Error Cost Escalation Through the Project Life Cycle

It is well known that the costs to fix errors increase as the project matures, but how fast do those costs build? A study was performed to determine the relative cost of fixing errors discovered during various phases of a project life cycle. This study used three approaches to determine the relative costs: the bottom-up cost method, the total cost breakdown method, and the top-down hypothetical project method. The approaches and results described in this paper presume development of a hardware/software system having project characteristics similar to those used in the development of a large, complex spacecraft, a military aircraft, or a small communications satellite. The results show the degree to which costs escalate, as errors are discovered and fixed at later and later phases in the project life cycle. If the cost of fixing a requirements error discovered during the requirements phase is defined to be 1 unit, the cost to fix that error if found during the design phase increases to 3 - 8 units; at the manufacturing/build phase, the cost to fix the error is 7 - 16 units; at the integration and test phase, the cost to fix the error becomes 21 - 78 units; and at the operations phase, the cost to fix the requirements error ranged from 29 units to more than 1500 unit

The realities of storing carbon dioxide - A response to CO2 storage capacity issues raised by Ehlig-Economides & Economides

In a recent publication, Ehlig-Economides & Economides (2010) have sought to demonstrate that carbon dioxide capture and storage (CCS) is not technically or economically feasible, based on a supposed lack of underground storage capacity. We consider this to be a serious misrepresentation of the scientific, engineering and operational facts surrounding CCS. Ehlig-Economides & Economides raise a number of storage related issues: reservoir boundaries, capacity, pressure management, storage integrity, dissolution and storage in depleted reservoirs. We take each one in turn, highlighting specific errors in the paper but also drawing attention to more general background issues. Finally, we discuss in more detail some inconsistencies in the paper surrounding the reservoir engineering calculations

Global Optimization Studies on the 1-D Phase Problem

this paper (and partially reported earlier in [Lovell & Zwick, 1992]) was approximately ten years ago -- as is revealed later in the citation of both hardware and software used, but it remains relevant today: a general solution of the phase problem is not significantly nearer now than it was then, and the RPP is not yet in use as a simple test system either for phase problem explorations or global optimization studies. This investigation was originally motivated by a desire to find new approaches to the phase problem. Although the results obtained did not suggest that the phase problem would be solvable by these means, still, as applications of the Genetic Algorithm and of Simulated Annealing, the efforts reported here are rather preliminary. Better results may be achievable by more sophisticated GA and SA techniques. At the very least, the phase problem provides a problem context in which the properties of the Genetic Algorithm and Simulated Annealing can be explored. Global Optimization Studies on the 1-d Phase Problem 4 2. THE GENETIC ALGORITHM 2.1 Basic

Socio-ec(h)o: Ambient intelligence and gameplay

This paper describes the preliminary research of an ambient intelligent system known as socioec(h)o. socio-ec(h)o explores the design and implementation of an ambient intelligent system for sensing and display, user modeling, and interaction models based on game structures. Our interaction model is based on a game structure including levels, body states, goals and game skills. Body states are the body movements and positions that players must discover in order to complete a level and in turn represent a learned game skill. The paper provides an overview of background concepts and related research. We describe the game structure and prototype of our environment. We discuss games research concepts we utilized and our approach to group user models based on Richard Bartle’s game types. We explain the role of embodied cognition within our design and elaborate on what we chose to encode as embodied actions, cognition and communication. We describe how we utilized selective responses that were real-time, gradient, provided rewards and were unique to different group user models. We introduce our approach to designing ambient intelligent systems that is ecologically inspired. We stress the empirical nature of the design work and the role of participatory design in developing our system

The AuScope Project and Trans-Tasman VLBI

Three 12-meter radio telescopes are being built in Australia (the AuScope project) and one in New Zealand. These facilities will be fully-equipped for undertaking S and X-band geodetic VLBI observations and correlation will take place on a software correlator (part of the AuScope project). All sites are equipped with permanent GPS receivers to provide co-location of several space geodetic techniques. The following scientific tasks of geodesy and astrometry are considered. 1. Improvement and densification of the International Celestial Reference Frame in the southern hemisphere; 2. Improvement of the International Terrestrial Reference Frame in the region; 3. Measurement of intraplate deformation of the Australian tectonic plate