• Title/Summary/Keyword: Impact values

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Optimum stiffness values for impact element models to determine pounding forces between adjacent buildings

  • Jaradat, Yazan;Far, Harry
    • Structural Engineering and Mechanics
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    • v.77 no.2
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    • pp.293-304
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    • 2021
  • Structural failure due to seismic pounding between two adjacent buildings is one of the major concerns in the context of structural damage. Pounding between adjacent structures is a commonly observed phenomenon during major earthquakes. When modelling the structural response, stiffness of impact spring elements is considered to be one of the most important parameters when the impact force during collision of adjacent buildings is calculated. Determining valid and realistic stiffness values is essential in numerical simulations of pounding forces between adjacent buildings in order to achieve reasonable results. Several impact model stiffness values have been presented by various researchers to simulate pounding forces between adjacent structures. These values were mathematically calculated or estimated. In this study, a linear spring impact element model is used to simulate the pounding forces between two adjacent structures. An experimental model reported in literature was adopted to investigate the effect of different impact element stiffness k on the force intensity and number of impacts simulated by Finite Element (FE) analysis. Several numerical analyses have been conducted using SAP2000 and the collected results were used for further mathematical evaluations. The results of this study concluded the major factors that may actualise the stiffness value for impact element models. The number of impacts and the maximum impact force were found to be the core concept for finding the optimal range of stiffness values. For the experimental model investigated, the range of optimal stiffness values has also been presented and discussed.

An Experimental Study or the Prediction Method of Floor Impact Sound Insulation Performance in Apartment House Using Impedance Method(II) (임피던스법을 이용한 공동주택 바닥 충격음 차음성능 예측방법에 관한 실험 적 연구(II) - 경량 표준충격원을 중심으로 -)

  • 김재수;장길수;김선우
    • Journal of KSNVE
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    • v.2 no.1
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    • pp.21-31
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    • 1992
  • In the previous paper, we report a practical floor impact sound level prediction method for a heavyweight impact source(Tire), soft impact source such as children jumping and running. According to these results, the calculated value and the measured value correspond comparatively well, regardless of differences in the floor structures. And the floor impact sound for a heavyweight impact source, soft source was strongly influenced by structural factors such as floor slab stiffness and peripheral support conditions. But the floor impact sound for a light impact source (Tapping machine), hard impact source was influenced by resilient layers, composed of multi-layer in floor structures. Thus, In this paper, 4 actual floor structures, all with differing resilient layers, were calculated using impedance method. When these calculation values were compared with the measured values, approximately all the values fell with one rank of the sound insulation grade, reference curve(L curve) by the JIS standard. So, a sample of measured values and calculated values from floor structures is presented to show the accuracy and appropriateness of the impedance method in domestic.

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Dynamic Analysis of Concrete Rigid Barriers by Computer Simulation (컴퓨터 시뮬레이션에 의한 콘크리트 교량난간의 동적거동 분석)

  • 김재일;안재석;박진환;우광성
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.04a
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    • pp.217-224
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    • 2004
  • This paper proposed a new impact equation by analyzing the form of the proposal section 1 and section 2 proposed by Korea Highway Corporation, F-type, NJ-type and SS-type with HVOSM program Because the impact equation proposed by Ministry Construction & Transportation(1992) considered an only impact velocity, the values of impact loads calculated by HVOSM program are 21.5∼44 times as large as those using equation of MCT. The values of HVOSM program are 1.4 times as large as those of Olson's model because Olson's equation consider impact vehicle, impact velocity and impact angle. But, it does not consider geometric characters, while HVOSM program considers characters. Considering the shapes of sections and the conditions of colliding, HVOSM program can calculate imuact load. As Multiple Regression Analysis is conducted with the calculated values, the R² values of the proposed equations are 0.984 in SB1∼SB3 and 0.958 in SB4∼SB6. After all, the equation proposed in this study have better results than Olson's equation.

