Academic literature on the topic 'Zero-cost abstractions'

The increasing complexity and modularity of contemporary systems, paired with increasing parameter variabilities, makes the availability of flexible and robust, yet efficient, module-level interconnections instrumental. Delay-insensitive codes are very attractive in this context. There is considerable literature on this topic that classifies delay-insensitive communication channels according to the protocols (return-to-zero versus non-return-to-zero) and with respect to the codes (constant-weight versus systematic), with each solution having its specific pros and cons. From a higher abstraction, however, these protocols and codes represent corner cases of a more comprehensive solution space, and an exploration of this space promises to yield interesting new approaches. This is exactly what we do in this paper. More specifically, we present a novel coding scheme that combines the benefits of constant-weight codes, namely simple completion detection, with those of systematic codes, namely zero-effort decoding. We elaborate an approach for composing efficient “Partially Systematic Constant Weight” codes for a given data word length. In addition, we explore cost-efficient and orphan-free implementations of completion detectors for both, as well as suitable encoders and decoders. With respect to the protocols, we investigate the use of multiple spacers in return-to-zero protocols. We show that having a choice between multiple spacers can be beneficial with respect to energy efficiency. Alternatively, the freedom to choose one of multiple spacers can be leveraged to transfer information, thus turning the original return-to-zero protocol into a (very basic version of a) non-return-to-zero protocol. Again, this intermediate solution can combine benefits from both extremes. For all proposed solutions we provide quantitative comparisons that cover the whole relevant design space. In particular, we derive coding efficiency, power efficiency, as well as area effort for pipelined and non-pipelined communication channels. This not only gives evidence for the benefits and limitations of the presented novel schemes—our hope is that this paper can serve as a reference for designers seeking an optimized delay-insensitive code/protocol/implementation for their specific application.

AbstractIn interventions for at-risk children, Tom Dishion strongly exhorted programs that are short term, cost-effective, and delivered in families’ own communities, just as resilience researchers underscore the need for programs that provide ongoing support for children's primary caregivers, and are implementable on a large scale. Presented here are preliminary results on a short-term intervention for mothers, the Authentic Connections Virtual Groups. A previous randomized trial of the in-person version of this program, conducted with mothers at high risk for stress and burnout, showed significant benefits. There had been zero dropouts across the 3-month program, and participants showed significant improvements on psychological indices as well as cortisol, even 3 months after the program ended. In the present study, virtual groups were conducted with five sets of women, all white-collar professionals with highly stressful, exacting careers, and most also primary caregivers of their children. Again, there were zero dropouts. Mean satisfaction ratings were 9.6 of 10, and the Net Promoter Score (promoters vs. detractors) fell in the “world class” range. To illuminate mechanisms of change, participants’ responses to open-ended questions on the groups’ value are presented verbatim. Recurrently mentioned were the development of new, authentic connections and invaluable ongoing support. These results, with the low costs and ease of women's attendance, attest to the value of expanding offerings such as these, toward benefiting even more highly stressed mothers themselves as well as the children for whose care they are responsible.

AbstractIn this paper, a bioinspired, compact, cost-effective autonomous underwater vehicle system is presented. Designed to operate in a heterogeneous, multivehicle collaboration hierarchy, the presented vehicle design features 3D printing technology to enable fast fabrication with a complex internal structure. Similar to a previous vehicle prototype, this system generates propulsive forces by expelling unsteady, pulsed jets, inspired by the locomotion of cephalopods and jellyfish. The novel thrusters enable the vehicle to be fully actuated in horizontal plane motions, without sacrificing the low-forward-drag, slender vehicle profile. By successively ingesting water and expelling finite water jets, periodic actuation forces are generated at all possible vehicle velocities, eliminating the need for control surfaces used in many conventional underwater vehicle designs. A semiactive buoyancy control system, inspired by the nautilus, adjusts the vehicle depth by passively allowing water flowing into and actively expelling water out of an internal bladder. A compact embedded system is developed to achieve the control and sensing capabilities necessary for multiagent interactions with the minimum required processing power and at a low energy cost. The new vehicle design also showcases an underwater optical communication system for short-range, high-speed data transmission, supplementing the conventional acoustic communication system. Experimental results show that, with the thruster motors powered at a 60% duty-cycle, the new vehicle is able to achieve a 1/4 zero-radius turn in 3.5 s and one-body-width sway translation in 2.5 s.

