Karl Küpfmüller, 1928: an early time-domain, closed-loop, stability criterion

Karl Küpfmüller was a German engineer who worked for eight years during the 1920s at Siemens & Halske in Berlin. During that time he carried out fundamental work on telegraphy and telephony, network theory, and the systems theory of electrical signal transmission. Like his contemporary in the US, Harry Nyquist, he derived fundamental results in information transmission and closed-loop modelling. In contrast to Nyquist, though, his name is not well-known in the English-speaking world. Indeed, little has appeared in English about him or his work – although his pioneering results in systems theory informed later American work, particularly through the contributions of Ernst Guillemin, a prolific writer of highly influential student texts and a great engineering educator at MIT, who was well-acquainted with the ideas of Küpfmüller (and other German electrical engineers)

Early Detection and Intervention in Audiology

"Early hearing detection and intervention (EHDI) is the gold standard for any practising audiologist, and for families of infants and children with hearing impairment. Yet EHDI remains a significant challenge for Africa, and various initiatives are in place to address this gap in transferring policy into practice within the southern African context. Early Detection and Intervention in Audiology: An African Perspective aims to address the diversity of factors in southern Africa that presents unique challenges to teaching and research in this field. The South African government’s heightened focus on increasing access to health care, which includes ongoing Early Childhood Development (ECD) programmes, makes this an opportune time for establishing and documenting evidence-based research for current undergraduate and postgraduate students. Detailed case studies pay careful attention to contextual relevance and responsiveness to both identification and intervention in hearing impairment. With diverse contributions from local and international experts, but always with an African perspective, this textbook will be an essential resource for students, researchers and practitioners.

Trade-offs, condition dependence and stopover site selection by migrating sandpipers

Western sandpipers Calidris mauri on southward migration fly over the Gulf of Alaska to the Strait of Georgia, British Columbia, where they stop for a few days to replenish reserves before continuing. In the Strait, individuals captured on the extensive tidal mudflats of the Fraser estuary (∼25000 ha) are significantly heavier (2.71 g, or >10% of lean body mass) than those captured on the small (<100 ha) mudflat of nearby Sidney Island. Previous work has shown that the difference cannot be attributed to seasonal timing, size, age or gender effects, and here we compare predictions made by six hypotheses about a diverse set of data to explain why, partway through a migratory journey of ∼10000 km, birds have such different body masses at two stopover sites within 40 km of each other. The ‘trade-off’ hypothesis – that the large Fraser estuary offers safety from predators, but a lower fattening rate, while the small Sidney Island site is more dangerous, but offers a higher fattening rate – made six successful predictions, all of which were upheld by the data. All other hypotheses failed at least one prediction. We infer that calidrid sandpipers arriving in the Strait of Georgia with little fat remaining (and therefore low body mass) choose to take advantage of the high feeding rate at small sites like Sidney Island because they are less vulnerable to avian predators than are individuals with higher fat reserves, who instead elect to feed at large open sites like the Fraser estuary mudflats

Från koja till plan

This thesis concerns questions regarding how children’s perspectives on the outdoor environment can be approached in a planning context. Attention is drawn to the general understanding of childhood and the definition of outdoor environment as variables in different planning contexts. Together these variables define in which way children become visible in the planning context. Children’s participation is emphasized in contemporary planning. This thesis argues that understanding and insights concerning children’s experiences and understanding of their own places can create complementary lines of communication. The first article provides the empirical and methodological point of departure. Through walkabouts with children, questions are developed concerning children’s use and experiences of outdoor environments. These questions are compared and related to problems, insights and experiences that planners have concerning environments for children. Parts of two perspectives are described in order to elucidate some of the problems that can arise due to differences between a child’s perspective and a planner’s perspective. In the second article children’s own places is the pivot. Through in depth studies of children’s dens it is shown that finding a suitable place, collecting, sorting and manipulating with environment and accessible materials are crucial parts of starting a den making process and appropriating a place as one’s own. Specific examples are put forward which show the close relationship between children’s experience and understanding of the outdoor environment and their construction and design of dens. Children’s dens are used to exemplify and clarify the difference between children’s perspectives and planner’s perspectives. The last article is concerned with the theoretical and practical analysis of these questions. Through interviews, studies of planning documents and reflections on my own planning experience an analysis is made of the importance of maps and plans as tools in the planning process. It is argued that the bias of these tools emphasizes and reinforces the visual point of departure to the physical environment and outdoor places, while children’s multi-sensuous and acting oriented point of departure is difficult to handle and process in maps and plans. A practical contribution is suggested on how to improve insights and understanding of children’s perspectives in planning contexts

