Structural model

In this study we demonstrate an approach to replacing validated selection tests to which job applicants may have prior access. This approach, labeled construct equivalence, allows for replacing valid tests currently in use with new, experimental tests that have been shown to measure the same constructs. We demonstrated the construct equivalence approach by collecting data from over 2,000 applicants for four different positions in a large petrochemical company. We investigated the equivalence of the experimental and the current tests by using correlational analyses, structural modeling, and analyses of hiring decisions. Results indicated that the experimental and current tests measure the same constructs and that replacing the current tests with the experimental tests would treat ethnic and sex subgroups consistently. Construct equivalence was shown to be a viable approach to test substitution.

Abstract: This paper proves that non-convex quadratically constrained quadratic programs have an exact semidefinite relaxation when their underlying graph is acyclic, provided the constraint set satisfies a certain technical condition. When the condition is not satisfied, we propose a heuristic to obtain a feasible point starting from a solution of the relaxed problem. These methods are then demonstrated to provide exact solutions to a richer class of optimal power flow problems than previously solved.

Objectives: Time-kill studies are commonly used in investigations of new antimicrobial agents. However, they typically provide descriptive information on pharmacodynamics. We developed a mathe- matical model to capture the relationship between microbial burden and antimicrobial agent concentrations. Methods: Time-kill studies were performed with 108 cfu/mL of Pseudomonas aeruginosa at baseline. Meropenem at 0, 0.25, 1, 4, 16 and 64 3

... Firm investment in imperfect capital markets: A structural estimation. Sangeeta Pratap Corresponding Author Contact Information , E-mail The Corresponding Author , a and Sílvio Rendon E-mail The Corresponding Author , b. ... Agency costs, net worth, and business fluctuations. ...

SUMMARY: A shallow subsurface-structure model improves the accuracy and applicable frequency-range of broadband ground-motion prediction. We have integrated a 3D velocity model of the shallow subsurface structure beneath the Tokyo metropolitan area by compiling about 78,500 borehole data. The model provides the depth of Vs = 500 m/s which is compatible with the upper surface of the Shimosa layer, and

We discuss the admissible parameter space for some state space models, including the models that underly exponential smoothing methods. We find that the usual parameter restrictions (requiring all smoothing parameters to lie between 0 and 1) do not always lead to stable models. We also find that all seasonal exponential smoothing methods are unstable as the underlying state space models are neither reachable nor observable. This instability does not affect the forecasts, but does corrupt the state estimates. The problem can be overcome with a simple normalizing procedure. Finally we show that the admissible parameter space of a seasonal exponential smoothing model is much larger than that for a basic structural model, leading to better forecasts from the exponential smoothing model when there is a rapidly changing seasonal pattern.

By internal oxidation of AgMg- and PdMg-alloys small precipitates ofMgO are formed within the Ag- or Pd-matrix. Thetotal area of the metal/oxide interface produced this way becomes severalsquare meters in one cubic centimeter of metal. Segregation of oxygen at theinterface is determined by desorption of gaseous oxygen for theAg/MgO-interface and by trapping of hydrogen for the Pd/MgO-interface. At673 to 873

Innovation in SMEs exhibits some peculiar features that most traditional indicators of innovation activity do not capture. Therefore, in this paper, we develop a structural model of innovation that incorporates information on innovation success from firm surveys along with the usual R&D expenditures and productivity measures. We then apply the model to data on Italian SMEs from the “Survey on Manufacturing Firms” conducted by Mediocredito-Capitalia covering the period 1995–2003. The model is estimated in steps, following the logic of firms’ decisions and outcomes. We find that international competition fosters R&D intensity, especially for high-tech firms. Firm size and R&D intensity, along with investment in equipment, enhances the likelihood of having both process and product innovation. Both these kinds of innovation have a positive impact on firm’s productivity, especially process innovation. Among SMEs, larger and older firms seem to be less productive.

Plants with specific resistance to a single class of herbicides have been genetically engineered by introduction of genes encoding rationally designed mutant acetohydroxyacid synthase (AHAS) enzymes. Suitable substitution mutations were identified from a three-dimensional model of an AHAS-inhibitor complex. The structural model was generated based on homology to pyruvate oxidase and an imidazolinone inhibitor was positioned in the proposed binding site using structure-activity data for this class of herbicide. Biochemical analysis of the mutant proteins expressed in Escherichia coli enabled iterative optimization of the mutant genes. Expression of recombinant proteins in tobacco plants conferred resistance in vivo. The novel approach coupling molecular modeling and molecular biology has many advantages over traditional random mutagenesis and selection methods and will be crucial to the future development for environmentally safe and sustainable agricultural systems.

Purpose – The purpose of the study is to examine the influence of multiple factors on the green purchase intention of customers in Australia. Design/methodology/approach – A conceptual model is proposed and was subjected to empirical verification with the use of a survey of metropolitan and regional households in Victoria, Australia. The data were analyzed using both descriptive measures and

This paper explores long-term partnership benefits of local strategic alliances in knowledge-intensive industries. A structural model of the value continuum is formulated and tested on small and mid-size enterprises in the software industry. Partial least squares path analysis is used to investigate the cause–effect relationships between the foundation values – efficiency and effectiveness – and the innovation value. The results show that the innovation value of localised inter-firm networks originates from costs savings and quality improvements. Conversely, alliance-induced 'speed' benefits (measured by the R&D process's acceleration), which improve flexibility and/or shorten delivery time, have no significant impact on market-based performance. An alliance's time-related benefits may be important to maintain competitive parity, but they do not significantly support competitive advantage, market development and market penetration. Instead, value is created via, for example, an exchange of tacit knowledge and a reduction in transaction costs, and particularly by a reduction in customer service costs.

... the exclusive use of linear aerodynamic theories for predicting the unsteady aerodynamic forces. ... Because of this computational cost, the potential of CFD-based nonlinear aeroelastic codes ... possible however to address this limitation with the use of reduced-order models (ROMs ...