In this paper we present an application of AI search techniques to a class of problems that arise in transportation systems analysis. Rather than adapting the time-space network formulation typically used in Operations Research, we propose a discrete dynamic network to represent a scheduled service network. In a discrete dynamic network, there are finite, discrete, predetermined possibilities for moving from one vertex to another. Visiting a vertex has a cost (possibly zero), which may depend both on how the vertex was reached and how it will be left.We describe the DYNET search algorithm for finding optimal paths in discrete dynamic networks. DYNET has been implemented in a working system (TRAINS) which searches the entire Dutch railway services network. An optimal path in a discrete dynamic network makes us arrive at our destination as early as possible (given our planned earliest departure time), and given this earliest arrival time (eat), will allow us to leave as late as possible, thereby guaranteeing a shortest path relative to the eat. DYNET first conducts a forward search to find the earliest possible arrival time, then a backward search which uses results of the forward search, to find the latest departure to arrive at that eat. Various AI techniques (symmetries, abstraction spaces, distance estimates, etc.) improve the performance of DYNET.

Abstract. This paper addresses the issue of "what reservoir storage capacity is required to maintain a yield with a given probability of failure?". It is an important issue in terms of construction and cost. HYDROMED offers a solution based on the modified Gould probability matrix method. This method has the advantage of sampling all years data without reference to the sequence and is therefore particularly suitable for catchments with patchy data. In the HYDROMED model, the probability of failure is calculated on a monthly basis. The model has been applied to the El-Gouazine catchment in Tunisia using a long rainfall record from Kairouan together with the estimated Hortonian runoff, class A pan evaporation data and estimated abstraction data. Generally, the probability of failure differed from winter to summer. Generally, the probability of failure approaches zero when the reservoir capacity is 500,000 m3. The 25% probability of failure (75% success) is achieved with a reservoir capacity of 58,000 m3 in June and 95,000 m3 in January. The probability of failure for a 240,000 m3 capacity reservoir (closer to storage capacity of El-Gouazine 233,000 m3), is approximately 5% in November, December and January, 3% in March, and 1.1% in May and June. Consequently there is no high risk of El-Gouazine being unable to meet its requirements at a capacity of 233,000 m3. Subsequently the benefit, in terms of probability of failure, by increasing the reservoir volume of El-Gouazine to greater than the 250,000 m3 is not high. This is important for the design engineers and the funding organizations. However, the analysis is based on the existing water abstraction policy, absence of siltation rate data and on the assumption that the present climate will prevail during the lifetime of the reservoir. Should these conditions change, a new analysis should be carried out. Keywords: HYDROMED, reservoir, storage capacity, probability of failure, Mediterranean

AbstractIn the common dung or black scavenger fly Sepsis cynipsea (Diptera: Sepsidae) several morphological and behavioural male and female traits interact during mating. Previous studies show that males attempt to mount females without courtship, females use vigorous shaking behaviour in response to male mounting, the duration of shaking is an indicator of both direct and indirect female choice and sexual conflict, and larger males enjoy a mating advantage. We conducted a quantitative genetic paternal half sib study to investigate the genetic underpinnings of these traits, notably body size (the preferred trait) and the associated female preference, and to assess the relative importance of various models generally proposed to account for the evolution of sexually selected traits. Several morphological traits and female shaking duration were heritable, thus meeting a key requirement of all sexual selection models. In contrast, two traits indicative of male persistence in mating were not. Male longevity was also heritable and negatively correlated with his mating effort, suggesting a mating cost. However, the crucial genetic correlation between male body size and female shaking duration, predicted to be negative by both 'good genes' and Fisherian models and positive by the sexual conflict (or chase-away) model, was zero. This could be because of low power, or because of constraints imposed by the genetic correlation structure. Based on our rsults we conclude that discriminating sexual selection models by sole means of quantitative genetics is difficult, if not impossible.

AbstractIn central Europe, barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.], has commonly been found in humid lowland areas. As a result of the introduction of new crops and farming practices, in the northwest Carpathians, E. crus-galli has spread from lowland (<200 m altitude) to highland (>400 m altitude) areas. We collected seed samples from local populations lying at a distance of approximately 5 km from each other and lined up along transects following the flows of two rivers. The rivers first flow through the valleys separated by mountain ridges and eventually flow into a common lowland. After ripening, the seeds of all populations were germinated at 25 C under long-day conditions. Only the seeds of some lowland populations germinated up to 75%. The frequency of germinated seeds decreased as the altitude where the population was collected increased, and above 200 m above sea level, germination was mostly zero. We then studied the phenological and morphological differentiation of plants from the original (lowland) and recently occupied (highland) areas. Seeds of the lowest and the highest localities lying on the transect of each river were sown in a common garden experiment. In plants from the highland localities, heading and seed dispersal were earlier, while tiller height and tiller mass were lower than in plants from the lowland localities. Seed mass produced per tiller in the lowland and highland plants was similar, and as a result, highland plants allocated a larger proportion of body mass to seed production than did lowland plants. Echinochloa crus-galli populations from highland localities thus produce their progeny earlier and at a lower energy cost than populations from lowland localities. The plasticity of phenological characters likely facilitated adaptation during E. crus-galli spread from lowlands to highlands. Similar adaptations in plant phenology may contribute to the spread of E. crus-galli in other geographic areas.

