Program slice metrics and their potential role in DSL design, position paper

The advantages a DSL and the benefits its use potentially brings imply that informed decisions on the design of a domain specific language are of paramount importance for its use. We believe that the foundations of such decisions should be informed by analysis of data empirically collected from systems to highlight salient features that should then form the basis of a DSL. To support this theory, we describe an empirical study of a large OSS called Barcode, written in C, and from which we collected two well-known 'slice' based metrics. We analyzed multiple versions of the system and sliced its functions in three separate ways (i.e., input, output and global variables). The purpose of the study was to try and identify sensitivities and traits in those metrics that might inform features of a potential slice-based DSL. Results indicated that cohesion was adversely affected through the use of global variables and that appreciation of the role of function inputs and outputs can be revealed through slicing. The study presented is motivated primarily by the problems with current tools and interfaces experienced directly by the authors in extracting slicing data and the need to promote the benefits that analysis of slice data and slicing in general can offer.

Effective-fourth-order resonator based MASH bandpass sigma-delta modulators

Two novel effective-fourth-order (eighth-order) resonator based MASH (MultistAge noise SHaping) bandpass Σ-Δ modulators are introduced at the behavioural level and subsequently examined by simulations utilising the ALTA SPW environment. The considered bandpass configurations have in their loop filter a cascade of standard second-order resonator structures in order to achieve appropriate noise shaping. The quantisation noise in each stage is suppressed by feeding the error of each section into the input of the following stage. It is demonstrated in this paper that the quadruple effective-first-order cascade configuration has significantly better performance as well as conforming more closely with theory in comparison with the effective-second-order effective-second-order cascade. The superior performance of the former can be attributed to the cumulative effect of the multi-bit outputs as well as the presence of more notch filters.

Image, video and 3D data registration: medical, satellite and video processing applications with quality metrics

Data registration refers to a series of techniques for matching or bringing similar objects or datasets together into alignment. These techniques enjoy widespread use in a diverse variety of applications, such as video coding, tracking, object and face detection and recognition, surveillance and satellite imaging, medical image analysis and structure from motion. Registration methods are as numerous as their manifold uses, from pixel level and block or feature based methods to Fourier domain methods. This book is focused on providing algorithms and image and video techniques for registration and quality performance metrics. The authors provide various assessment metrics for measuring registration quality alongside analyses of registration techniques, introducing and explaining both familiar and state–of–the–art registration methodologies used in a variety of targeted applications.

Physical Education or Playtime: which is more effective at promoting physical activity in primary school children?

Background School physical education (PE) and playtime provide important opportunities for physical activity (PA). However, little research has assessed PA during primary school PE using accelerometry or compared PA during different lesson types. There is also a lack of research comparing PA during PE and playtime, despite suggestions that playtime promotes more PA. The primary aim of this study was to determine which types of PE lesson are most facilitative of PA. The secondary aim was to determine whether children are more active during PE or playtime. Methods Descriptive and fitness data were assessed in 20 children aged 8-9years from a single school. Over eight consecutive weeks PA was assessed during PE lessons, which were classified as either team games or movement activities. At the mid-week of data collection playtime PA was also assessed. PA was assessed using accelerometry and the percentage of time spent in moderate to vigorous PA (MVPA) calculated. Paired t-tests were used to compare MVPA during movement lessons and team games lessons and during PE and playtime. Results Children spent 9.5% of PE lessons in MVPA and engaged in significantly more MVPA during team games (P < 0.001). MVPA was also significantly higher during PE than playtime (P < 0.01). Conclusions Children do not engage in sufficient PA during PE, but are most active during team games lessons; whilst PA during playtime is lower than PE. Interventions to increase PA during both PE and playtime are therefore required. PE interventions should target games lessons as they dominate the curriculum, encourage most PA and present the greatest potential for change. Playtime interventions should encourage participation in active games through the provision of playground equipment and markings.

The Wilderness Expedition: An effective life course intervention to improve young peoples well-being and connectedness to nature

It is well understood that wilderness expeditions improve well-being; however, there is little supporting quantitative data. The aim of this study was to measure the impact of wilderness expeditions on self-esteem (SE) and connectedness to nature (CN) and assess whether benefits varied according to participant and expedition characteristics. SE and CN were assessed pre– and post–wilderness expeditions in 130 adolescents using Rosenberg’s SE scale and the state CN scale. Two-way ANOVA revealed significant increases in SE and CN (p < .001) as a result of single expeditions. There was also an interaction effect of expedition and gender on SE (p < .05). Males had a higher SE at the start but female SE increased most. Linear regression revealed that living environment, gender, and the length and location of the expedition did not contribute to changes in SE and CN. Regular contact with natural environments will improve adolescent well-being, with the largest improvements in females.