Dynamic Behavior of Precast Concrete Beam-Column Sub-Assemblages with High Performance Connections Subjected to Sudden Column Removal Scenario

Unbonded posttensioned precast concrete (UPPC) structure has shown its excellent aseismic performance in laboratory tests and earthquake investigation. However, the progressive collapse behavior of UPPC subjected to column removal scenario is still unclear. To fill this knowledge gap, two 1/2 scaled UPPC beam-column sub-assemblages were tested under a penultimate column removal scenario. The dynamic test results indicated that UPPC sub-assemblages have desirable load redistribution capacity to mitigate progressive collapse. The failure modes of the sub-assemblages observed in dynamic test were quite similar to that in static counterparts

Study on collapse mechanism of steel frame with CFST-columns under column-removal scenario

The design of structure against progressive collapse has tended towards more quantitative design where utilizing catenary action becomes essential. In this paper, a single internal column removal test was conducted for a 1/3 scale 4-bay steel frame with concrete-filled steel tubular (CFST) columns. The anti-collapse mechanism of the frame under the scenario of column loss is discussed. Both FE model and simplified analytical model are developed to investigate the behavior of steel frame with CFST columns in resisting progressive collapse. The accuracy of the two models is verified through the experimental results. The anti-collapse measures of the proposed model are sensitive to the modeling techniques used to simulate the CFST columns. A method based on the energy equivalence is used to evaluate the dynamic behavior of the frame. The results show that the DAF (dynamic amplification factor) value of 2.0 which is recommended by DoD provision in linear static analysis is reasonable. However the mobilization of “catenary action” which is not considered in DoD provision would increase the DAF value as currently given in DoD

The effect of provider- and workflow-focused strategies for guideline implementation on provider acceptance

<p>Abstract</p> <p>Background</p> <p>The effective implementation of clinical practice guidelines (CPGs) depends critically on the extent to which the strategies that are deployed for implementing the guidelines promote provider acceptance of CPGs. Such implementation strategies can be classified into two types based on whether they primarily target providers (<it>e.g.</it>, academic detailing, grand rounds presentations) or the work context (<it>e.g.</it>, computer reminders, modifications to forms). This study investigated the independent and joint effects of these two types of implementation strategies on provider acceptance of CPGs.</p> <p>Methods</p> <p>Surveys were mailed to a national sample of providers (primary care physicians, physician assistants, nurses, and nurse practitioners) and quality managers selected from Veterans Affairs Medical Centers (VAMCs). A total of 2,438 providers and 242 quality managers from 123 VAMCs participated. Survey items measured implementation strategies and provider acceptance (<it>e.g.</it>, guideline-related knowledge, attitudes, and adherence) for three sets of CPGs--chronic obstructive pulmonary disease, chronic heart failure, and major depressive disorder. The relationships between implementation strategy types and provider acceptance were tested using multi-level analytic models.</p> <p>Results</p> <p>For all three CPGs, provider acceptance increased with the number of implementation strategies of either type. Moreover, the number of workflow-focused strategies compensated (contributing more strongly to provider acceptance) when few provider-focused strategies were used.</p> <p>Conclusion</p> <p>Provider acceptance of CPGs depends on the type of implementation strategies used. Implementation effectiveness can be improved by using both workflow-focused as well as provider-focused strategies.</p

Numerical Investigation on Load Redistribution Capacity of Flat Slab Substructures to Resist Progressive Collapse

To study the load redistribution capacity of reinforced concrete (RC) flat slab structures subjected to a middle column loss scenario, high fidelity finite element (FE) models were built using commercial software LS-DYNA. The numerical models were validated by experimental results. It is found that the continuous surface cap model (CSCM) with an erosion criterion considering both the maximum principal and shear strain could effectively predict the punching shear failure at slab13 column connections. The validated FE models were employed to investigate the effect of boundary conditions, amount of integrity reinforcement, and slab thickness on the load redistribution capacity of flat slab structures. Furthermore, multi-story RC flat slab substructures were built to capture the load redistribution behavior of different floors. Parametric studies indicate that ignoring the constraints from surrounding slabs may underestimate the load redistribution capacity of the flat slab substructures. Therefore, it is suggested that in future numerical or experimental studies, rigid horizontal constraints should be applied at the slab edge of the substructure to well represent the constraints from surrounding slabs. In addition, it is also found that the amount of integrity reinforcement would significantly affect the post-punching performance of flat slab structures. It is suggested that the minimum integrity reinforcement ratio should be 0.63 %

The role of space in the security and defence policy of Turkey. A change in outlook: Security in space versus security from space

Space and security domains are strongly related with each other. Nowadays, space is an indispensable part of security and defence policy, and it is increasingly becoming a critical infrastructure for strategic Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR) systems. However, space is vulnerable itself to the new space threats. This study reviews the current and near future space role in Turkey's security and defence policy and aims to address the threats against space based capabilities. To provide security from space, space based systems shall themselves need to be secure in space to warrant the security. The concept of security from space starts with space security, in other words the security in space. This paper also highlights the emerging technological opportunities for these space threats to be secure in space in order to provide the security from space. According to the relevant taxonomy, a categorized opportunity proposal for more robust and resilient space/satellite projects' architecture is proposed for Turkey

