844 research outputs found
Very large-scale neighborhoods with performance guarantees for minimizing makespan on parallel machines
We study the problem of minimizing the makespan on m parallel machines. We introduce a very large-scale neighborhood of exponential size (in the number of machines) that is based on a matching in a complete graph. The idea is to partition the jobs assigned to the same machine into two sets. This partitioning is done for every machine with some chosen rule to receive 2m parts. A new assignment is received by putting to every machine exactly two parts. The neighborhood Nsplit consists of all possible rearrangements of the parts to the machines. The best assignment of Nsplit can be calculated in time O(mlogm) by determining the perfect matching having minimum maximal edge weight in an improvement graph, where the vertices correspond to parts and the weights on the edges correspond to the sum of the processing times of the jobs belonging to the parts. Additionally, we examine local optima in this neighborhood and in combinations with other neighborhoods. We derive performance guarantees for these local optima.operations research and management science;
Making as a means to re-engage disengaged young people back into education:a case study
Lickable Cities is a research project that responds to the recent and overwhelming abundance of non-calls for gustatory exploration of urban spaces. In this paper, we share experiences from nearly three years of nonrepresentational, absurdist, and impractical research. During that time, we licked hundreds of surfaces, infrastructures, and interfaces in cities around the world. We en-countered many challenges from thinking with, designing for, and interfacing through taste, including: - how can and should we grapple with contamination?, and - how might lickable interfaces influence more-than-humans? We discuss these challenges to compassionately question the existing framework for designing with taste in HCI
THE SUCCESS OF A SOCCER KICK DEPENDS ON RUN UP DECELERATION
The purpose of the study was to relate the motion of the centre of mass (CoM) during run ups in soccer full insteps kicks with the obtained ball speeds. Nineteen experienced play-ers performed kicks onto the goal and their full body kinematics as well as ball motion were analysed in three dimensions using two high speed video cameras. Higher decel-erations of the CoM with the last step are associated with higher ball velocities and higher thigh angular impulses. Those data suggest, that an intensive breaking of the CoM veloc-ity provides a prerequisite to transfer a portion of the CoM impulse into angular impulse of the thigh. High angular impulse of the thigh however can be beneficial for fast instep kicks
Antimicrobial-drug use and changes in resistance in Streptococcus pneumoniae.
Resistance of Streptococcus pneumoniae to antimicrobial drugs is increasing. To investigate the relationship between antimicrobial use and susceptibility of S. pneumoniae isolates at 24 U.S. medical centers, we obtained data on outpatient antimicrobial-drug use for the regions surrounding 23 of these centers. We found an association between decreased penicillin susceptibility and use of beta-lactam antimicrobial drugs
Send in the clowns : scoping non-representational theory as ally and method to foster inclusiveness in digital Iinnovation
Send in the clowns is the account of a post-disciplinary, critical, creative practise that over the course of 6 years explored the subject of ‘digital innovation’ and ‘innovating in the digital’. The digital in this context is interpreted in the widest possible sense and includes any instance where cybertechnology relates to/with humans. This framing has put forward my proposed concept of the digiscape; a phenomenological interpretation of cyber-technology. In 3 distinct interventions (Ch.3,4,5) I have appropriated literatures on inventive methods, sustainable design and diffraction for my thinking. Through the lessons learned from each intervention I have constructed my own interpretation of non-representational theory and methods. I make the case that these can be a fertile ground for emancipatory politics concerning research and development in/on the digital. Seeking to test my claim that such approaches can be deemed valuable to practising innovators, I have submitted my hypothesis together with a non-representational experiment (‘Lickable Cities’) to CHI 2018 [a] (the pre-eminent journal in the field of Human-ComputerInteraction). The submission was accepted. Ch.6 discusses the implications of this on the scholarship of non-representational-theory and philosophy. Thus my conclusion is that non-representational approaches are indeed of value to innovators as a means to catalyse a type of awareness(es) that makes otherwise inutterable questions possible. I am claiming that through fostering alliances across methods, traditions, disciplines, writing styles, ethnicities, media and epistemologies - with the help of non-representational theory - more inclusive research is enabled and method itself can be invigorated (Ch.7). As my work is concerned with knowing about knowing, and knowing about ways of knowing, my work is firmly placed within Science and Technology Studies (STS) and is written for an STS audience
Send in the Clowns: Scoping Non-Representational Theory as Ally and Method to Foster Inclusiveness in Digital Innovation
Send in the clowns is the account of a post-disciplinary, critical, creative practise that over the course of 6 years explored the subject of ‘digital innovation’ and ‘innovating in the digital’. The digital in this context is interpreted in the widest possible sense and includes any instance where cybertechnology relates to/with humans. This framing has put forward my proposed concept of the digiscape; a phenomenological interpretation of cyber-technology.
