• Title/Summary/Keyword: Impact Analyses

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Acceleration amplification characteristics of embankment reinforced with rubble mound

  • Jung-Won Yun;Jin-Tae Han;Jae-Kwang Ahn
    • Geomechanics and Engineering
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    • v.36 no.2
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    • pp.157-166
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    • 2024
  • Generally, the rubble mound installed on the slope embankment of the open-type wharf is designed based on the impact of wave force, with no consideration for the impact of seismic force. Therefore, in this study, dynamic centrifuge model test results were analyzed to examine the acceleration amplification of embankment reinforced with rubble mound under seismic conditions. The experimental results show that when rubble mounds were installed on the ground surface of the embankment, acceleration response of embankment decreased by approximately 22%, and imbalance in ground settlement decreased significantly from eight to two times. Furthermore, based on the experimental results, one-dimensional site response (1DSR) analyses were conducted. The analysis results indicated that reinforcing the embankment with rubble mound can decrease the peak ground acceleration (PGA) and short period response (below 0.6 seconds) of the ground surface by approximately 28%. However, no significant impact on the long period response (above 0.6 seconds) was observed. Additionally, in ground with lower relative density, a significant decrease in response and wide range of reduced periods were observed. Considering that the reduced short period range corresponds to the critical periods in the design response spectrum, reinforcing the loose ground with rubble mound can effectively decrease the acceleration response of the ground surface.

Detecting artefacts in analyses of extreme wind speeds

  • Cook, Nicholas J.
    • Wind and Structures
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    • v.19 no.3
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    • pp.271-294
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    • 2014
  • The impact of artefacts in archived wind observations on the design wind speed obtained by extreme value analysis is demonstrated using case studies. A signpost protocol for detecting candidate artefacts is described and its performance assessed by comparing results against previously validated data. The protocol targets artefacts by exploiting the serial correlation between observations. Additional "sieve" algorithms are proposed to identify types of correctable artefact from their "signature" in the data. In extreme value analysis, artefacts displace valid observations only when they are larger, hence always increase the design wind speed. Care must be taken not identify large valid values as artefacts, since their removal will tend to underestimate the design wind speed.

Financial transfers from elderly parents to their adult children (노부모의 금전이전 행동에 관한 연구)

  • 고선강
    • Journal of Family Resource Management and Policy Review
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    • v.6 no.2
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    • pp.53-64
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    • 2002
  • The main purposes of this study are to examine the impact of parent's and child's incomes on financial transfers from elderly parents to their adult children, and to study other factors influencing financial transfers from parents to children. Analyzing data from the Wisconsin Longitudinal Study, which provides long-term observations of financial transfers, the current study finds strong positive effects of parent's income on financial transfers from parents to their adult children. In terms of determinants of financial transfers, the results of multivariate logistic regression analyses suggest that child's education child's marital status, and sibling size are statistically significant determinants of parent-to-child financial transfers.

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항공사 시장성과의 결정요인 분석

  • Kim, Gyeong-Suk
    • The Journal of Aerospace Industry
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    • s.66
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    • pp.45-56
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    • 2003
  • Airlines service is very important so as to overcome the rapid environmental changes of the air transportation market at home and abroad. Author investigates the impact of Determinants on the performance of airlines in all the world. Three variables of performance measurement were used : revenue, net profit, and passengers. Data analyses were based on service ranking, financial and passenger information of the world's top 50 Airlines collected from Business Traveller, World Air Transport Statistics and Airline Business. The findings of this study could be summarized as follows : Service ranking was not related to the airlines performances such as revenue, net profit, passengers and so fourth. But airlines size(employees, fleet size) was related to the airlines performances such as passengers and revenue passenger.

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A Conceptual Study of Rail Renaissance and Sustainability (철도 르네상스와 지속가능성)

  • Moon Dae-Seop
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1646-1651
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    • 2004
  • This primary study describes some proposition of restoration and rehabilitation of rail station and station impact area for efficient use. Therefore, I reviewed the functions and roles about rail station and other railway facilities related with urban structures and development, and also analysed the case studies about realignment of rail station, and then, suggested primary management plan of efficient railway installation. This study has some bounds and limits owing to the descriptive reviews but not detailed analyses. Hereafter, I am planning to consider the management plan for efficient railway installation use as coinciding with specific city characteristic and comprehensive plan such as rearrangement of the station.

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Economic Impact of Government Archives (공공기록관의 경제적 효과)

  • Yakel, Elizabeth
    • Journal of Korean Society of Archives and Records Management
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    • v.12 no.3
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    • pp.155-176
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    • 2012
  • Economic impact analyses have not been widely conducted in archives. This article reports on a two parallel surveys in the US and Canada to assess the economic impact of government archives (state, provincial, territorial, county, and municipal). The surveys utilize indirect measures of economic impact. Responses from 2,534 people in 66 archives were analyzed. Findings indicate that archives were the primary reason that respondents visited an area and that visitors exhibit specific patterns of visiting the archives in conjunction with other cultural organizations in an area. Furthermore, while many respondents used local eateries, fewer rented lodgings or spent money on theater or sporting events. As a result, the archives participating in this survey did have a modest impact on local economies. The article concludes by discussing three major questions about the evaluation of the economic impact of archives which were raised by the findings: 1) Are indirect measures the most appropriate means of assessing economic impact in archives or should archives employ direct measures as used by public libraries? 2) How should government archives formulate their value proposition and should those value propositions focus on other aspects of archives' impact, such as the social impact, to demonstrate archives' important role in society? and 3) Since visitors exhibited distinct visitation patterns, should archives work more with these other aligned organizations and work on larger forms of collective impact that benefit the entire cultural heritage sector in an area?

