Software product roadmapping in a volatile business environment

Product roadmapping enhances the product development process by enabling early information and long-term decision making about the products in order to deliver the right products to the right markets at the right time. However, relatively little scientific knowledge is available on the application and usefulness of product roadmapping in software product development context. This study develops a framework for software product roadmapping, which is then used to study the critical aspects of the product roadmapping process. The collection of empirical evidence includes both quantitative and qualitative data which sheds further insight into the complexities involved in product roadmapping. Results revealed that organizations view the product roadmap mainly as a tool for strategic decision making as it aims at showing the future directions of the company's products. However, only a few companies appear to have an explicit approach for handling the mechanisms for creating and maintaining such a roadmap. Finally, it is suggested that the strategic importance of product roadmapping is likely to increase in the future and, as a conclusion, a new type of agility is required in order to survive in the turbulent and competitive software business environment.     

Multi-criteria evaluation of residential energy supply systems

In this paper, we consider the selection of a residential energy supply system as a multi-criteria decision-making problem, which involves both financial and environmental issues. Specifically, we compare micro-CHP (micro-cogeneration) heating with traditional heating systems through an evaluation that accounts for: (i) the decision-makers’ subjective preferences, (ii) uncertainties in the performance of micro-CHP heating systems (which are partly caused by the lack of long-term operational experiences) and (iii) the context-dependency of life-cycle costs and environmental burdens of heating systems. Motivated by these considerations, we employ the PAIRS multi-criteria decision-making methodology that captures incomplete information by way of interval-valued parameters and provides support for sensitivity analyses, too. Our comparative analysis of alternative heating systems suggests that micro-CHP is a reasonable alternative to traditional systems, particularly from the environmental point of view.     

Occurrence of nitrifiers and diversity of ammonia-oxidizing bacteria in developing drinking water biofilms

We studied the population dynamics of nitrifying bacteria during the development of biofilms up to 233 or 280 days on polyvinylchloride pipes connected to two full-scale drinking water distribution networks supplying processed and chloraminated surface water. The numbers of nitrifiers in biofilms were enumerated at intervals of 10–64 days by the most probable number (MPN) method at waterworks and at several study sites in distribution network areas. The numbers of nitrifiers increased towards the distal sites. The highest detected MPN counts of ammonia-oxidizing bacteria (AOB) for study areas 1 and 7 were 500 MPN cm⁻² and 1.0×10⁶ MPN cm⁻², and those of nitrite-oxidizing bacteria (NOB) 96 MPN cm⁻² and 2.2×10³ MPN cm⁻², respectively. The diversity of AOB was determined by PCR amplifying, cloning and sequencing the partial ammonia monooxygenase (amoA) gene of selected biofilm samples presenting different biofilm ages. The PCR primers used, A189 and A682, also amplified a fragment of particulate methane monooxygenase (pmoA) gene of methane-oxidizing bacteria. The majority of biofilm clones (24 out of 30 studied) contained Nitrosomonas amoA-like sequences. There were only two pmoA-like sequences of Type I methanotrophs, and four sequences positioned in amoA/pmoA sequence groups of uncultured bacteria. From both study area very similar or even completely identical Nitrosomonas amoA-like sequences were obtained despite of high difference in AOB numbers. The results show that the conditions in newly formed biofilms in drinking water distribution systems favor the growth of Nitrosomonas-type AOB.     

Removal of iron-containing impurities using the magnetic separation method

The methods of removal of iron-containing impurities from raw material are considered. In order to increase the efficiency of iron removal, dry refining of the raw material with self-cleaning roller-type separators with a magnetic system consisting of Nd - Fe - B permanent magnets is proposed. The installation of such separators will make it possible to remove from 50 to 90% of the iron-containing impurities present in the material. Translated from Steklo i Keramika, No. 1, pp. 28 – 29, January, 1999.     

Multicriteria Partner Selection in Virtual Organizations With Transportation Costs and Other Network Interdependencies

In this correspondence, we study how the selection of partners in a virtual organization (VO) can be assisted through mixed-integer linear programming (MILP) models. Additionally to fixed and variable costs, we present extensions that accommodate transportation costs, capacity risk measures, and interorganizational dependencies such as the success of past collaboration. Experiences from a real case study indicate that these models are helpful in VO decision making; computational experiments suggest that the models are tractable. In general, the MILP models are potentially applicable to a variety of portfolio selection problems.     

Adsorption of atomic and molecular oxygen on Cu(1 0 0)

We have studied the initial stages of the oxidation of the Cu(1 0 0) surface using ab initio calculations. Both atomic and molecular oxygen are addressed. We show that subsurface oxygen is not energetically favourable, but gets stabilized by on-surface O. We discuss the adsorption of molecular oxygen using elbow plots, which can be used in order to qualitatively understand the measured sticking coefficient at different oxygen coverages.     

Degradation of unglazed rough graphite-aluminium solar absorber surfaces in simulated acid and neutral rain

Degradation mechanisms of unglazed solar absorber surfaces based on aluminium substrate were studied. Rough graphite-aluminium surfaces were total-immersion subjected to aerated and de-aerated simulated neutral and acid rain. Test conditions were based on calculated absorber stagnation temperature and global rain acidity measurements. Changes in optical properties, elemental composition and sample mass were examined by spectrometry, energy dispersive X-ray spectrometry and thermogravimetry, respectively. The absorbers exhibited almost no degradation at pH value of 3.5. At pH 5.5 alumina on the surface hydrated significantly degrading the optical properties of the surfaces severely in most cases. Therefore these absorber surfaces can not be recommended to be used in non-glazed applications if they are exposed to rain with pH exceeding 3.5–4.5. The total-immersion test needs to be developed further as the test results exhibited poor temperature and time dependency thus preventing accurate service lifetime estimates. Still, these tests were useful in determining favourable and non-favourable operating conditions for the absorber surfaces based on aluminium substrate.     

Effects of speed limit variation on judged mean speed of a trip

Three experiments were set up to study how drivers estimate mean travel speeds on trips with different speed limits. To specify, participants judged mean speeds of trips with speed limits on different distances of the trip. Study 1 showed that the mean speed on a road with a temporary 30 km/h speed limit was overestimated if the speeds were greater than 80 km/h on the rest of the trip. Study 2 replicated and extended the results to problems with more speed combinations. In Study 3 the distances of the speed limits were varied and the results showed that a temporary 30 km/h speed restriction gave overestimations of the mean speeds of a trip for all combinations of original and temporary speed limits over all distances. Finally, some psychological issues and applied implications for speed regulation policies were discussed.