study can be used as a guideline to secure the safety of the room when the actual design is performed in consideration of the ground conditions and room width.

Assessment of Salt Damage for Upland-Crops in Dae-Ho Reclaimed Soil (대호 간척지 토양의 염농도별 밭작물의 염해 평가)

  • Lee, Seung-Heon;Yoo, Sun-Ho;Seol, Su-Il;An, Yeoul;Jung, Yeong-Sang;Lee, Sang-Mo
    • Korean Journal of Environmental Agriculture
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    • v.19 no.4
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    • pp.358-363
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    • 2000
  • This study was carried out to obtain the basic data for selecting the applicable crops in reclaimed land during desalinization period. A pot experiment was conducted with 5 different electrical conductivities of the saturated extracts $(ECe\;1,\;3,\;9,\;14,\;and\;16\;dS{\cdot}m^{-1})$ of soils taken from the Dae-Ho reclaimed tidal lands. Eight crops (Chinese cabbage, radish, tomato, red pepper, buckwheat, soybean, sesame, and green perilla) were grown for 37days. Plant height and number of leaves were surveyed on 2 and 4 weeks after seeding, and on harvest time (5 weeks). After harvest, dry weights of harvested crops were measured and soil chemical properties were analyzed. Emergence rates of crops were comparatively high except sesame. For sesame, there was no emergence at ECe over $3\;dS{\cdot}m^{-1}$. Growth and dry weight decreased significantly as increasing ECe. The ECe which decreased 50% of dry weight index were $14.2\;dS{\cdot}m^{-1}$ for radish, $11.4\;dS{\cdot}m^{-1}$ for Chinese cabbage, $10.2\;dS{\cdot}m^{-1}$ for red pepper, $8.9\;dS{\cdot}m^{-1}$ for buckwheat and green perilla, $8.6\;dS{\cdot}m^{-1}$ for soybean, and $8.9\;dS{\cdot}m^{-1}$ for tomato. At higher ECe that start the growth inhibition, increasing $1\;dS{\cdot}m^{-1}$ in ECe, 7.7, 6.5, 5.9, 5.6, 5.2, and 4.9% of dry weight decreased for buckwheat, green perilla, Chinese cabbage, radish, soybean, and tomato (red pepper), respectively. The critical value of ECe for crop survival except sesame was $15.4\;{\sim}\;23.1\;dS{\cdot}m^{-1}$.

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Determinants and Processes of IT Consolidation: A Case Study of Korean Conglomerates (IT 통합의 결정 요인과 과정: 국내 대기업들에 대한 사례 연구)

  • Zo, Hang-Jung;Song, Chan-Hoo;Han, Seung-Hun
    • Information Systems Review
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    • v.10 no.3
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    • pp.223-255
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    • 2008
  • This study explores the determinants and processes of IT consolidation of Korean conglomerates. Through an extensive analysis of cases, this study identifies the drivers, benefits and critical success factors of IT consolidation, and observes the transition of vision for the IT service subsidiaries in the conglomerates. The results show that most firms in this analysis have completed the organizational, physical, and logical consolidation of their IT resources, and currently some of them are preparing for the next stage of IT consolidation such as rational consolidation and virtualization. It is also found that the strategic factor was one of the most significant determinants in consolidating IT resources which leaded the transition of vision of the IT service firms in the conglomerates from "cost center" to "profit center". The results of this study can provide a fundamental and empirical basis for building a theory of IT consolidation, and be used as a valuable benchmarking model for the organizations which consider starting a project of IT consolidation.

Real-time Travel Time Estimation Model Using Point-based and Link-based Data (지점과 구간기반 자료를 활용한 실시간 통행시간 추정 모형)

  • Yu, Jeong-Whon
    • International Journal of Highway Engineering
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    • v.10 no.1
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    • pp.155-164
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    • 2008
  • It is critical to develop a core ITS technology such as real-time travel time estimation in order that the efficient use of the ITS implementation can be achieved as the ITS infrastructure and relevant facilities are broadly installed in recent years. The provision of travel time information in real-time allows travellers to make informed decisions and hence not only the traveller's travel utilities but also the road utilization can be maximized. In this paper, a hybrid model is proposed to combine VDS and AVI which have different characteristics in terms of space and time dimensions. The proposed model can incorporate the immediacy of VDS data and the reality of AVI data into one single framework simultaneously. In addition, the solution algorithm is made to have no significant computational burden so that the model can be deployable in real world. A set of real field data is used to analyze the reliability and applicability of the proposed model. The analysis results suggest that the proposed model is very efficient computationally and improves the accuracy of the information provided, which demonstrates the real-time applicability of the proposed model. In particular, the data fusion methodology developed in this paper is expected to be used more widely when a new type of traffic data becomes available.