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Impact of Open Access Models on Citation Metrics

  • Razumova, Irina K.;Kuznetsov, Alexander
    • Journal of Information Science Theory and Practice
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    • v.7 no.2
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    • pp.23-31
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    • 2019
  • We report results of selection-bias-free approaches to the analysis of the impact of open access (OA) models on citation metrics. We studied reference groups of Gold and Green OA articles and the group of non-OA (Paywall) articles with the new functionality of the Web of Science Core Collection database, the InCites platform of Clarivate Analytics, and the Dimensions database of Digital Science. For each reference group we obtained the values of the percent of cited articles and citation impact and their dependence on the depth of the citation period. Different research fields were analyzed in two schemas of the InCites platform. We report the higher values and growth rates of the citation metrics: citation impact and %Cited, in the OA reference groups over the Paywall group. The Green OA articles demonstrate the highest values of citation metrics among all the OA models. Dependence of the value of citation impact on citation period follows linear law with R2 values close to 0.9-1.0. The overall annual growth rates of citation impact of the Green OA, Gold OA, and the Paywall articles, k equal, respectively, 3.6, 2.4, and 1.4 in Dimensions and 4.6, 3.6, and 2.3 in the Web of Science Core Collection. We suppose that earlier results reported for the articles in pure OA journals vs. articles in Paywall journals were affected by the high citation impact of the Green and Hybrid OA articles that could not be elucidated in the Paywall journals at that time.

Analyzing the Impact of Value Satisfaction on Behavioral Intention to Use E-Resources

  • Kumar, Vinod;Garg, Ruchi Jain;Vandana, Vandana;Zia, Adil
    • Journal of Information Science Theory and Practice
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    • v.10 no.3
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    • pp.1-14
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    • 2022
  • The present study investigates the impact of perceived value metrics in driving satisfaction and behavioral intention to use e-resource among its users. Utilitarian, hedonic, uniqueness, epistemic, and economic are key values selected for the purpose of investigation in the study. This empirical study is carried out through a survey and responses have been analyzed using structural equation modelling. The target group is selected by means of simple random sampling (users of e-resources in selected business schools). Findings of the study reveal that utilitarian values, hedonic values, epistemic values, and uniqueness values have a significant impact on the usage intention of e-resources; however, economic values reflect an insignificant relationship to intention to use e-resources. The study is a distinctive piece of work on investigating the most and the least significant value(s) associated with satisfaction and usage intentions of e-resources.

Aesthetic Value of Korean National Parks' Landscape: Its Appreciation and Protection Strategies (국립공원 경관 가치의 증진방안)

  • Park, Kyeong
    • Journal of Environmental Impact Assessment
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    • v.12 no.5
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    • pp.369-382
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    • 2003
  • Natural resources managers have considered the landscape without detailed consideration of aesthetic values of the landscape and geomorphological significance of unique landforms. Since EIA system was introduced in 1981, values associated with landscape protection have been neglected at best compared with those values traditionally attributed to environmental protection, including clean air, water quality and species protection. Black top highways are being built without consideration of harmful effects to the sea cliffs. Sea walls and tetrapod are being installed to protect the coastal towns and fish markets for tourist. However, beach itself are experiencing accelerated erosion due to the shortage of proper coastal engineering expertise. Hotels and condominiums are under construction on a massive scale around the national parks, which substitute the scenic ridges with concrete profiles. To protect the scenic beauty of national parks, their design and construction material should be more harmonious with the surroundings. Therefore, visual impact assessment should be applied both within the national park boundary and beyond to enhance the aesthetic values of national parks.

Safety Evaluation of Korean New Car Assessment Program - Side Impact (자동차 측면 충돌 안전도 평가 분석)

  • Shin, Jaeho;Yong, Gee Joong
    • Journal of Auto-vehicle Safety Association
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    • v.6 no.2
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    • pp.12-17
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    • 2014
  • The number of vehicle accidents related to the side impact has increased since 1990 in Korea, thus the side impact test has been performed as one of the major vehicle evaluations of the Korean New Car Assessment Program(KNCAP) in 2003. A total of 77 vehicles of eight different types(compact, small, semi-midsize, midsize, and large sedans and small, midsize, and large sports utility vehicles) were tested in side impact and side pole impact conditions. In this study, the head and thorax injury values(HICs and chest deflections) of the side impact tests performed between 2003 and 2013 were investigated in terms of vehicle type, test year, and test condition. The recent vehicles showed better safety performances(lower injury values) and similar injury patterns were obtained between side impact and pole side impact tests.

