Estimating the European Central Bank's "Extended Period of Time"

On July 4, 2013 the ECB Governing Council provided more specific forward guidance than in the past by stating that it expects ECB interest rates to remain at present or lower levels for an extended period of time. As explained by ECB President Mario Draghi this expectation is based on the Council’s medium-term outlook for inflation conditional on economic activity and money and credit. Draghi also stressed that there is no precise deadline for this extended period of time, but that a reasonable period can be estimated by extracting a reaction function. In this note, we use such a reaction function, namely the interest rate rule from Orphanides and Wieland (2013) that matches past ECB interest rate decisions quite well, to project the rate path consistent with inflation and growth forecasts from the survey of professional forecasters published by the ECB on August 8, 2013. This evaluation suggests an increase in ECB interest rates by May 2014 at the latest. We also use the Eurosystem staff projection from June 6, 2013 for comparison. While it would imply a longer period of low rates, it does not match past ECB decisions as well as the reaction function with SPF forecasts

A Comparison of Two Measures of Oral Reading Fluency

Reading fluency is an important part of the process of learning to read. It is commonly assessed by the use of Curriculum-Based Measurement (CBM) techniques; however, a new assessment method emerged in the Woodcock-Johnson Tests of Achievement- Third Edition (WJ-III). Only one previous study had examined the validity of the Reading Fluency test from the WJ-III by comparing it to established CBM measures of reading fluency for a sample of third-grade students. The resulting correlation between the two measures supported the validity of the WJIII Reading Fluency test, but it was unclear as to the two tests\u27 relationship across grade levels. To address this question, the current study examined the relationship between the Dynamic Indicators of Basic Early Literacy Skills test of Oral Reading Fluency (DORF) a standardized CBM-type measure, and the WJ-III Reading Fluency test with students from grades one, three, and five. Results supported the use of the WJ-III Reading Fluency test as a valid measure of reading fluency across grade levels

Computational morphogenesis of free form shells: Filter methods to create alternative solutions

p. 536-547Actual trends in numerical shape optimal design of structures deal with handling of very large dimensions of design space. The goal is to allowing as much design freedom as possible while considerably reducing the modelling effort. As a consequence, several technical problems have to be solved to get procedures which are robust, easy to use and which can handle many design parameters efficiently. The paper briefly discusses several of the most important aspects in this context and presents many illustrative examples which show typical applications for the design of light weight shell and membrane structures.Bletzinger, K.; Firi, M.; Linhard, J.; Wüchner, R. (2009). Computational morphogenesis of free form shells: Filter methods to create alternative solutions. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/654

Design of an Analysis Environment for Planning Decision Support

In this contribution, the design of an analysis environment is presented, that supports an analyst to come to a decision within a gradual collaborative planning process. An analyst represents a project manager, planner or any other person, involved in the planning process. Today, planning processes are managed by several geographically distributed planners and project managers. Thus, complexity of such a process rises even more. Prediction of consequences of many planning decisions is not possible, in particular since assessment of a planning advance is not trivial. There have to be considered several viewpoints, that depend on individual perceptions. In the following, methods are presented to realize planning decision support

Variation of Reference Strategy - A Novel Approach for Generating Optimized Cutting Patterns of Membrane Structures

AbstractFinding the plane shape of the double curved surfaces is a well-known challenge for every design engineer dealing with either fiber reinforced plastics lightweight designs or textile architectural membranes. A novel approach for generating optimized cutting patterns including nonlinear isotropic and anisotropic material behavior is presented. The so-called Variation of Reference Strategy can be seen as an inverse approach, defining the nodal positions in the material configuration as design variables holding the spatial configuration fixed. Thereby, the stress-free state of the cutting pattern which is an important characteristic of the manufacturing process is preserved. In order to demonstrate the abilities and robustness of the Variation of Reference Strategy several numerical examples considering different kind of materials are presented

A modified particle swarm optimizer and its application to spatial truss topological optimization

p. 1044-1057Particle Swarm Optimization (PSO) is a new paradigm of Swarm Intelligence which is inspired by concepts from 'Social Psychology' and 'Artificial Life'. Essentially, PSO proposes that the co-operation of individuals promotes the evolution of the swarm. In terms of optimization, the hope would be to enhance the swarm's ability to search on a global scale so as to determine the global optimum in a fitness landscape. It has been empirically shown to perform well with regard to many different kinds of optimization problems. PSO is particularly a preferable candidate to solve highly nonlinear, non-convex and even discontinuous problems. In this paper, one enhanced version of PSO: Modified Lbest based PSO (LPSO) is proposed and applied to one of the most challenging fields of optimization -- truss topological optimization. Through a benchmark test and a spatial structural example, LPSO exhibited competitive performance due to improved global searching ability.Yang, B.; Bletzinger, K. (2009). A modified particle swarm optimizer and its application to spatial truss topological optimization. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/676

Conception and design of membrane structures considering their non-linear behavior

The lack of unified verification approaches and standards like the Eurocodes for various materials is a limiting factor to further propagation of architectural membranes. This paper will discuss the possibilities and challenges of integrating the design and verification of membrane structures into the Eurocodes’ philosophy. Therefore an overview of existing guidelines will be given, followed by a discussion of the underlying principles of the Eurocodes. Especially the non-linear behavior of architectural membranes distinguishes them from other structures. Therefore the focus of this contribution is to discuss the implications of this non-linearity on verification approaches. Theoretical considerations as well as in-depth examples help to clarify the necessary basis. Finally the consequences of non-linearity on the verification of the primary structure and hybrid structures are presented

Advanced cutting pattern generation – Consideration of structural requirements in the optimization process

This paper presents extensions to optimized cutting pattern generation through inverse engineering regarding structural requirements. The optimized cutting pattern generation through inverse engineering is a general approach for the cutting pattern generation which is based on the description of the underlying mechanical problem. The three dimensional surface, which is defined through the form finding process, represents the final structure after manufacturing. For this surface the coordinates in three dimensional space Ω3D and the finally desired prestress state σprestress are known. The aim is to find a surface in a two dimensional space Ω2D which minimizes the difference between the elastic stresses σel,2D→3D arising through the manufacturing process and the final prestress σprestress. Thus the cutting pattern generation leads to an optimization problem, were the positions of the nodes in the two dimensional space Ω2D are the design variables. In this paper various improvements to the method will be shown. The influence of the seam lines to the stress distribution in the membrane is investigated. Additionally, the control of equal edge length for associated patterns is an example for important enhancement

The eXtended Updated Reference Strategy for the form finding of tensile structures

In this paper, the eXtended Updated Reference Strategy is presented. Starting from the established Updated Reference Strategy all related issues, which are involved for this methodology, are identified. It will be shown that the eXtended Updated Reference Strategy is able to solve the “correct” form finding problem in one non-linear iteration step. By applying the eXtended Updated Reference Strategy to well-known form finding problems the difference in convergence in comparison to establish methods like the force density method or the Updated Reference Strategy is discusse