Day-night differences in Cunene horse mackerel (Trachurus trecae) acoustic relative densities off Angola

The assessment and the management of the Cunene horse mackerel in Angola rely heavily on abundance estimates from hydroacoustic surveys. Acoustic data collected from 1994 to 1999 were analysed to quantify diurnal variation in relative acoustic densities at 38 kHz. The nautical-area scattering coefficient (s(A), m(2) nautical mile(-2)) was characterized by clear day night differences: s(A) values recorded during the day were significantly higher (mean s(A): 135 m(2) nautical mile(-2)) than the corresponding night-time values (mean s(A) 83 m(2) nautical mile(-2)). This pattern is associated with differences in behaviour and horizontal and vertical distributions between day and night: by day, the fish school near the seabed, and by night, they move into the pelagic zone and disperse into widespread scattering layers. More than 40% of the total backscatter by day originated from the bottom 10 m, but at night this proportion decreased to <10%. The findings demonstrate considerable influences of behaviour and aggregation dynamics on acoustic measurements. Possible implications for the estimates of acoustic abundance are discussed in the light of the differences.Norwegian Agency for Development Cooperation (NORAD); Dr Fridtjof Nansen programme; Gulbenkian Foundationinfo:eu-repo/semantics/publishedVersio

Road expansion and market integration in the Austrian low countries during the second half of the 18th century.

We analyse the integration of wheat markets across 18 towns in the Austrian Low Countries during the second half of the 18th century and the relationship with the rapidly expanding paved road network in this period. We use a switching regression approach (threshold cointegration) to study long-run and short-run integration of these markets, using monthly wheat prices. We find that throughout this period, markets were spatially interconnected. However, price margins adjust only slowly to long-term levels in response to local shocks. We also find that transaction costs are relatively high. The results suggest a complex market with regular trade flow reversals and periods of unprofitable trade between key markets. It is widely accepted in Belgian historiography that the construction of a paved road network caused a substantial reduction in transaction costs. Our research, however, indicates that distance, fixed costs or links by rivers and canals mainly influenced transaction costs, not the expansion of a paved road network. Two factors can account for this. First, the toll structure on paved roads discouraged bulk trade. Secondly, new private investment in inter-city grain trade that may have led to cuts in the trading costs, typically appeared to be absent in this period. However, adjustment speeds in markets are significantly affected by the existence of paved roads. Better communication and faster transport due to the road network resulted in faster arbitrage.

The Effectiveness of Hooks for Plain Steel Reinforcement

As buildings age, their structural integrity must be assessed and reassessed at regular intervals to ensure the safety of their continued use and to advise on retrofits and repairs necessary for preventative maintenance and responsive repair. Historic buildings often contain plain reinforcement whereas modern buildings exclusively contain modern deformed reinforcement. Younger engineers in particular have not been trained with or worked with plain bar. Modern American Concrete Institute (ACI) and Canadian Standards Association (CSA) Group codes largely do not contain adequate provisions to assess the structural integrity of many historic buildings. Twenty-four beam-column joint specimens with four different hook configurations were tested under tension to compare the anchorage capacities of embedded plain and modern deformed 90° and 180° hooked bars. Six replicates of each configuration were tested to determine whether statistically significant differences at the 95% confidence level existed between the anchorage capacities of plain versus modern deformed hooked bars. Visual observations were documented manually to assess differences between crack patterns and observed failure modes. Typical cracking patterns were observed for groups of both specimens containing 90° and 180° hooks. The degree of cracking observed aligned with results of similar studies. All specimens with 90° hooks failed by side blowout whereas those with 180° hooks failed by front blowout. No evidence of group effects (i.e. decreased anchorage capacity) was observed. Statistically significant differences in maximum normalized tensile load at the 95% confidence level were observed between 90° plain and modern deformed bars, wherein the plain bars had a 3.8 kN/MPa lower maximum; 180° plain and modern deformed bars, wherein the plain bars had a 5.6 kN/MPa lower maximum; and 90° and 180° modern deformed hooked bars, wherein the 90° bars had a 4.0 kN/MPa lower maximum. No statistically significant differences in displacement at maximum normalized load were observed. An extensive replicate-based study of plain hooked bar incorporating additional parameters (e.g. lead length, bend angle, etc.) is recommended. The value of the recommended work is in determining the sensitivity of hooked bar performance to variations in these parameters

Organisational Implementation of Collaboration Technologies - an integrative review

The paper presents an integrative review of field-based research on organisational implementation of collaboration technologies. Based on a typology of collaboration technologies, findings from previous implementation research related to different types of technologies are identified and discussed. A taxonomy of implementation factors is presented, that may serve as the basis for further implementation research and development of implementation strategies for different types of collaboration technology

Using IT for Strategic Competence Management: Potential Benefits and Challenges

The recent development in IT-based HRM systems implies increased potential for using these systems to support the strategic competence management process in organizations. The paper discusses potential benefits and challenges related to implementation of IT-based competence systems, based on a case study of the implementation of a global competence management system in the telecommunications company Ericsson. In addition to providing overview of the competence resources in the organization and identifying competence areas in need of further development, the system also supports Ericsson’s knowledge networking strategy, through locating experts and stimulating emerging ’communities of knowing’. Several challenges were identified, related to designing a suitable competence framework, tensions between global standardization and local practices, and in gaining commitment among the employees

Four Integration Patterns: IS Development as Stepwise Adaptation of Technology and Organziation

Integration and adaptation between an information system and the related business organisation is an important challenge for IS development project managers. Both IS research and software engineering research have contributed important lessons on integration, but at the practical level of IS development projects the processes of integration and mutual adaptation is less well understood. In this paper we apply a socio-technical perspective to analyze the integration of stakeholders and technical components, and we identify four generic integration patterns; Big Bang, Stakeholder Integration, Technical Integration and Socio-Technical Integration. Three case studies of iterative software development projects are used to illustrate the patterns. These illustrations highlight the management challenges of iterative integration. While early integration increases the likelihood of implementation success, it also increases the complexity of the projects. For practitioners the four integration patterns represent an analytical tool for planning iterative systems development projects. For IS research the four integration patterns are a contribution to a vocabulary for describing socio-technical integration

Counteracting Forces in Implementation of IS-Enabled Global Business Processes

Many companies consider and undertake outsourcing of their software-development activities. Often information systems development is outsourced to vendors in different cultures or with a different level of software-process maturity. Recommendations for managing such outsourcing arrangements typically involve that client and vendor should increase interaction, learn more about the culture of the other part, communicate more, form partnerships, and the like. We have studied a client that did the opposite with a successful outcome. Based on a case study we lay out the story of how interaction between client and vendor on purpose was minimized. What mechanisms were used? What worked and what did not? We conclude that minimizing interaction can be a viable strategy to follow when clients face large cultural and maturity inequality in offshoring their software-development activities

An approach to produce a stack of photo definable polyimide based flat UTCPs

Getting output of multiple chips within the volume of a single chip is the driving force behind development of this novel 3D integration technology which has a broad range of industrial and medical electronic applications. This can be achieved by laminating multiple layers of spin-on polyimide based ultrathin chip packages (UTCPs) with fine pitch through hole interconnects