The Effects of Social Capital, Target Costing and IT Infrastructure on Knowledge Management Processes (지식경영 과정들에 대한 사회적 자본, 원가기획시스템과 정보기술 하부구조의 영향)

  • Choi, Jong-Min
    • Journal of the Korean Operations Research and Management Science Society
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    • v.35 no.2
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    • pp.89-114
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    • 2010
  • This study empirically investigated the effects of the target costing system as well as information technology(IT) infrastructure on the knowledge management processes(i.e., socialization, externalization, combination and internalization) and the performance of a firm. This study also examined an impact of the social capital(i.e., inter-departmental communication, trust, cooperation and integration) on the adoption and development of the target costing and the IT infrastructure. The results of this study showed that inter-departmental communication, trust and integration have a significant positive impact on the adoption of the target costing. It was also found that the effects of inter-departmental communication and integration on the development of storage and transfer infrastructure are significant and positive. However, in the adoption of search infrastructure, only the impact of inter-departmental integration was significant. The results of regression analyses presented that the target costing has significant influence on the four processes of knowledge management. It was also observed that the effects of storage and transfer infrastructure on combination are significant and positive. In search infrastructure, the impact on combination and internalization was significant. According to the results of this study, it was found that when the adoption level of the target costing is high, search infrastructure mainly affects the three processes(i.e., socialization, combination and internalization). However, under a low adoption level of the target costing, the impact of storage and transfer infrastructure on the whole processes was significant and positive. Thus, it is assumed that storage and transfer infrastructure complements a low level of the target costing adoption through the active transfer and sharing of explicit and tacit knowledge.

Development of a Probabilistic Safety Assessment Framework for an Interim Dry Storage Facility Subjected to an Aircraft Crash Using Best-Estimate Structural Analysis

  • Almomani, Belal;Jang, Dongchan;Lee, Sanghoon;Kang, Hyun Gook
    • Nuclear Engineering and Technology
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    • v.49 no.2
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    • pp.411-425
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    • 2017
  • Using a probabilistic safety assessment, a risk evaluation framework for an aircraft crash into an interim spent fuel storage facility is presented. Damage evaluation of a detailed generic cask model in a simplified building structure under an aircraft impact is discussed through a numerical structural analysis and an analytical fragility assessment. Sequences of the impact scenario are shown in a developed event tree, with uncertainties considered in the impact analysis and failure probabilities calculated. To evaluate the influence of parameters relevant to design safety, risks are estimated for three specification levels of cask and storage facility structures. The proposed assessment procedure includes the determination of the loading parameters, reference impact scenario, structural response analyses of facility walls, cask containment, and fuel assemblies, and a radiological consequence analysis with dose-risk estimation. The risk results for the proposed scenario in this study are expected to be small relative to those of design basis accidents for best-estimated conservative values. The importance of this framework is seen in its flexibility to evaluate the capability of the facility to withstand an aircraft impact and in its ability to anticipate potential realistic risks; the framework also provides insight into epistemic uncertainty in the available data and into the sensitivity of the design parameters for future research.

Safety assessment of Generation III nuclear power plant buildings subjected to commercial aircraft crash Part I: FE model establishment and validations

  • Liu, X.;Wu, H.;Qu, Y.G.;Xu, Z.Y.;Sheng, J.H.;Fang, Q.
    • Nuclear Engineering and Technology
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    • v.52 no.2
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    • pp.381-396
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    • 2020
  • Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part I, finite element (FE) models establishment and validations for both the aircrafts and NPP buildings are performed. (i) Airbus A320 and A380 aircrafts are selected as the representative medium and large commercial aircrafts, and the corresponding fine FE models including the skin, beam, fuel and etc. are established. By comparing the numerically derived impact force time-histories with the existing published literatures, the rationality of aircrafts models is verified. (ii) Fine FE model of the Chinese Zhejiang Sanao NPP buildings is established, including the detailed structures and reinforcing arrangement of both the containment and auxiliary buildings. (iii) By numerically reproducing the existing 1/7.5 scaled aircraft model impact tests on steel plate reinforced concrete (SC) panels and assessing the impact process and velocity time-history of aircraft model, as well as the damage and the maximum deflection of SC panels, the applicability of the existing three concrete constitutive models (i.e., K&C, Winfrith and CSC) are evaluated and the superiority of Winfrith model for SC panels under deformable missile impact is verified. The present work can provide beneficial reference for the integral aircraft crash analyses and structural damage assessment in the following two parts of this paper.

Experiments on the Denting Damage and Residual Strength of Stiffened Plates (보강판의 국부변형 손상과 잔류 강도의 실험연구)

  • Park, Sang-Hyun;Shin, Hyun Kyoung;Kang, Eungsoon;Cho, Sang-Rai;Jang, Yong-Su;Baek, Nam-Ki;Park, Dong-Ki
    • Journal of the Society of Naval Architects of Korea
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    • v.57 no.4
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    • pp.182-190
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    • 2020
  • This study reports a series of drop impact tests performed to generate denting damages on stiffened plates and their residual ultimate strength tests under axial compression. The models were fabricated of general structural steel, and each model has six longitudinal stiffeners and two transverse frames. Among six fabricated models, four were damaged, and two were left intact for reference. To investigate the effects of collision velocity and impact location on the extent of damage, the drop height and the impact location were changed in each impact test. After performing the collision tests, the ultimate axial compression tests were conducted to investigate the residual strengths of the damaged stiffened plates. Finite element analyses were also carried out using a commercial package Abaqus/Explicit. The material properties obtained from a quasi-static tensile tests were used, and the strain-rate sensitivity was considered. After importing the collision simulation results, the ultimate strength calculations were carried out and their results were compared with the test data for the validation of the finite element analysis method.