Ants: Mobile Finite State Machines

Consider the Ants Nearby Treasure Search (ANTS) problem introduced by Feinerman, Korman, Lotker, and Sereni (PODC 2012), where $n$ mobile agents, initially placed at the origin of an infinite grid, collaboratively search for an adversarially hidden treasure. In this paper, the model of Feinerman et al. is adapted such that the agents are controlled by a (randomized) finite state machine: they possess a constant-size memory and are able to communicate with each other through constant-size messages. Despite the restriction to constant-size memory, we show that their collaborative performance remains the same by presenting a distributed algorithm that matches a lower bound established by Feinerman et al. on the run-time of any ANTS algorithm

Decision-making with children, young people, and parents

The origin and importance of support in decision-making in paediatric palliative care (PPC) is rooted in its primary goal: to reduce suffering and maintain and even improve the quality of life of seriously ill children and their families. Decisions take place throughout the trajectory of a child’s illness and many are straight forward and barely noticed. However, often at pivotal points such as changes in treatment plans and the focus of care, the outcomes of the decisions assume much more importance and how they are made becomes a significant task for the family and clinicians involved

Recovery of 150-250 MeV/nuc Cosmic Ray Helium Nuclei Intensities Between 2004-2010 Near the Earth, at Voyager 2 and Voyager 1 in the Heliosheath - A Two Zone Helioshpere

The recovery of cosmic ray He nuclei of energy ~150-250 MeV/nuc in solar cycle #23 from 2004 to 2010 has been followed at the Earth using IMP and ACE data and at V2 between 74-92 AU and also at V1 beyond the heliospheric termination shock (91-113 AU). The correlation coefficient between the intensities at the Earth and at V1 during this time period is remarkable (0.921), after allowing for a ~0.9 year delay due to the solar wind propagation time from the Earth to the outer heliosphere. To describe the intensity changes and to predict the absolute intensities measured at all three locations we have used a simple spherically symmetric (no drift) two-zone heliospheric transport model with specific values for the diffusion coefficient in both the inner and outer zones. The diffusion coefficient in the outer zone, assumed to be the heliosheath from about 90 to 120 (130) AU, is determined to be ~5 times smaller than that in the inner zone out to 90 AU. This means the Heliosheath acts much like a diffusing barrier in this model. The absolute magnitude of the intensities and the intensity changes at V1 and the Earth are described to within a few percent by a diffusion coefficient that varies with time by a factor ~4 in the inner zone and only a factor of ~1.5 in the outer zone over the time period from 2004-2010. For V2 the observed intensities follow a curve that is as much as 25% higher than the calculated intensities at the V2 radius and at times the observed V2 intensities are equal to those at V1. At least one-half of the difference between the calculated and observed intensities between V1 and V2 can be explained if the heliosphere is squashed by ~10% in distance (non-spherical) so that the HTS location is closer to the Sun in the direction of V2 compared to V1.Comment: 13 Pages, 8 Figure

Die Geburt neuer Marken : Zur Entwicklung von Marken auf der Basis der Theorien konzeptueller Kombinationen

Marken scheinen allgegenwärtig. Sie sind zum festen Bestandteil unserer hochentwickelten Wirtschaftskultur geworden. Mit Marken beeinflussen wir und werden wir beeinflusst – oftmals weit stärker als wir gemeinhin bereit sind zuzugeben: Wir verschenken keine Schokolade, wir verschenken „Merci“, weil wir uns bedanken möchten, oder Milka „Lila Herzen“, wenn wir unsere Zuneigung bekennen. Die wachsende Informationsüberlastung seitens der Konsumenten und eine ständig zunehmende qualitative Austauschbarkeit konkurrierender Angebote führen allerdings dazu, dass es neuen Die Geburt neuer Marken Zur Entwicklung von Marken auf der Basis der Theorien konzeptueller Kombinationen Marken immer seltener gelingt, erfolgreich einen Platz in den Köpfen der Verbraucher zu erringen. Viele Marken verschwinden deshalb genauso rasch wieder aus den Supermarktregalen wie sie dort erschienen sind. Dieser Beitrag beschäftigt sich mit dem Problem, wie der Markenaufbau unter solch ungünstigen Rahmenbedingungen optimiert werden kann. Aufbauend auf den kognitionspsychologischen Theorien konzeptueller Kombinationen werden Techniken für einen effektiven Markenaufbau abgeleitet und in einer empirischen Studie hinsichtlich ihrer Wirksamkeit getestet

Ursprung, Konstruktion und Dekonstruktion mythischer Verwandtschaft in Athen und Ephesos

