Coupling GIS with Hydrologic and Hydraulic Flood Modelling

Geographic Information Systems (GIS) have been recognised as a powerful means to integrate and analyse data from various sources in the context of comprehensive floodplain management. As part of this comprehensive approach to floodplain management, it is very important to be able to predict the consequences of different scenarios in terms of flooded areas and associated risk. Hydrologic and hydraulic modelling plays a crucial role and there is much to gain in incorporating these modelling capabilities in GIS. This is still a rather complex task and research is being done on the full integration of these models. Interfacing between these models and GIS may be a very efficient way of overcoming the difficulties and getting very good results in terms of engineering practice. This paper presents results based on the use of Intergraph GIS coupled with Idrisi GIS. Using these two systems substantially increased the flexibility of using GIS as a tool for flood studies. A lumped (XSRAIN) and a distributed (OMEGA) hydrologic models were used to simulate flood hydrographs. The well known HEC-2 Hydraulic model was used to compute flooded areas. These models were applied in the Livramento catchment with very good results. The computation of flooded areas for different flood scenarios, and its representation in GIS, can be used in the assessment of affected property and associated damages. This is a very useful GIS-based approach to floodplain management.     

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.     

Energy Production in Water Distribution Networks: A PAT Design Strategy

Pump operating as turbine (PAT) is an effective source of reducing the equipment cost in small hydropower plants. However, the manufacturers provide poor information on the PAT performance thus representing a limit for its wider diffusion. Additional implementation difficulties arise under variable operating conditions, characteristic of water distribution networks (WDNs). WDNs allow to obtain widespread and globally significant amount of produced energy by exploiting the head drop due to the network pressure control strategy for leak reductions. Thus a design procedure is proposed that couples a parallel hydraulic circuit with an overall plant efficiency criteria for the market pump selection within a WDN. The proposed design method allows to identify the performance curves of the PAT that maximizes the produced energy for an assigned flow and pressure-head distribution pattern. Finally, computational fluid dynamics (CFD) is shown as a suitable alternative for performance curve assessment covering the limited number of experimental data.     

Anaerobic monodigestion of poultry manure: determination of operational parameters for CSTR

In this work the anaerobic monodigestion for the treatment of turkey manure was evaluated, without its codigestion with another substrate. The effect of the organic loading rate (OLR) and the substrate concentration (high total solids (TS) concentration) or product concentration (high volatile fatty acids (VFA) and/or ammonia (NH(3)-N) concentrations) was studied. The results show that for a continuous stirred tank reactor (CSTR) operation, a maximum of 40 g/L of TS and 4.0 g/L of ammonium (NH(4)(+)) was required. In addition, the maximum organic loading rate (OLR) will not exceed 1.5 kg VS/m(3)d. Higher TS and NH(4)(+) concentrations and OLR lead to a reduction on the methane productivity and volatile solids (VS) removal. During the CSTR operation, a high alkalinity concentration (above 10 g/L CaCO(3)) was found; this situation allowed maintaining a constant and appropriate pH (close to 7.8), despite the VFA accumulation. In this sense, the alkalinity ratio (α) is a more appropriate control and monitoring parameter of the reactor operation compared to pH. Additionally, with this parameter a VS removal of 80% with a methane productivity of 0.50 m(3)(CH4)/m(3)(R)d is achieved.     

Analysing job creation effects of scaling up infrastructure spending in South Africa

In a first for South Africa, this article draws on literature on infrastructure productivity to model dynamic economy-wide employment impacts of infrastructure investment funded with different fiscal tools. Using a dynamic computable general equilibrium model, the South African investment plan is modelled, given the infrastructure externality. Alternative fiscal scenarios to finance the policy are modelled in the article. In the long run, unemployment decreases for all types of workers under one of the scenarios. In the short run, only elementary occupation workers benefit from a decrease in unemployment; for the rest, unemployment rises.     