Estimation of impact characteristics of RC slabs under sudden loading

  • Erdem, R. Tugrul
    • Computers and Concrete
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    • v.28 no.5
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    • pp.479-486
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    • 2021
  • Reinforced concrete (RC) slabs are exposed to several static and dynamic effects during their period of service. Accordingly, there are many studies focused on the behavior of RC slabs under these effects in the literature. However, impact loading which can be more effective than other loads is not considered in the design phase of RC slabs. This study aims to investigate the dynamic behavior of two-way RC slabs under sudden impact loading. For this purpose, 3 different simply supported slab specimens are manufactured. These specimens are tested under impact loading by using the drop test setup and necessary measurement devices such as accelerometers, dynamic load cell, LVDT and data-logger. Mass and drop height of the hammer are taken constant during experimental study. It is seen that rigidity of the specimens effect experimental results. While acceleration values increase, displacement values decrease as the sizes of the specimens have bigger values. In the numerical part of the study, artificial neural networks (ANN) analysis is utilized. ANN analysis is used to model different physical dynamic processes depending upon the experimental variables. Maximum acceleration and displacement values are predicted by ANN analysis. Experimental and numerical values are compared and it is found out that proposed ANN model has yielded consistent results in the estimation of experimental values of the test specimens.

Analysis of Influence Factors on the Intention to Reuse O2O Service in Domestic Accommodation (국내 숙박 O2O서비스의 재이용 의도에 미치는 영향요인 분석)

  • Kim, Jung-Kyun;Kim, Injai
    • The Journal of Information Systems
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    • v.29 no.4
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    • pp.25-43
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    • 2020
  • Purpose The purpose of this study is to gradually increase the use of O2O services in recent years. It is a part of our daily lives, and accommodation/leisure is a part of the growing use of O2O services. Based on various prior research related to O2O service, the Commission intends to establish the justification and necessity of empirical research and to establish the relationship between O2O service impact factors and practical value, customer satisfaction and reuse intention. Design/methodology/approach This study analyzed what factors affected the intention of re-use of domestic accommodation O2O services. This research model was proposed based on the preceding research paper, and reliability, diversity, economics, leisure, safety and personalization were used as independent variables, practical value and customer satisfaction are parameters, and reuse intent is composed of dependent variables. Within the last year, users of domestic accommodation applications were selected as users who used domestic accommodation applications more than once, and data of domestic accommodation application users were analyzed using the SPSS 25.0 and AMOS 20.0 programs. Findings The results of this study show that economic efficiency, safety and personalization have significant effects on practical values in the relationship between O2O service impact factors and their impact on practical values. On the other hand, reliability, diversity and leisure were found to have no significant impact on practical values. In terms of O2O service impact factors and their impact on customer satisfaction, leisure and safety have significant effects on customer satisfaction. On the other hand, reliability, diversity, economics, and individualization have shown no significant impact on customer satisfaction. Practical values, parameters, customer satisfaction, and re-use intent, which are dependent variables, were also shown to have significant effects on practical values and customer satisfaction in the relationship.

Minimizing environmental impact from optimized sizing of reinforced concrete elements

  • Santoro, Jair F.;Kripka, Moacir
    • Computers and Concrete
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    • v.25 no.2
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    • pp.111-118
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    • 2020
  • The construction field must always explore sustainable ways of using its raw materials. Studying the environmental impact generated by reinforced concrete raw materials during their production and transportation can contribute to reducing this impact. This paper initially presents the carbon dioxide emissions from reinforced concrete raw materials, quantified per kilo of raw material and per cubic meter of concrete with different characteristic strengths, for southern Brazil. Subsequently, reinforced concrete elements were optimized to minimize their environmental impact and cost. It was observed that lower values of carbon dioxide emissions and cost savings are generated for less resistant concrete when the structural element is a beam, and that reductions in the cross section dimensions of the beams, sized based on the use of higher strength concrete, may not compensate for the increased environmental impact and costs. For the columns, the behavior differed, presenting lower values of carbon dioxide emissions and costs for higher concrete strengths. The proposed methodology, as well as the results obtained, can be used to support structural projects that have less impact on the environment.