Multivariate statistical analysis of a high rate biofilm process treating kraft mill bleach plant effluent.

This study reports on a multivariate analysis of the moving bed biofilm reactor (MBBR) wastewater treatment system at a Canadian pulp mill. The modelling approach involved a data overview by principal component analysis (PCA) followed by partial least squares (PLS) modelling with the objective of explaining and predicting changes in the BOD output of the reactor. Over two years of data with 87 process measurements were used to build the models. Variables were collected from the MBBR control scheme as well as upstream in the bleach plant and in digestion. To account for process dynamics, a variable lagging approach was used for variables with significant temporal correlations. It was found that wood type pulped at the mill was a significant variable governing reactor performance. Other important variables included flow parameters, faults in the temperature or pH control of the reactor, and some potential indirect indicators of biomass activity (residual nitrogen and pH out). The most predictive model was found to have an RMSEP value of 606 kgBOD/d, representing a 14.5% average error. This was a good fit, given the measurement error of the BOD test. Overall, the statistical approach was effective in describing and predicting MBBR treatment performance.     

Protection versus Promotion: An Empirical Investigation

Using Turkish industry-level data from 1983 to 1990, we find that politically organized industries receive both higher protection and promotion than unorganized ones. Tariff rates are decreasing (increasing) in the import-penetration ratio and the absolute value of the import-demandelasticity for organized (unorganized) industries. Subsidy rates are decreasing (increasing) in the output-supply elasticity for organized (unorganized) industries. The results are consistent with the predictions of the Grossman–Helpman model and its extension in this paper. The mix of protection and promotion is inversely related to the ratio of their respective marginal deadweight cost measures.     

The Falsification of Four Popular Hypotheses About the Asian Crisis

Various claims have been made about the causes of the Asian crisis and its spread. Here, we use data on the behaviour of capital flows during the crisis to test the strong forms of four such hypotheses, that portfolio investors and hedge funds played a dominant role in initiating and/or spreading the crisis; that moral hazard kept efficient markets from predicting the crisis; and, finally, the common lender hypothesis of Kaminsky and Reinhart. In the process we also test implications of the Calvo-Mendoza model of rational investor ignorance. All are falsified as monocausal explanations. For example, portfolio investments that could not have been subject to substantial moral hazard continued to flow into Asia until very shortly before the crisis. Likewise, banks were a much larger source of capital outflows during the crisis than were portfolio investors. While falsified in their strongest forms, several of these hypotheses in less strong forms should play a role in a more nuanced analysis. It is necessary to move past simple single-factor approaches in order to produce a more complete, synthetic explanation of this episode.     

STRATEGIC ORIENTATION,CAPABILITIES, AND PERFORMANCE IN MANUFACTURER — 3PL RELATIONSHIPS

This study examines how two dimensions of strategic orientation (customer and competitor orientation) influence logistics and market performance. Two capabilities, operational flexibility and collaboration, are studied. Data were collected from manufacturers working with third party logistics providers. The findings suggest that customer and competitor orientations have different influences upon performance when leveraged through the capabilities. Competitor orientation, while having a detrimental direct effect on logistics performance, appears to be the better strategic approach, when supported with operational flexibility since it results in enhanced logistics (efficiency) and market (effectiveness) performance. Customer orientation, on the other hand, greatly improves logistics performance, i.e., internal efficiency.     

Simultaneous visualisation of biofouling, organic and inorganic particle fouling on separation membranes.

Fouling is a major problem in membrane processes of water treatment. It can be caused by the deposition of inorganic and organic particulate material, and of microbial cells which may subsequently form biofilms. In practice, usually more than one foulant participates in the formation of membrane deposits. Knowledge of the composition of fouling layers is important for the development of appropriate countermeasures. For this purpose, an experimental system was established for the generation and microscopic visualisation of mixed deposits, using fluorescently labelled model foulants: (i) drinking-water bacteria stained with nucleic acid-specific dyes (biofouling), (ii) synthetic clay mineral laponite stained with rhodamine 6G (inorganic particle fouling), and (iii) fluorescently labelled polystyrene microspheres (organic particle fouling). Polycarbonate and polyethersulfone membranes were challenged with these foulants by dead-end filtration. On the basis of different fluorescent labels, the single foulants in these mixed deposits could be visualised separately by confocal laser scanning microscopy which, in combination with image analysis, allowed the generation of three-dimensional views of the complete deposits. This method offers the possibility for the estimation of quantitative surface coverage by foulants and for the determination of the efficacy of cleaning measures with respect to the removal of different foulants.     

HEDGING INTEREST RATE RISK UNDER TERM STRUCTURE EFFECTS: AN APPLICATION TO FINANCIAL INSTITUTIONS

In this paper we investigate the use of the structured full rank model for hedging the balance sheet of a financial institution. Simulation results suggest that the optimal hedge is insensitive to changes in parameter estimates. In addition, we hedge a portfolio of Treasury bills using both the full information covariance matrix and the structured covariance matrix. We then contrast these results with those obtained from a duration-based model. Empirical results suggest that the structured full rank model is generally more effective in hedging applications than either the full information model or duration-based model.     

From Experience: Avoiding Marketing's Best-Of-The-Best Specification Trap

Too often companies fall into a trap when developing a list of performance specifications for a new product. Milton Rosenau calls this the best-of-the-best specification trap. The problem arises whenever a company bases a specification on the combination of the best single features observed in available competitive products. When this happens, the new product's design is driven by competition and is not derived from a unique market insight. This may not provide the basis for a sustainable advantage. Sometimes, rumors of competitive improvements may even lead to sudden changes in the specification, creating delays in the development process. A far better goal is to develop a specification that responds to an unrecognized and unfilled user need, one that adds high value to users. His points are illustrated with several examples.