Learning CAD at university through summaries of the rules of design intent

The ease with which 3D CAD models may be modified and reused are two key aspects that improve the design-intent variable and that can significantly shorten the development timelines of a product. A set of rules are gathered from various authors that take different 3D modelling strategies into account. These rules are then applied to CAD strategic-knowledge learning methodology and included in 3D CAD modelling exercises for students following the degree in mechanical engineering at the University of Burgos (Spain). The experiment was conducted in two groups with a total of 75 students. The design-intent rules were introduced in the different exercises that the teacher explained in both the theoretical and the practical classes. In addition, a summary of the different design rules in each of the practical exercises was explained in the practical classes in only one of the groups. The experimental results, reported in this paper, tested the influence of these summaries on overall improvements in 3D modelling and on the design-intent variable, which is subdivided into four sections: skeleton, structures, alterations and constraints. The use of the summaries of the design intent rules led to statistically significant improvements in 3D modelling in the experimental group, in comparison with the group of students to whom those summaries were not explained.     

Detection of Leakage Freshwater and Friction Factor Calibration in Drinking Networks Using Central Force Optimization

Inverse Transient Analysis (ITA) is a powerful approach for leak detection and calibration of friction factors in pressurized pipes. Through this method, a transient flow is initiated and pressures are measured somewhere in the system. Then, a nonlinear programming (NLP) problem with a least-squares criterion objective function is developed to minimize discrepancies between the measured and calculated pressures at measurement sites. Solving the raised NLP results in the problem’s unknowns being leakage specifications and pipe friction factors. For this purpose, various optimization techniques may be utilized. This issue is a major challenge for ITA-based methods. The present work aims at applying the new method of Central Force Optimization (CFO) to the problem of ITA. CFO is a deterministic metaheuristic inspired by gravitational kinematics in which small objects in space are dragged by bigger ones. Herein, the concept and main structure of CFO are represented as well as of CFO. A reference pipe-network is considered to be solved using the ITA equipped with CFO. The results are then discussed compared to the previous works. It is concluded that CFO is easy to implement, computationally efficient and has a remarkable performance in solving leak detection problem.     

The impact of network configurations on value constellations in business markets — The case of an innovation network

A growing body of scholars are advocating a better understanding of how value is created in business networks, rather than merely in business relationships or at the level of single actors. Among such networks, innovation networks, i.e. the configurations of strategic entrepreneurial nets aimed at improving the effectiveness of innovation performance, have come under scrutiny in the business marketing literature. However, research that explicitly connects value considerations with innovation network configurations is still in its infancy, with empirical evidence being notably scarce. This study is aimed at identifying if and how network configurations affect value constellation aspects in business networks, in terms of value recipients and value outcomes. We interviewed key informants representing 46 high-technology entrepreneurial firms co-located in an innovation network (Daresbury Science and Technology Park — UK). Our study identifies that different network configurations can co-exist in the same overall network; these, nevertheless, are not alternative independent structures, but rather they interact with each other through actors spanning their boundaries. Our study thus provides an understanding of network configurations relating to specific value consequences, but also provides evidence relating to the interactions between different configurations. By doing this, we establish a bridge between a business marketing and a strategy perspective on value in networks. Important managerial implications and implications for policy makers also emerge from our study.     

The relationship of perception of time and attributes of leisure in daily experiences

The purpose of this study was to explore the relationship between perceived passage of time (slowly versus quickly) and perceived freedom, enjoyment, interest and subjective meaning of leisure in daily experiences of married couples. Eleven college-age married couples participated in this study. Data were collected using experience sampling method that produced a total of 650 self-reports. Couples were signalled at random five times a day for one week. Using logistic regression results suggest that some leisure attributes are more relevant in influencing perception of passage of time in husbands' and wives' daily experiences.     

A Sufficient Condition for Generalized Lorenz Order

In this paper, a sufficient condition for non-negative random variables to be ordered in the Generalized Lorenz sense is presented. This condition does not involve inverse distribution functions. Applications of this result to several income distribution models are given. Journal of Economic Literature Classification Numbers: D36, D69.