In dem Beitrag werden zwei ältere, bislang unentdeckte Mythenversionen rekonstruiert, die die “barbarischen” Amazonen als Einwanderinnen, Ahnfrauen und Gründungsheroinen in positiver Konnotation vorführen. Im Zentrum steht zum einen die am Ende des 6. Jahrhundert v. Chr. beliebte Erzählung von Theseus und Antiope, die mit alten Kultmalen in Athen in Verbindung gebracht werden kann. Zum anderen sind Ergebnisse neuerer Grabungen im Artemisheiligtum von Ephesos zu nennen, wo Befunde früharchaischer Zeit (7. Jahrhundert v. Chr.) ebenfalls Anlass für die Entstehung einer älteren Gründungslegende geliefert haben könnten. Ihre Funktion als identitätsstiftende Migrationsmythen wurde im 5. Jahrhundert v. Chr. unter Einfluss der Perserkriege und der daraus resultierenden hegemonialen Interessen Athens aufgegeben und von der Griechen-Barbaren-Dualität überlagert. Dies gelang deshalb so gut, weil die alten Raumbezüge nun nicht mehr präsent waren

Event-Driven Motion Compensation in Positron Emission Tomography: Development of a Clinically Applicable Method

Positron emission tomography (PET) is a well-established functional imaging method used in nuclear medicine. It allows for retrieving information about biochemical and physiological processes in vivo. The currently possible spatial resolution of PET is about 5 mm for brain acquisitions and about 8 mm for whole-body acquisitions, while recent improvements in image reconstruction point to a resolution of 2 mm in the near future. Typical acquisition times range from minutes to hours due to the low signal-to-noise ratio of the measuring principle, as well as due to the monitoring of the metabolism of the patient over a certain time. Therefore, patient motion increasingly limits the possible spatial resolution of PET. In addition, patient immobilisations are only of limited benefit in this context. Thus, patient motion leads to a relevant resolution degradation and incorrect quantification of metabolic parameters. The present work describes the utilisation of a novel motion compensation method for clinical brain PET acquisitions. By using an external motion tracking system, information about the head motion of a patient is continuously acquired during a PET acquisition. Based on the motion information, a newly developed event-based motion compensation algorithm performs spatial transformations of all registered coincidence events, thus utilising the raw data of a PET system - the so-called `list-mode´ data. For routine acquisition of this raw data, methods have been developed which allow for the first time to acquire list-mode data from an ECAT Exact HR+ PET scanner within an acceptable time frame. Furthermore, methods for acquiring the patient motion in clinical routine and methods for an automatic analysis of the registered motion have been developed. For the clinical integration of the aforementioned motion compensation approach, the development of additional methods (e.g. graphical user interfaces) was also part of this work. After development, optimisation and integration of the event-based motion compensation in clinical use, analyses with example data sets have been performed. Noticeable changes could be demonstrated by analysis of the qualitative and quantitative effects after the motion compensation. From a qualitative point of view, image artefacts have been eliminated, while quantitatively, the results of a tracer kinetics analysis of a FDOPA acquisition showed relevant changes in the R0k3 rates of an irreversible reference tissue two compartment model. Thus, it could be shown that an integration of a motion compensation method which is based on the utilisation of the raw data of a PET scanner, as well as the use of an external motion tracking system, is not only reasonable and possible for clinical use, but also shows relevant qualitative and quantitative improvement in PET imaging.Die Positronen-Emissions-Tomographie (PET) ist ein in der Nuklearmedizin etabliertes funktionelles Schnittbildverfahren, das es erlaubt Informationen über biochemische und physiologische Prozesse in vivo zu erhalten. Die derzeit erreichbare räumliche Auflösung des Verfahrens beträgt etwa 5 mm für Hirnaufnahmen und etwa 8 mm für Ganzkörperaufnahmen, wobei erste verbesserte Bildrekonstruktionsverfahren eine Machbarkeit von 2 mm Auflösung in Zukunft möglich erscheinen lassen. Durch das geringe Signal/Rausch-Verhältnis des Messverfahrens, aber auch durch die Tatsache, dass der Stoffwechsel des Patienten über einen längeren Zeitraum betrachtet wird, betragen typische PET-Aufnahmezeiten mehrere Minuten bis Stunden. Dies hat zur Folge, dass Patientenbewegungen zunehmend die erreichbare räumliche Auflösung dieses Schnittbildverfahrens limitieren. Eine Immobilisierung des Patienten zur Reduzierung dieser Effekte ist hierbei nur bedingt hilfreich. Es kommt daher zu einer relevanten Auflösungsverschlechterung sowie zu einer Verfälschung der quantifizierten Stoffwechselparameter. Die vorliegende Arbeit beschreibt die Nutzbarmachung eines neuartigen Bewegungskorrekturverfahrens für klinische PET-Hirnaufnahmen. Mittels eines externen Bewegungsverfolgungssystems wird während einer PET-Untersuchung kontinuierlich die Kopfbewegung des Patienten registriert. Anhand dieser Bewegungsdaten führt ein neu entwickelter event-basierter Bewegungskorrekturalgorithmus eine räumliche Korrektur aller registrierten Koinzidenzereignisse aus und nutzt somit die als "List-Mode" bekannten Rohdaten eines PET Systems. Für die Akquisition dieser Daten wurden eigens Methoden entwickelt, die es erstmals erlauben, diese Rohdaten von einem ECAT Exact HR+ PET Scanner innerhalb eines akzeptablen Zeitraumes zu erhalten. Des Weiteren wurden Methoden für die klinische Akquisition der Bewegungsdaten sowie für die automatische Auswertung dieser Daten entwickelt. Ebenfalls Teil der Arbeit waren die Entwicklung von Methoden zur Integration in die klinische Routine (z.B. graphische Nutzeroberflächen). Nach der Entwicklung, Optimierung und Integration der event-basierten Bewegungskorrektur für die klinische Nutzung wurden Analysen anhand von Beispieldatensätzen vorgenommen. Es zeigten sich bei der Auswertung sowohl der qualitativen als auch der quantitativen Effekte deutliche Änderungen. In qualitativer Hinsicht wurden Bildartefakte eliminiert; bei der quantitativen Auswertung einer FDOPA Messung zeigte sich eine revelante Änderung der R0k3 Einstromraten eines irreversiblen Zweikompartment-Modells mit Referenzgewebe. Es konnte somit gezeigt werden, dass eine Integration einer Bewegungskorrektur unter Zuhilfenahme der Rohdaten eines PET Systems sowie unter Nutzung eines externen Verfolgungssystems nicht nur sinnvoll und in der klinischen Routine machbar ist, sondern auch zu maßgeblichen qualitativen und quantitativen Verbesserungen in der PET-Bildgebung beitragen kann

