Complexity Bounds for Ordinal-Based Termination

`What more than its truth do we know if we have a proof of a theorem in a given formal system?' We examine Kreisel's question in the particular context of program termination proofs, with an eye to deriving complexity bounds on program running times. Our main tool for this are length function theorems, which provide complexity bounds on the use of well quasi orders. We illustrate how to prove such theorems in the simple yet until now untreated case of ordinals. We show how to apply this new theorem to derive complexity bounds on programs when they are proven to terminate thanks to a ranking function into some ordinal.Comment: Invited talk at the 8th International Workshop on Reachability Problems (RP 2014, 22-24 September 2014, Oxford

Generating socially appropriate tutorial dialog

Analysis of student-tutor coaching dialogs suggest that good human tutors attend to and attempt to influence the motivational state of learners. Moreover, they are sensitive to the social face of the learner, and seek to mitigate the potential face threat of their comments. This paper describes a dialog generator for pedagogical agents that takes motivation and face threat factors into account. This enables the agent to interact with learners in a socially appropriate fashion, and foster intrinsic motivation on the part of the learner, which in turn may lead to more positive learner affective states

Endogenous fantasy and learning in digital games.

Many people believe that educational games are effective because they motivate children to actively engage in a learning activity as part of playing the game. However, seminal work by Malone (1981), exploring the motivational aspects of digital games, concluded that the educational effectiveness of a digital game depends on the way in which learning content is integrated into the fantasy context of the game. In particular, he claimed that content which is intrinsically related to the fantasy will produce better learning than that which is merely extrinsically related. However, this distinction between intrinsic and extrinsic (or endogenous and exogenous) fantasy is a concept that has developed a confused standing over the following years. This paper will address this confusion by providing a review and critique of the empirical and theoretical foundations of endogenous fantasy, and its relevance to creating educational digital games. Substantial concerns are raised about the empirical basis of this work and a theoretical critique of endogenous fantasy is offered, concluding that endogenous fantasy is a misnomer, in so far as the "integral and continuing relationship" of fantasy cannot be justified as a critical means of improving the effectiveness of educational digital games. An alternative perspective on the intrinsic integration of learning content is described, incorporating game mechanics, flow and representations

Caregiver strain on informal caregivers when providing care for older patients undergoing major abdominal surgery:A longitudinal prospective cohort study

Background:  Health-care systems nowadays rely on complementary patient care by informal caregivers. The need for, and burden on, informal caregivers will likely increase in the upcoming years. This study aimed to examine the burden on caregivers when providing care for elderly patients undergoing major abdominal surgery. Methods:  A single-centre longitudinal cohort study was conducted between November 2015 and June 2018 in the Amphia hospital in Breda, the Netherlands. Patients aged 70+ undergoing elective surgery for colorectal carcinoma (CRC) or an abdominal aortic aneurysm (AAA) were included in this study. Informal caregiver burden was assessed and compared over time using the Caregiver Strain Index (CSI) at the outpatient clinic visit, at discharge, 2 weeks post-discharge and after 6 and 12 months. The effects of patient- and caregiver-related factors on the experienced caregiver strain were examined. Results: CSI scores of 248 caregivers were significantly increased at discharge (3.5 vs 2.6; p < 0.001) and 2 weeks post-discharge (3.3 vs 2.6; p < 0.001). After 12 months, scores dropped below baseline scores (1.8 vs 2.6; p = 0.012). The highest strain was observed 2 weeks post-discharge for AAA patients and at discharge for CRC patients. Older age, physical or cognitive impairment and burden of comorbidity were associated with an increased caregiver strain at baseline. Type of surgery was independently associated with the change in mean CSI scores over time; a bigger change in caregiver burden is observed after open surgery. Conclusion:  In the early postoperative period, perceived caregiver strain was significantly increased. Psychological support for caregivers may be advisable, with timing of this support depending on diagnosis and patient-related factors. Trial registration: This manuscript was retrospectively registered on 05-04-2016 in the Netherlands Trial Register (NTR5932). http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=593

Switching Coal-Fired Thermal Power Plant to Composite Fuel for Recovering Industrial and Municipal Waste: Combustion Characteristics, Emissions, and Economic Effect

Combustion characteristics were studied experimentally for single droplets of fuel slurries based on wet coal processing waste with municipal solid waste components (cardboard, plastic, rubber, and wood) and used turbine oil. We established the ignition delay time for three various groups of fuel compositions in motionless air at 600–1000 °C. The minimum values are 3 s, and the maximum ones are 25 s. The maximum temperatures in the droplet vicinity reach 1300 °C during fuel combustion for compositions with 10% of used oil. The combustion temperatures of fuel compositions without oil are 200–300 °C lower. The concentrations of anthropogenic emissions in flue gases do not exceed those from dry coal combustion. Adding used oils to composite fuels reduces the concentrations of dioxins and furans in flue gases when municipal solid waste in the fuel burns out due to high combustion temperatures. Based on the experimental research findings, we have elaborated a strategy of combined industrial and municipal waste recovery by burning it as part of composite fuels, as illustrated by three neighboring regions of the Russian Federation with different industrial structures and levels of social development. This strategy suggests switching three typical coal-fired thermal power plants (one in each of the regions) to composite liquid fuel. It will reduce the hazard of waste to the environment and decrease the consumption of high-quality coals for power generation. Implementing the developed strategy for 25 years will save 145 Mt of coal and recover 190–260 Mt of waste. The positive economic effect, considering the modernization of fuel handling systems at thermal power plants and the construction of a fuel preparation plant, will make up 5.7 to 6.9 billion dollars, or 65–78%, respectively, of the main costs of three thermal power plants operating on coal within the identical period

