Neural Networks for Modeling and Control of Particle Accelerators

We describe some of the challenges of particle accelerator control, highlight recent advances in neural network techniques, discuss some promising avenues for incorporating neural networks into particle accelerator control systems, and describe a neural network-based control system that is being developed for resonance control of an RF electron gun at the Fermilab Accelerator Science and Technology (FAST) facility, including initial experimental results from a benchmark controller.Comment: 21 p

The publics of public health in Africa

How do we understand the public character of public health in contemporary Africa? What are the parameters of community engagement in health care delivery, medical research and disease control programmes? To what extent is public health in Africa a project led by African Governments? Through what political processes and deliberative practices can African publics influence the priorities of research in health sciences and interventions which aim in broad terms to improve the health of such publics? Drawing insight from empirical research conducted with African scientists, nurses, community members, clinical trialists and policy-makers, this special section examines the multiple ways in which the public comes into being around public health provisioning and investigation in sub-Saharan Africa, its role and political reach. Collectively, these papers show how contestation and negotiation around different ideas about who the public is and what being public means can lead to the emergence of conflicting understandings, with implications for who and what is seen to represent the public interest, and for the acceptance of research and other interventions

Construction and analysis of causally dynamic hybrid bond graphs

Engineering systems are frequently abstracted to models with discontinuous behaviour (such as a switch or contact), and a hybrid model is one which contains continuous and discontinuous behaviours. Bond graphs are an established physical modelling method, but there are several methods for constructing switched or ‘hybrid’ bond graphs, developed for either qualitative ‘structural’ analysis or efficient numerical simulation of engineering systems. This article proposes a general hybrid bond graph suitable for both. The controlled junction is adopted as an intuitive way of modelling a discontinuity in the model structure. This element gives rise to ‘dynamic causality’ that is facilitated by a new bond graph notation. From this model, the junction structure and state equations are derived and compared to those obtained by existing methods. The proposed model includes all possible modes of operation and can be represented by a single set of equations. The controlled junctions manifest as Boolean variables in the matrices of coefficients. The method is more compact and intuitive than existing methods and dispenses with the need to derive various modes of operation from a given reference representation. Hence, a method has been developed, which can reach common usage and form a platform for further study

Howard walnut trees can be brought into bearing without annual pruning

In traditionally managed Howard walnut orchards, trees are pruned annually during the orchard development phase, an expensive operation in terms of labor and prunings disposal costs. Our observations and some prior research by others had suggested that pruning may not be necessary in walnut. In a trial of pruned and unpruned hedgerow trees over 8 years, beginning a year after planting, we documented canopy growth, tree height, yield and nut quality characteristics and also the effects of fruit removal. Pruning altered canopy shape but did not lead to increases in canopy development, yield or nut quality. Although fruit removal stimulated more vegetative growth in both the pruned and unpruned treatments, fruit removal did not result in an increase in midday canopy photosynthetically active radiation interception or cumulative yield when fruit removal was stopped after year 4. After 8 years, there were no significant differences in tree height, nut quality or cumulative yield among any of the treatments, which suggests that not pruning young Howard orchards could provide a net benefit to growers

Captured by Evil: The Idea of Corruption in Law

Corruption is one of the most powerful words in the English language. When it comes to the treatment of corruption by law, however, corruption is a troubled concept. With increasing recognition of the costs of corruption for economic development, democratic governance, international aid programs, and other world goals, attempts to articulate what this destructive force is have led to an avalanche of theoretical writing. In the last fifteen years, corruption has been variously defined as the violation of law, a public servant\u27s breach of public duty, an agent\u27s betrayal of a principal\u27s interests, the pursuit of secrecy, the denial of equality in political influence, and other ways. In the end, however, all of these efforts fall short. Corruption is more than law-breaking: it is more than breaching public duties. To say that A is a thief or that A has breached his duty is not to say that A is corrupt. The latter is far more powerful, far more emotional, far more essential than the others. It is more than secrecy, or the denial of equal opportunity. It is a searing indictment, somehow, not only of A\u27s act but of A\u27s character. It is a statement not only of what A has done, but of what A has become. Corruption is, I argue, a far more powerful idea than these existing legal understandings have articulated: it is the idea of capture by evil, the possession of the individual by evil, in law. Just as we once believed in corruption of the blood in American law, which decreed that offspring of those who had committed crimes were believed to be irrevocably tainted by their parents\u27 depravity, so we still retain - through the idea of corruption - the belief that individual evil extends beyond acts of wrongdoing, or the denial of equal opportunity, or breach of the public trust. It is this idea of corruption, I argue - the idea of capture by evil - that, although unarticulated, drives our understandings of corruption in law. It drives our understanding of corrupt judges, who, once corrupt, we believe will act so in every case. It drives our understanding of campaign finance reform, where we fear deep corruption of the process from the occurrence of corrupt acts. It drives our understanding of corruption as a systemic effect and systemic influence, which presents institutional dangers that are greater than other crimes, and that requires purgation rather than simple law enforcement. This Article explores this deeper understanding of corruption, its impacts in areas such as judicial corruption and campaign finance reform, and its implications for the principle of the rule of law