In study was conducted analysis and systematic studies of war syndromes, the end of the 20th and early 21st centuries ("Vietnamese syndrome", "Persian Gulf syndrome", "Afghan syndrome," etc.). For the first time are presented the systemic symptoms of the hybrid war syndrome (hybrid conflict) on the basis of the analysis, the application of the method of historical analogies, comparison, systematization and interpretation of facts, abstraction and concretization. For the first time, the presence of the following stages of its development in the process of formation of PTSD has been proven: the "pre-PTSD", the latent phase "soft PTSD" (which already takes place, but obviously does not manifest itself and can be detected only by instrumental (hardware) methods) and "formed PTSD" (as a rule, one that is completely formed, clearly manifested, stable, multisymptomatic, and deployed, which, in the absence of its timely detection and treatment, is more likely to be transformed into a post-traumatic personality disorder). The issues of informational and cognitive trauma of personnel and population were considered on the basis of the analysis of the striking factors of information and cognitive weapons and the peculiarities of their salvage in the Hybrid War. We identified and described in our model of formation of PTSD in the context of the hybrid war "zero" - "entry into military service" stage and the three main stages of the emergence and formation of the PTSD. The first stage is "preparatory": Phases: 1) General training; 2) training in the units in the conditions most close to combat (primary "Vaccinations" from PTSD); 3) Combat coordination of units (secondary "Vaccinations" from PTSD). The second stage of "stay in the crisis zone": 1) phase - sending to the area of military action; 2) participation in military action; 3) retirement. The third stage "Return from the combat zone". Particular emphasis should be put on other models of PTSD formation in specialists who do not take direct participation in battles, but are in a state of high nervous-psychological stress. Stress is due the influence of responsibility for the effectiveness of use in the area of military action or in the enemy territory of high-cost, high-tech means on which the effectiveness of action depends in general, and the lives of combatants (for example, LAC crews and, in particular, UAV operators (2nd model) and military pilots flying aircraft (airplanes / helicopters) (3rd moth model). The first and second stages of the formation of PTSD in them are similar to the above-mentioned one model of the formation of PTSD. Differences with the 1st model and between the second and third models develop in the third stage. It has also been established that PTSD may occur immediately after a traumatic event, or can lead to a negative long-term symptom and show symptoms that are sufficient for the diagnosis of PTSD (or the conditions / illness associated with it), even over the years.

Abstract Background: BAY 81-8973 (Kovaltry®, Bayer) is an unmodified full-length recombinant FVIII launched in 2016 in Europe and the US for the prophylaxis and treatment of bleeds in patients with hemophilia A. BAY 81-8973 has been extensively studied in clinical trials, which have demonstrated consistent efficacy and safety in both children and adults in the LEOPOLD trials, and since launch, 6750 patient-years of experience have been accumulated. Pharmacokinetic analyses have demonstrated an increased half-life for BAY 81-8973 compared with standard factor VIII products (rFVIII-FS and rFVIII [rAHF-PFM]). Real world evidence demonstrating the effectiveness and safety of BAY 81-8973 across age groups is being collected, though aggregated international data have yet to be published. The primary objective of this analysis was to describe the effectiveness of BAY 81-8973 in the real world setting in children and adults from Europe and the US, as captured in the Cost of Haemophilia: a Socioeconomic Survey (CHESS) study. Methods: The CHESS 2018 program investigated the economic and psychological burden of moderate and severe hemophilia (FVIII < 5%) in Europe and the USA. The pediatric cohort (CHESS Pediatric) included 1050 males aged 1-17 years, with moderate or severe hemophilia, while CHESS US included 568 adults with severe hemophilia aged > 18 years. Clinical and patient reported data were obtained via medical chart abstraction and cross-sectional surveys sent to both physicians and patients. Data were collected between December 2017 and April 2018, and captured 12 months of clinical retrospective data. The current study is a descriptive analysis of patients treated with BAY 81-8973 from the CHESS pediatric and adult cohorts. Results: At the data cut off (May 2018), 49 patients were being treated with BAY 81-8973. The majority of pediatric patients were aged 6-11 years (51.7%, n=15), while 17.2% (n=5) were aged 0-5 years and 31% (n=9) were aged 12-17 years. In the adult US cohort, most (60%, n=12) were aged 18-35 years, 35% (n=7) were aged 36-59 years, and 5% (n=1) were aged > 60 years. The vast majority of patients across cohorts had severe disease (93.1% of children and 100% of adults); however, 89.7% (26/29) of children and 80% (16/20) of adults had no target joints. In this population, 75.9% (22/29) of children and 55.0% (11/20) of adults were receiving regular prophylaxis with BAY 81-8973. Children and adults on prophylaxis both had a mean (± SD) of 2 (± 1) infusions/week, with median (Q1; Q3) weekly doses of 84 (67; 110) and 62 (29; 144) IU/kg, respectively. Overall, 20.7% (6/29) of children and 35% (7/20) of adults treated with BAY 81-8973 had zero bleeds and mean annualized bleed rate (ABR) was 2.66 (± 2.06) in children and 1.45 (± 1) in adults; 68.9% (20/29) of children and 95.0% (19/20) of adults had experienced ≤ 3 bleeds in the previous year. There were no reports of inhibitor development in either the pediatric or adult cohorts while on BAY 81-8973. Conclusions: These observations suggest that BAY 81-8973 is an effective and well-tolerated treatment for adults and children with moderate and severe hemophilia A, with ABR < 3 in children and < 2 in adults and with many patients free from bleeds despite only 67% of patients studied receiving regular prophylaxis. These data confirm the observations from the LEOPOLD trials, suggest BAY 81-8973 provides good protection from bleeding across a range of patient types in routine clinical practice and illustrate how the established pharmacokinetic profile of BAY 81-8973 translates to clinical benefits for patients with hemophilia A. Study supported by Bayer Disclosures Hirst: Bayer: Employment. Rauchensteiner:Bayer: Employment.

