Sustainability of bridge maintenance

Bridge maintenance activities are important to consider within sustainable development due to the cost and environmental impact associated with various maintenance activities. Comparisons have been made between different bridge structural forms, based on materials, components and construction method, but less information is available on bridge maintenance activities to help decide a sustainable structural form. Typical maintenance aspects of the predominant forms of bridge structure (i.e. concrete, steel and masonry bridges) were considered in this study to reveal their sustainability in terms of materials, energy, transportation, human health and ecosystems. The results indicate that concrete and steel bridge maintenance activities have an average impact of 42% and 46% compared with 12% for masonry bridge maintenance activities. It is concluded that the component parts of concrete and steel bridges should be revised as they play an integral role in the selection of maintenance options

Visual Databases as Documentation and On-Line Information Systems

After the wide-spread use of computers as task processors, either for algorithmic operations, or for advanced interfaces, the emphasis has shifted on computers as communicators. Beyond basic serial communications, computers serve as providers of information, linking organizations and expanding the bounded rational of professionals. Based on the use of computers as communica-tors, a multiplicity of visual databases for architecture have emerged in the recent years. Building on a maturing technology, those databases address different domains of design, either aiming to provide the designers with information for making informed decisions, or aiming to document prior designs. However, a common characteristic of those visual databases is a separation between the design of the database, versus the entering of the critical amount of data that can make the databases useful. While the research has progressed in the designs, and technological problems of data presentation and data transfer have reached workable solutions, most of the efforts have not succeeded yet in providing the critical mass of information that is required to make the use of the databases desirable. Furthermore, this effort seems as having less research interest, while the necessary amounts of data, and especially the updating of those data, makes the task impossible for academic institutions, and requires interorganizational efforts. This paper focuses on the duality of the databases, either as a form of documentation, or as on-line interactive information systems. Based on that distinction, it examines the required technology and the critical success factors of each type, and proposes that these databases add value to design and they have considerable market effects, which will drive their development and diffusion

Remote Teaching in Design Education - Educational and Organizational Issues and Experiences

The Department of Real Estate and Project Management (BMVB) of the Faculty of Architecture at the Delft University of Technology has been working closely with Professor Spiro N. Pollalis of Harvard University, Graduate School of Design in Cambridge, USA since 1991. His case-based interactive seminars about the management of the design & construction process have been highly appreciated by many generations of students. In Spring 2000, Pollalis suggested to extend the scope of his involvement by introducing a remote teaching component, the subject of his research in the last few years. As Information and Communication Technology (ICT) in the Design and Construction Industry is part of his lectures, it was appropriate to provide the students with a first hand experience on the subject. In the following experiment, the teacher would remain in his office at Harvard while the interactive work and discussion sessions with 130 students in a full lecture room would take place in Delft as planned. The consequences this experiment has had for the course, for the techniques and facilities used, how teachers and students experienced these, and which conclusions and recommendations can be made, are the topics of this paper

Knowledge, Agency, and Design Information Systems

This paper addresses CAAD from an organizational point of view. We employ recent developments in organizational economics to model the organizational processes in building design. Based on an analysis of (i) the cost of transferring knowledge, and (ii) agency cost in existing design organizations, we propose a framework for redesigning organizational processes and for developing appropriate design information systems. The paper describes work on a larger ongoing research project at the Harvard Design School on intra- and interorganizational design information systems

Five-year experience of cementless Oxford unicompartmental knee replacement

Purpose Cementless unicompartmental knee replacement (UKR) was introduced to address some of the problems that can occur following cemented UKR. The aim of this study was to report the 5-year experience of the first 512 medial cementless Oxford UKR implanted by two surgeons for the recommended indications. Methods The first consecutive 512 cementless Phase 3 Oxford UKRs implanted by two surgeons for the recommended indications between June 2004 and October 2013 were prospectively identified and followed up independently. All the procedures were carried out through a minimally invasive approach without eversion or dislocation of the patella. Patients were assessed clinically pre-operatively and at 1, 2, 5, 7 and 10 years after surgery with functional outcome scores and radiographs. Results There were eight reoperations of which six were revisions giving a 5-year survival of 98 % (95 % CI 94–100 %). At a mean follow-up of 3.4 years (1.0–10.2), the mean OKS was 43 (SD 7), AKSS (objective) was 81 (SD 13), and AKSS (functional) was 86 (SD 17). The first 120 cases had a minimum follow-up of 5 years (mean 5.9; range 5–10.2). In these patients, the mean OKS was 41 (SD 8), AKSS (objective) was 81 (SD 14), and AKSS (functional) was 82 (SD 18). There were no femoral radiolucencies and no complete tibial radiolucencies. 11 % of tibial components had partial radiolucent lines; the remaining 89 % had no radiolucencies. Conclusion The clinical results are as good as or better than those previously reported for cemented fixation. The radiographic results are better with secure bony attachment to the implants in every case. Level of evidence IV.</p

Five-year experience of cementless Oxford unicompartmental knee replacement

Purpose: Cementless unicompartmental knee replacement (UKR) was introduced to address some the problems that can occur following cemented UKR. The aim of this study was to report the five year experience of the first 512 medial cementless Oxford UKR implanted by two surgeons for the recommended indications. Methods: The first consecutive 512 cementless Phase 3 Oxford cemented UKRs implanted by two surgeons for the recommended indications between June 2004 and October 2013 were prospectively identified and followed up independently. All the procedures were carried out through a minimally invasive approach without eversion or dislocation of the patella. Patients were assessed clinically preoperatively and at one, two, five, seven and ten years after surgery with functional outcome scores and radiographs. Results: There were 8 reoperations of which 6 were revisions giving a 5 year survival of 98% (95% CI 94 - 100%). At a mean follow-up of 3.4 years (1.0 to 10.2) the mean OKS was 43 (SD 7), AKSS (objective) was 81 (SD 13) and AKSS (functional) was 86 (SD 17). The first 120 cases had a minimum follow up of five years (mean 5.9; range 5 - 10.2). In these patients the mean OKS was 41 (SD 8), AKSS (objective) was 81 (SD 14) and AKSS (functional) was 82 (SD 18). There were no femoral radiolucencies, and no complete tibial radiolucencies. 11% of tibial components had partial radiolucent lines; the remaining 89% had no radiolucencies. Conclusion: The clinical results are as good as or better than those previously reported for cemented fixation. The radiographic results are better with secure bony attachment to the implants in every case

Group formation for collaboration in exploratory learning using group technology techniques

Exploratory Learning Environments (ELEs) allow learners to approach a problem in different ways; they are particularly suitable for ill-defined problems where knowledge is less structured and open-ended exploration is allowed. Moreover, multiple solutions which are equally valid are possible and a common and efficient way to convey this is by promoting and supporting students’ collaboration. Successful collaboration, however, depends on forming groups in which the activity is relevant for all members of the group. In this paper we present a computational model for group formation for open-ended exploration in ELEs by modelling the various strategies that learners adopt to solve the same task. This is underpinned by Group Technology techniques that use as criteria the learners’ strategies and the similarity among them to form groups that match pedagogy considerations. The proposed mechanism is tested in an exploratory learning environment for mathematical generalisation