1,799 research outputs found
Entrepreneurial orientation and international performance: the moderating effect of decision-making rationality
This research examines how entrepreneurial orientation (EO) influences international performance (IP) of the firm taking into account the moderating effect of decision-making rationality (DR) on the EO–IP association. Such an investigation is significant because it considers the interplay of strategic decision-making processes supported by the bounded rationality concept in the entrepreneurship field. Drawing from a study on activities of 216 firms in the United States and United Kingdom, the evidence suggests that DR positively moderates the EO–IP association. The findings suggest that managers can improve IP by combining EO with rational (analytical) processes in their strategic decisions
Transfer Length of Strands in Prestressed Concrete Piles
A top bar effect has been identified in prestressed concrete piles. The effect that this top bar effect has on the development of the prestressing strand is investigated. Strand transfer length is found to be proportional to the observed end slip. While the average transfer length of all strands in a section may satisfy the assumptions inherent in the ACI transfer length equation, due to the top bar effect, top-cast strand transfer lengths are considerably in excess of the ACI-calculated value. The flexural behavior of the pile, accounting for varying transfer lengths through its section, is investigated. Finally, recommendations for in-plant testing and acceptance criteria for prestressed strand bond quality are proposed
Top Bar Effects in Prestressed Concrete Piles
The top bar effect in reinforced concrete is a widely recognized phenomenon. Currently, the ACI Building Code prescribes a 30% increase in the development length of top cast reinforcing bars. No such provision is required for strands in prestressed concrete members. In this paper, the top bar effect for prestressing strands is introduced. Parameters affecting top bar phenomena in prestressed concrete piles are identified, and strategies for reducing this effect are presented. Finally, for the first time, the application of a top bar effect factor for prestressed concrete development length calculations, similar to the one applied in reinforced concrete structural elements, is proposed
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Full tomographic reconstruction of 2D vector fields using discrete integral data
Vector field tomography is a field that has received considerable attention in recent decades. It deals with the problem of the determination of a vector field from non-invasive integral data. These data are modelled by the vectorial Radon transform. Previous attempts at solving this reconstruction problem showed that tomographic data alone are insufficient for determining a 2D band-limited vector field completely and uniquely. This paper describes a method that allows one to recover both components of a 2D vector field based only on integral data, by solving a system of linear equations. We carry out the analysis in the digital domain and we take advantage of the redundancy in the projection data, since these may be viewed as weighted sums of the local vector field's Cartesian components. The potential of the introduced method is demonstrated by presenting examples of vector field reconstruction
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Sampling bounds for 2-D vector field tomography
The tomographic mapping of a 2-D vector field from line-integral data in the discrete domain requires the uniform sampling of the continuous Radon domain parameter space. In this paper we use sampling theory and derive limits for the sampling steps of the Radon parameters, so that no information is lost. It is shown that if Δx is the sampling interval of the reconstruction region and xmax is the maximum value of domain parameter x, the steps one should use to sample Radon parameters ρ and θ should be: Δρ≤ Δx/√2 and Δθ≤Δx/((√2+2)|xmax|). Experiments show that when the proposed sampling bounds are violated, the reconstruction accuracy of the vector field deteriorates. We further demonstrate that the employment of a scanning geometry that satisfies the proposed sampling requirements also increases the resilience to noise
A Framework for Applying Health Technology Assessment in Cyprus: Thoughts, Success Stories, and Recommendations
AbstractObjectivesHealth care decision making, assessment, and procurement of medicines is a complex, human resource–demanding, and time-consuming process. A thorough evaluation of all factors involved is necessary to optimize the process. The objective of this study was to describe and analyze the current stage of health technology assessment (HTA) in Cyprus.MethodsLiterature research and private communication with all involved parties and competent authority. Moreover, data, decisions, and recommendations of the Drug’s Committee were used.ResultsCyprus is a latecomer in this field. HTA has entered a growing phase after the 2007 reform. It has not reached its full potential, and the current state is applicable only to the public sector, because of the nonexistence of a national health system. Therefore, this poses both a great challenge and a great barrier considering maximization of the value of money spent and health access equity.ConclusionsThere is definitely enough space and clear necessity for further dissemination, and early successes indicate that steps should be taken toward the introduction of an HTA procedure that will cover both private and public sectors. The introduction of a national health system will further enhance the uptake of HTA, optimize the process, and use the common knowledge strategy for evidence-based decision making
Excessive Strand End Slip in Prestressed Piles
This paper presents the results of a research project that investigated excessive strand end slip observed recently in some prestressed piles. From measurements taken in the field, it is apparent that the problem o excessive initial strand slip is independent of pile shape and size. Strand end slip is evident in piles of different manufacturers in different states in the Southeast. Excessive strand end slip was found in both the top and bottom of the cross section of the piles, although the top portion of the cross section generally exhibited much higher initial slip. Several preventive measures can be adopted to reduce the excessive strand end slip. These preventive measures include: a) proper concrete mixture proportioning to reduce top bar effect; b) use of higher-strength concrete with the lowest possible slump and setting time; c) assessment of the condition of the strands prior to installation to insure excellent bond characteristics; d) gradual release of prestress, with an optimal release sequence; and e) use of adequate vibration to ensure consolidation. The strand end slip measured at five prestressing plants in the Southeast is considerably higher than the allowable end slip and is expected to affect the pile performance. If the strand slip theory is adopted, the strand development length increases substantially due to the excessive strand end slip. A top bar effect factor similar to the one used in reinforced concrete design is recommended. To maintain the excellent quality of precast and prestressed concrete products, manufacturers should adopt a dynamic quality control process that follows the rapid changes in the industry. More tests are necessary to ensure excellent quality, such as the Moustafa or an equivalent test, to assess the bond capabilities of the strands, end slip measurements, and direct measurement of the transfer length. Installation of piles should proceed in a manner to alleviate the top bar effects by placing piles alternately in their best and worst directions
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