AbstractGenerative type abstractions – present in Haskell, OCaml, and other languages – are useful concepts to help prevent programmer errors. They serve to create new types that are distinct at compile time but share a run-time representation with some base type. We present a new mechanism that allows for zero-cost conversions between generative type abstractions and their representations, even when such types are deeply nested. We prove type safety in the presence of these conversions and have implemented our work in GHC.

Cílem této práce je vývoj dvoukanálového kontroléru krokových motorů. V rámci práce je popsán jak vývoj elektroniky, tak vývoj příslušného software. Elektronika kontrolŕu je založena na mikrokontroléru STM32F405 a driverů krokových motorů vyráběných firmou Trinamic. Pro komunikaci s nadřazenými systémy je implementován protokol CANOpen a sběrnice I\textsuperscript{2}C a USB. Elektronika byla navržena v software KiCAD and využívá čtyřvrstvého plošného spoje a moderních výrobních technologií. Co se týká software, byl vyvinut jak firmware pro mikrokontrolér, tak software pro ovládání kontroléru. Obě části software využívají programovacího jazyka Rust, který se zaměřuje na bezpečnost práce s pamětí, rychlost a zero-cost abstrakce. Sekundárním cílem této práce je ukázat, jak lze tento programovací jazyk s výhodou použít pro programování nízkoúrovňového embedded software. Firmware kontroléru implementuje nezávislé řízení pohybu obou os kontroléru a to jak v rychlostním, tak v pozičním režimu a zároveň implementuje bezpečnostní funkce pro případy selhání komunikace. Výsledný kontrolér by měl být použit v rámcí výzkumné skupiny Robotiky a Umělé Inteligence a studenty na Ústavu Automatizace FEKT VUT.

Embedded systems are commonplace, often with real-time requirements, limited resources and increasingly complex workloads with high demands on security and reliability. The complexity of these systems calls for extensive developer experience and many tools has been created to aid in the development of the software running on such devices. One of these tools, the Real-Time For the Masses (RTFM) concurrency framework developed at Luleå University of Technology (LTU), is built upon a pre-existing, well established and theoretically underpinned execution model providing deadlock free execution and strong guarantees about correctness. The framework is further enhanced by the memory safety provided by Rust, a modern systems programming language. This thesis documents the work done towards improving the framework by studying the possibility to make it extendable. For this, a model of the present layout is required, which in turn requires a solid understanding of Rust's way to structure code. To realise such a large structural change it was advisable to join the open-source RTFM community as a core developer. This role included new responsibilities and required work within different areas of the framework, not only directly related to the primary goal. It also provided the insight that in order to reach the desired extendable structure, many other improvements had to be done first, including the removal of large experimental features. To aid the development, usage of state of the art Continuous Integration testing (CI) were key. Changes to such systems are also part of the development process. The name of the project changed in the middle of this thesis work, going from RTFM to Real-Time Interrupt-driven Concurrency (RTIC). The implemented features and usability fixes detailed in this thesis improves the user experience for embedded system developers resulting in increased productivity while making the development process of such systems more accessible. These general improvements will be part of the next release of the framework. A version v0.6.0-alpha.0 of the framework has been released for testing. The experiences gained related to open-source project governance during this work are also presented.