Motivation profiles in sport: A self-determination theory perspective

The present study examined the link between motivation profiles among adult sports participants and the outcomes of enjoyment, effort, positive and negative affect, attitude toward sport participation, intention to continue sport participation, satisfaction, and persistence in sport. Two samples of participants (n = 590 and n = 555) completed the Sport Motivation Scale and a range of self-report measures to assess the outcome variables. Exploratory cluster analyses applied to Sample 1 and confirmatory cluster analysis applied to Sample 2 identified two clusters of sport participants. The first comprised participants with high scores on both non self-determined and self-determined motives. The second comprised participants with high scores on self-determined motives but low scores on non self- determined motives. Participants in the first cluster scored higher on all outcome variables. The results are discussed with reference to a more in-depth understanding of the motivation dynamics of sport participation based on Self-Determination Theory

Measurement and modeling of the acoustic field near an underwater vehicle and implications for acoustic source localization

This article was published in the Journal of the Acoustical Society of America [© Acoustical Society of America] and is also available at: http://asadl.org/The performance of traditional techniques of passive localization in ocean acoustics such as time-of-arrival (phase differences) and amplitude ratios measured by multiple receivers may be degraded when the receivers are placed on an underwater vehicle due to effects of scattering. However, knowledge of the interference pattern caused by scattering provides a potential enhancement to traditional source localization techniques. Results based on a study using data from a multi-element receiving array mounted on the inner shroud of an autonomous underwater vehicle show that scattering causes the localization ambiguities side lobes to decrease in overall level and to move closer to the true source location, thereby improving localization performance, for signals in the frequency band 2–8 kHz. These measurements are compared with numerical modeling results from a two-dimensional time domain finite difference scheme for scattering from two fluid-loaded cylindrical shells. Measured and numerically modeled results are presented for multiple source aspect angles and frequencies. Matched field processing techniques quantify the source localization capabilities for both measurements and numerical modeling output. © 2007 Acoustical Society of America

Patient and public involvement in scope development for a palliative care health technology assessment in Europe

Background Patient and Public Involvement (PPI) helps to ensure that study findings are useful to end users but is under-developed in Health Technology Assessment (HTA). "INTEGRATE-HTA, (a co-funded European Union project -grant agreement 30614) is developing new methods to assess complex health technologies and applying these in a palliative care case study. Having experienced the intended and unintended consequences of palliative care services, which vary widely across Europe, patients in six countries (England, Germany, Italy, Netherlands, Norway and Poland) provided valuable insights and advice for scope development. Aims To establish PPI in a palliative care HTA. Methods As PPI to assist early scope development in HTA is novel, each country implemented PPI methods as appropriate locally. One of two advocated methods was used, either a qualitative research approach or seeking the views of patients, relatives, carers or patient representatives as research partners. Using a qualitative approach, 21 individual, face-face patient interviews were conducted and analysed thematically. When patients were research partners, an adapted version of the EUnetHTA core model guided 30 face-face discussions. Thematic analysis and conceptual mapping identified key issues. Findings PPI in palliative care requires researchers to have cultural awareness of the acceptability of engaging in discussions around dying in each country. Ensuring positive PPI experiences and effective participation by acknowledging patient knowledge and experience whilst establishing a two-way flow of information in the HTA process is essential. Partnership working between researchers and patients, stakeholder evaluation and remuneration when involved as partners is important. Conclusions PPI was successfully implemented in each country, assisting patient-centred scope development and identification of important issues related to palliative care. Although there is much to be gained from PPI, methods of PPI engagement require further development. All PPI methods have advantages and limitations which must be considered in light of local needs, resources and culture

Action planning with two-handed tools

In tool use, the intended external goals have to be transformed into bodily movements by taking into account the target-to-movement mapping implemented by the tool. In bimanual tool use, this mapping may depend on the part of the tool that is operated and the effector used (e.g. the left and right hand at the handle bar moving in opposite directions in order to generate the same bicycle movement). In our study, we investigated whether participants represent the behaviour of the tool or only the effector-specific mapping when using two-handed tools. In three experiments, participants touched target locations with a two-jointed lever, using either the left or the right hand. In one condition, the joint of the lever was constant and switching between hands was associated with switching the target-to-movement-mapping, whereas in another condition, switching between hands was associated with switching the joint, but the target-to-movement-mapping remained constant. Results indicate pronounced costs of switching hands in the condition with constant joint, whereas they were smaller with constant target-to-movement mapping. These results suggest that participants have tool-independent representations of the effector-specific mappings