Novel Approaches for Retrofitting Heat Exchanger Networks Subject to Varying Operating Conditions

The process industry is responsible for a significant share of the final industrial energy use in Sweden. In particular, the pulp and paper industry accounts for more than 50 %. In this context, a number of studies have shown that there is a substantial potential for energy savings in the pulp and paper industry. In particular, increased heat recovery is an important measure for increasing energy efficiency. Industrial process plants usually include heat recovery systems that are built to transfer heat between different process streams. Such heat recovery systems consist of Heat Exchanger Networks (HENs) which can be characterized by a high degree of complexity, e.g. through stream splits, recycle and closed circulation loops.Increasing heat recovery, e.g. by redesigning (retrofitting) the existing heat recovery system, can contribute significantly to meeting energy efficiency improvement targets for industrial process plants. One issue to consider when screening retrofit design options is that industrial heat recovery systems must be able to handle external variations, e.g. in inlet temperatures or heat capacity flow rates, in such a way that operational targets are reached. Consequently, there is a need for systematic retrofitting methodologies applicable to HENs subject to variation in operating conditions. The aim of this thesis is to propose new approaches for retrofitting HENs operating in multiple periods.Three different approaches have been developed and published in three papers appended to this thesis which allow for retrofitting HENs operating in multiple periods. These approaches can be applied independently and are applicable to HENs commonly present in process industry, e.g. pulp and paper industry. All approaches have in common that they require structural retrofit design proposals as input. For the structural proposal generation, graphical approaches (e.g. Pinch-based) may be utilized in order to take advantage of the designer interaction during the design process. The three approaches propose different strategies to evaluate and ensure feasibility of the design proposals when operating conditions vary, e.g. by means of design modifications. In this context, feasibility is achieved if predefined target values, e.g. stream target temperatures, can be reached for the entire span of variations. Furthermore, different strategies help the designer to identify the most promising proposal (or proposals) among the provided ones with respect to a defined objective, e.g. most energy-efficient or most cost-efficient

Fiber Intake In Hemodialysis Patients And Its Effects On Symptoms

On average 30 million adults are diagnosed with chronic kidney disease (CKD) in the United States (National Kidney Foundation, 2017). Patients in late stage kidney disease and on dialysis are placed on a restrictive diet to aid in the treatment of their disease. There are adverse symptoms associated with dialysis including nausea, constipation, diarrhea and fatigue. Fiber has been shown to decrease gastrointestinal symptoms such as reducing constipation and inflammation in the body in healthy populations. This study examined 19 hemodialysis dialysis patients and their fiber intake in relation to a variety of symptoms such as constipation, nausea, vomiting, diarrhea, appetite and dry mouth. Results determined that there is a positive correlation between soluble fiber and diarrhea severity (p=0.047). There were other variables that were approaching significance such as dietary fiber and diarrhea frequency and severity and soluble fiber and diarrhea frequency. In conclusion there was a connection between fiber and diarrhea severity, however, more research is required to conclude that nutrition interventions with fiber would be beneficial for this demographic

'I have to live with the decisions I make': laying a foundation for decision making for children with life-limiting conditions and life-threatening illnesses.

The relationship between parents and clinician is critical to the care and treatment of children with life-limiting conditions (LLCs) and life-threatening illnesses (LTIs). This relationship is built and maintained largely in consultations. In this article we lay out factors that bear on the success of clinical consultations and the maintenance of the essential clinician-parent relationship at progression or deterioration of LLCs or LTIs. We suggest an approach to engaging parents in conversations about care and treatment that recognises and appreciates the dilemmas which clinicians and parents face and in so doing provides a way for everyone to live with the decisions that are made. A close analysis of a consultation at progression and excerpts of encounters among parents, clinician and researcher are used to illustrate our approach to research, analysis and development of recommendations for clinical practice