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Rational Unification Scheme of Topographic Surveying and Cadastral Survey for the Synergistic Convergence Effect of GIS Industry (공간정보산업의 상승적 융합 효과 창출을 위한 측량과 지적의 합리적 통합방안)

  • Park, Hong Gi;Joo, Yong Jin;Min, Kwan Sik;Kim, Young Dan
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.1
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    • pp.69-78
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    • 2013
  • Recently, as GIS industry has substantially grown up, convergence between industries such as the application coverage of surveying and cadastral information is gradually on the increase. The new approach of convergence between topographic surveying and cadastral survey is indispensable to make the change of geospatial environment ready and to maximize the utilization of National Spatial Data Infrastructure(NSDI). The purpose of this paper is to seek the way of synergistic improvement in topographic surveying and cadastral survey in comprehensive aspects of national geospatial information. First, we reviewed policy environment to clearly establish aim of convergence and promising perspective of GIS industry policy, considering NSDI. In addition, we examined current state of administration (organization, human resource, service) and institution situation. We came up with interior ability and external policy environment as well as critical success factor for the synergistic convergence by using SWOT analysis. Lastly, we developed basic perspective of convergence and improvement model and concrete scheme for stakeholder to complementary make progress. We can come to conclusion that the convergence of topographic surveying and cadastral survey should be not only carried in macro outline of successful NSDI but also committed to completion and maintenance of GIS framework.

Performance and the Current Reform Process of Regional Development Agencies in England (영국 지역발전기구의 활동 성과와 구조재편 동향)

  • Lee, Jong-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.14 no.4
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    • pp.553-567
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    • 2011
  • Since their establishment in 1999, Regional Development Agencies in England have been a critical catalyst for sustaining regional development, by linking the central government and the region. Nevertheless, the new Coalition Government formed in May 2010 is to abolish RDAs and is to be replaced by Local Enterprise Partnerships(LEP). This article looks at the performance and the present reform process of the English Regional Development Agencies(RDA). It argues that RDAs have been a sort of laboratory to expose the possibility of realizing the new regionalist approach away from the government-centered approach. Nevertheless, the case of RDAs in England shows that the RDA model is less likely to be effective without substantial devolution. It shows that the extent to which RDAs contribute to the regional economy tends to be much higher in soft infra-centered projects, such as business supports and skills development, than physical infrastructure projects. It argues that the LEP model, which is to replace RDAs, is controversial, especially in terms of spatial boundary and financial structure.

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Impact of Community Health Care Resources on the Place of Death of Older Persons with Dementia in South Korea Using Public Administrative Big Data (공공 빅데이터를 이용한 치매 노인 사망장소의 결정요인: 지역보건의료자원의 영향)

  • Lim, Eunok;Kim, Hongsoo
    • Health Policy and Management
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    • v.27 no.2
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    • pp.167-176
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    • 2017
  • Background: This study aimed to analyze the impact of community health care resources on the place of death of older adults with dementia compared to those with cancer in South Korea, using public administrative big data. Methods: Based on a literature review, we selected person- and community-level variables that can affect older people's decisions about where to die. Data on place-of-death and person-level attributes were obtained from the 2013 death certification micro data from Statistics Korea. Data on the population and economic and health care resources in the community where the older deceased resided were obtained from various open public administrative big data including databases on the local tax and resident population statistics, health care resources and infrastructure statistics, and long-term care (LTC) insurance statistics. Community-level data were linked to the death certificate micro data through the town (si-gun-gu) code of the residence of the deceased. Multi-level logistic regression models were used to simultaneously estimate the impacts of community as well as individual-level factors on the place of death. Results: In both the dementia (76.1%) and cancer (87.1%) decedent groups, most older people died in the hospital. Among the older deceased with dementia, hospital death was less likely to occur when the older person resided in a community with a higher supply of LTC facility beds, but hospital death was more likely to occur in communities with a higher supply of LTC hospital beds. Similarly, among the cancer group, the likelihood of a hospital death was significantly lower in communities with a higher supply of LTC facility beds, but was higher in communities with a higher supply of acute care hospital beds. As for individual-level factors, being female and having no spouse were associated with the likelihood of hospital death among older people with dementia. Conclusion: More than three in four older people with dementia die in the hospital, while home is reported to be the place of death preferred by Koreans. To decrease this gap, an increase in the supply of end-of-life (EOL) care at home and in community-based service settings is necessary. EOL care should also be incorporated as an essential part of LTC. Changes in the perception of EOL care by older people and their families are also critical in their decisions about the place of death, and should be supported by public education and other related non-medical, social approaches.