A computer-based test item bank using a Rasch model

Chapter SevenZadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk

A Swiss Pocket Knife for Computability

This research is about operational- and complexity-oriented aspects of classical foundations of computability theory. The approach is to re-examine some classical theorems and constructions, but with new criteria for success that are natural from a programming language perspective. Three cornerstones of computability theory are the S-m-ntheorem; Turing's "universal machine"; and Kleene's second recursion theorem. In today's programming language parlance these are respectively partial evaluation, self-interpretation, and reflection. In retrospect it is fascinating that Kleene's 1938 proof is constructive; and in essence builds a self-reproducing program. Computability theory originated in the 1930s, long before the invention of computers and programs. Its emphasis was on delimiting the boundaries of computability. Some milestones include 1936 (Turing), 1938 (Kleene), 1967 (isomorphism of programming languages), 1985 (partial evaluation), 1989 (theory implementation), 1993 (efficient self-interpretation) and 2006 (term register machines). The "Swiss pocket knife" of the title is a programming language that allows efficient computer implementation of all three computability cornerstones, emphasising the third: Kleene's second recursion theorem. We describe experiments with a tree-based computational model aiming for both fast program generation and fast execution of the generated programs.Comment: In Proceedings Festschrift for Dave Schmidt, arXiv:1309.455

A framework for documenting and analyzing life-cycle costs using a simple network based representation

The introduction of high reliability systems combined with new ways of operating complex systems, particularly in aircraft design and operation has received much attention in recent years. Some systems are now being introduced into service, however, justifying such systems on a financial basis is difficult and may act to limit the rate of introduction on new products. Conventional life cycle costing based on a hierarchical cost breakdown structure is poor at recording and analysing the cost implications of introducing new technologies that have effects that span more than one phase in the life cycle. There is a risk that too much emphasis is put on ‘faith’ that a candidate technology will reduce cost because the cost analysis methods lack descriptive and analytical power. We describe an approach to representing the costs associated with introducing new technologies and evaluating their total cost. Our aim was to facilitate the comparison of different technological choices in new product development, with a particular interest in how the perceived benefits of enhanced reliability systems can be shown in a way that is inclusive, objective and easy to understand

Potential for material systems beyond Superalloys

Systems beyond nickel based superalloys are being researched and considered. The opportunities and challenges for these materials will be considered along with the likely compromises likely to be necessary. There is a continued pressure for cost and environmental reasons to reduce the emissions and this leads to the requirement for high temperature materials. These requirements have been met by continued improvements in nickel based superalloys for many years. However, for reasons including sustainability, cost, density and phase instability the scope for further improvement is very limited. There are therefore opportunities for successor systems. The challenges should not be underestimated. Gas turbine materials need to have a balance of physical, mechanical and environmental properties to meet the required safety and performance requirements as well as having acceptable cost and a sustainable supply. Successor material systems will have some different characteristics to nickel based superalloys and some changes to design philosophy are likely to be required. A good mutual understanding between materials and design communities is therefore required

The Surgical Release of Dupuytren's Contracture Using Multiple Transverse Incisions.

Dupuytren's contracture is a condition commonly encountered by hand surgeons, although it is rare in the Asian population. Various surgical procedures for Dupuytren's contracture have been reported, and the outcomes vary according to the treatment modalities. We report the treatment results of segmental fasciectomies with multiple transverse incisions for patients with Dupuytren's contracture. The cases of seven patients who underwent multiple segmental fasciectomies with multiple transverse incisions for Dupuytren's contracture from 2006 to 2011 were reviewed retrospectively. Multiple transverse incisions to the severe contracture sites were performed initially, and additional incisions to the metacarpophalangeal (MCP) joints, and the proximal interphalangeal (PIP) joints were performed if necessary. Segmental fasciectomies by removing the fibromatous nodules or cords between the incision lines were performed and the wound margins were approximated. The mean range of motion of the involved MCP joints and PIP joints was fully recovered. During the follow-up periods, there was no evidence of recurrence or progression of disease. Multiple transverse incisions for Dupuytren's contracture are technically challenging, and require a high skill level of hand surgeons. However, we achieved excellent correction of contractures with no associated complications. Therefore, segmental fasciectomies with multiple transverse incisions can be a good treatment option for Dupuytren's contracture

Combination of content analysis and context features for digital photograph retrieval.

In recent years digital cameras have seen an enormous rise in popularity, leading to a huge increase in the quantity of digital photos being taken. This brings with it the challenge of organising these large collections. The MediAssist project uses date/time and GPS location for the organisation of personal collections. However, this context information is not always sufficient to support retrieval when faced with a large, shared, archive made up of photos from a number of users. We present work in this paper which retrieves photos of known objects (buildings, monuments) using both location information and content-based retrieval tools from the AceToolbox. We show that for this retrieval scenario, where a user is searching for photos of a known building or monument in a large shared collection, content-based techniques can offer a significant improvement over ranking based on context (specifically location) alone

How effective is community physical activity promotion in areas of deprivation for inactive adults? A pragmatic observational evaluation of the 'Active Herts' physical activity programme

Background There is a high prevalence of inactivity in UK adults and many suffer from comorbid conditions. These frequently co-exist in areas of higher socio-economic deprivation. There is a need to test the effectiveness, acceptability, and sustainability of physical activity programmes in this population. Method Active Herts recruited inactive adults (N=435) with one or more risk factors for cardiovascular disease and/or mild-to-moderate mental health conditions, and followed up at 3 and 6 months after baseline. In two areas programme-users received a behaviour change technique booklet, consultations, a booster phone call, motivational text messages, and signposting to 12 weeks of exercise classes (standard intervention). In another two areas programme-users also received 12 weeks of free tailored exercise classes, with optional exercise ‘buddies’ (enhanced intervention). Mixed ANOVAs analysed changes in physical activity, sporting participation, sitting (primary outcomes), mental wellbeing, health perception, and COM-B measures (secondary outcomes). Secondary analyses explored whether COM-B measures predicted moderate-to-vigorous physical activity (MVPA) at baseline, 3, and 6 months, and changes at 3 and 6 months using path analyses. Results At both timepoints, physical activity (3 months, η2 = .17; 6 months, η2 = .18), sporting participation (3 months, η2 = .22; 6 months, η2 = .17), sitting time (3 months, η2 = .08; 6 months, η2 = .06), and several secondary outcomes (e.g. wellbeing) improved regardless of group. COM-B related indicators explained MVPA performance better after 3 (R2=18%) and 6 (R2=15%) months than at baseline (R2=8%), but changes in MVPA were weakly predicted (3 months, R2=5%; 6 months, R2=7%). Self-monitoring was key in driving MVPA performance and change. Conclusions and Implications Active Herts improved activity levels at 3 and 6 months providing preliminary evidence that such interventions, delivered in real world settings, can change the behaviour and wellbeing of residents living in areas of deprivation.Peer reviewedFinal Published versio