The relationships between corporate meeting planner's personality traits and their choices of meeting places

This study is to determine the influence of personality on the novelty preference for corporate meeting destination choice. The Big-Five model of personality which consists of five traits namely openness, conscientiousness, extraversion,agreeableness, and neuroticism was employed to operationalise the personality construct. A total of 75 corporate meeting planners drawn from public listed service organisations were involved. The main method of data collection was questionnaire survey and multiple regression analysis was employed as the main statistical analysis. The results revealed that only openness (positively) and agreeableness (negatively) contributed significantly to the prediction of novelty preference for corporate meeting destination choice. This study, which also seeks to determine the relationships between some demographical variables and novelty preference, found that demographical information is not a good predictor of meeting destination choice. The main implication of this study is pertaining to the segmentation and targeting of the corporate meeting market. This study also helps in bridging the gap between tourism marketing and organisational research

Objections to statutory proposals for school organisation: potential changes to the time available for objections to published statutory proposals which involve changes to schools, new schools, or school closures (consultation document)

Welsh Assembly Government consultation documen

Armenian Neighbours (600-1045)

Publisher PD

Spatial evolution of the US urban system.

We examine spatial features of the evolution of the US urban system usingUS Census data for 1900 – 1990 with non-parametric kernel estimation techniques that accommodate the complexity of the urban system. We consider spatial features of the location of cities and city outcomes in terms of population and wages. Our results suggest a number of interesting puzzles. In particular, we find that city location is essentially a random process and that interactions between cities do not help determine the size of a city. Both of these findings contradict our theoretical priors about the role of geography (physical and economic) in determining city outcomes. More detailed study suggests some solutions that allow us to restore a role for geography but a number of puzzles remain.

The Determination of Dendrite Coherency Point Characteristics Using Three New Methods for Aluminum Alloys

The aim of this work is to give an overview of existing methods and to introduce three new methods for the determination of the Dendrite Coherency Point (DCP) for AlSi10Mg alloys, as well as to compare the acquired values of DCP based on a thermal analysis and on the analysis of cooling curves working with only one thermocouple. Additionally, the impact of alloying and contaminant elements on the DCP will be also studied. The first two proposed methods employ the higher order derivatives of the cooling curves. The DCP was determined as the crossing point of the second and third derivative curves plotted versus time (method 1) or that of the temperature (method 2) with the zero line just after the maximum liquidus temperature. The third proposed method is based on the determination of the crossing point of the third solid fraction derivative curve with the zero line, corresponding to a minimum of the second derivative. A Taguchi design for the experiments was developed to study the DCP values in the AlSi10Mg alloy. The DCP temperature values of the test alloys were compared with the DCP temperatures predicted by the previous methods and the influence of the major and minor alloying elements and contaminants over the DCP. The new processes obtained a correlation factor r2 from 0.954 and 0.979 and a standard deviation from 1.84 to 2.6 °C. The obtained correlation values are higher or similar than those obtained using previous methods with an easier way to define the DCP, allowing for a better automation of the accuracy of DCP determination. The use of derivative curves plotted versus temperature employed in the last two proposed methods, where the test samples did not have an influence over the registration curves, is proposed to have a better accuracy than those of the previously described methods.This work has been partially funded by the Basque Government through the ETORGAI programme ZE-2016/00018 and from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No. 296024

The Educational Gender Gap in Latin America and the Caribbean

This paper analyzes the evolution of gender differences in school attendance and attainment in Latin America and the Caribbean, for both adults who left the educational system and children in school. For individuals 21 years old and above the paper uses a cohort analysis of school attainment. The results indicate that the schooling gap has closed for the cohort born at the end of the 1960s. Since then, the gap has reversed such that within the cohort born in 1980, females have, on average, ¼ of a schooling year more than males. During the four decades of birth cohorts of our analysis (1940-1980) the gender gap in attainment has moved in favor of females at a pace of 0. 27 years of schooling per decade. A decomposition exercise suggests that the changes in the schooling gap are mainly explained by the educational attainment of females at the higher levels, rather than improvements in the early years of education. An analysis of attendance and attainment among girls and boys between 6 and 18, for Bolivia, Guatemala, Mexico and Peru (the countries that have not closed the gap in adult schooling attainment) reveals noticeable gender differences, favoring boys, only among older children of the lowest income quintiles and indigenous ethnicity.