Valuation of ecosystem services to inform management of multiple-use landscapes

Public agencies worldwide are increasingly adopting an ecosystem service framework to manage lands serving multiple uses. Yet, reliable, practical, and well-tailored methods remain a major limitation in moving from conceptual to actionable approaches. Together with one of the largest federal land managing agencies, we co-develop and co-demonstrate an ecosystem services approach tailored to specific decisions, through a process with potentially widespread relevance. With the U.S. Department of Defense (DoD), we focus on balancing military training with biodiversity and resource conservation under both budgetary and land-use pressures at a representative installation. In an iterative process of co-design and application, we define, map, and quantify multiple ecosystem services under realistic management options. Resource management budget emerges as a major determinant of the degree to which managers can sustain both necessary training environments – a DoD-specific ecosystem service – and a prairie ecosystem with species of conservation concern. We also found clear tradeoffs between training intensity and forest-related services. Our co-developed approach brings otherwise hidden values and tradeoffs to the fore in a balanced way that can help public agencies safeguard priority services under potentially conflicting uses and budget limitations

On the integration of model-based feature information in Product Lifecycle Management systems

[EN] As CAD models continue to become more critical information sources in the product's lifecycle, it is necessary to develop efficient mechanisms to store, retrieve, and manage larger volumes of increasingly complex data. Because of their unique characteristics, 3D annotations can be used to embed design and manufacturing information directly into a CAD model, which makes models effective vehicles to describe aspects of the geometry or provide additional information that can be connected to a particular geometric element. However, access to this information is often limited, difficult, and even unavailable to external applications. As model complexity and volume of information continue to increase, new and more powerful methods to interrogate these annotations are needed. In this paper, we demonstrate how 3D annotations can be effectively structured and integrated into a Product Lifecycle Management (PLM) system to provide a cohesive view of product-related information in a design environment. We present a strategy to organize and manage annotation information which is stored internally in a CAD model, and make it fully available through the PLM. Our method involves a dual representation of 3D annotations with enhanced data structures that provides shared and easy access to the information. We describe the architecture of a system which includes a software component for the CAD environment and a module that integrates with the PLM server. We validate our approach through a software prototype that uses a parametric modeling application and two commercial PLM packages with distinct data models.This work was supported by the Spanish Ministry of Economy and Competitiveness and the FEDER Funds, through the ANNOTA project (Ref. TIN2013-46036-C3-1-R).Camba, J.; Contero, M.; Company, P.; Pérez Lopez, DC. (2017). On the integration of model-based feature information in Product Lifecycle Management systems. International Journal of Information Management. 37(6):611-621. https://doi.org/10.1016/j.ijinfomgt.2017.06.002S61162137

Seismic Forces in Ancillary Components Supported on Piers and Wharves

This paper presents a simple procedure to estimate seismic forces in ancillary components (secondary systems) supported on marine structures such as piers, wharves, and marine oil terminals (primary systems). Since many such marine structures can be idealized as single-degree-of-freedom (SDOF) systems, this study uses a simple linear-elastic model with two DOF, one representing the marine structure and the other representing the ancillary component. This study shows that acceleration at the base of the secondary system is approximately equal to spectral acceleration at the fundamental period of the primary system. It also proposes a formula, which is an improvement over current ASCE 7-10 recommendations, to estimate acceleration amplification in the secondary system due to its flexibility when mass and period ratios of the secondary and primary systems are known. The procedure in this paper is strictly applicable to marine structures for which primarily a single mode contributes to seismic response

Predicting implementation from organizational readiness for change: a study protocol

<p>Abstract</p> <p>Background</p> <p>There is widespread interest in measuring organizational readiness to implement evidence-based practices in clinical care. However, there are a number of challenges to validating organizational measures, including inferential bias arising from the halo effect and method bias - two threats to validity that, while well-documented by organizational scholars, are often ignored in health services research. We describe a protocol to comprehensively assess the psychometric properties of a previously developed survey, the Organizational Readiness to Change Assessment.</p> <p>Objectives</p> <p>Our objective is to conduct a comprehensive assessment of the psychometric properties of the Organizational Readiness to Change Assessment incorporating methods specifically to address threats from halo effect and method bias.</p> <p>Methods and Design</p> <p>We will conduct three sets of analyses using longitudinal, secondary data from four partner projects, each testing interventions to improve the implementation of an evidence-based clinical practice. Partner projects field the Organizational Readiness to Change Assessment at baseline (n = 208 respondents; 53 facilities), and prospectively assesses the degree to which the evidence-based practice is implemented. We will conduct predictive and concurrent validities using hierarchical linear modeling and multivariate regression, respectively. For predictive validity, the outcome is the change from baseline to follow-up in the use of the evidence-based practice. We will use intra-class correlations derived from hierarchical linear models to assess inter-rater reliability. Two partner projects will also field measures of job satisfaction for convergent and discriminant validity analyses, and will field Organizational Readiness to Change Assessment measures at follow-up for concurrent validity (n = 158 respondents; 33 facilities). Convergent and discriminant validities will test associations between organizational readiness and different aspects of job satisfaction: satisfaction with leadership, which should be highly correlated with readiness, versus satisfaction with salary, which should be less correlated with readiness. Content validity will be assessed using an expert panel and modified Delphi technique.</p> <p>Discussion</p> <p>We propose a comprehensive protocol for validating a survey instrument for assessing organizational readiness to change that specifically addresses key threats of bias related to halo effect, method bias and questions of construct validity that often go unexplored in research using measures of organizational constructs.</p