In 3 distinct interventions (Ch.3,4,5) I have appropriated literatures on inventive methods, sustainable design and diffraction for my thinking. Through the lessons learned from each intervention I have constructed my own interpretation of non-representational theory and methods. I make the case that these can be a fertile ground for emancipatory politics concerning research and development in/on the digital.
Seeking to test my claim that such approaches can be deemed valuable to practising innovators, I have submitted my hypothesis together with a non-representational experiment (‘Lickable Cities’) to CHI 2018 [a] (the pre-eminent journal in the field of Human-ComputerInteraction). The submission was accepted. Ch.6 discusses the implications of this on the scholarship of non-representational-theory and philosophy.
Thus myconclusion is that non-representational approaches are indeed of value to innovators as a means to catalyse a type of awareness(es) that makes otherwise inutterable questions possible. I am claiming that through fostering alliances across methods, traditions, disciplines, writing styles, ethnicities, media and epistemologies- with the help of non-representational theory- more inclusive research is enabled and method itself can be invigorated (Ch.7).
As mywork is concerned with knowing about knowing, and knowing about ways of knowing, myworkis firmly placed within Science and Technology Studies (STS) and is written for an STS audience.
[a]The ‘ACM’ Conference on ‘Human Factors in Computing Systems’, the principal venue for research in the f ield of ’Human-Computer Interaction’ (HCI
Controlled lasing from active optomechanical resonators
Planar microcavities with distributed Bragg reflectors (DBRs) host, besides
confined optical modes, also mechanical resonances due to stop bands in the
phonon dispersion relation of the DBRs. These resonances have frequencies in
the sub-terahertz (10E10-10E11 Hz) range with quality factors exceeding 1000.
The interaction of photons and phonons in such optomechanical systems can be
drastically enhanced, opening a new route toward manipulation of light. Here we
implemented active semiconducting layers into the microcavity to obtain a
vertical-cavity surface-emitting laser (VCSEL). Thereby three resonant
excitations -photons, phonons, and electrons- can interact strongly with each
other providing control of the VCSEL laser emission: a picosecond strain pulse
injected into the VCSEL excites long-living mechanical resonances therein. As a
result, modulation of the lasing intensity at frequencies up to 40 GHz is
observed. From these findings prospective applications such as THz laser
control and stimulated phonon emission may emerge
Impact of Multiple Factors on the Degree of Tinnitus Distress
Objective: The primary cause of subjective tinnitus is a dysfunction of the
auditory system; however, the degree of distress tinnitus causes depends
largely on the psychological status of the patient. Our goal was to attempt to
associate the grade of tinnitus-related distress with the psychological
distress, physical, or psychological discomfort patients experienced, as well
as potentially relevant social parameters, through a simultaneous analysis of
these factors. Methods: We determined the level of tinnitus-related distress
in 531 tinnitus patients using the German version of the tinnitus
questionnaire (TQ). In addition, we used the Perceived Stress Questionnaire
(PSQ); General Depression Scale Allgemeine Depression Skala (ADS), Berlin Mood
Questionnaire (BSF); somatic symptoms inventory (BI), and SF-8 health survey
as well as general information collected through a medical history. Results:
The TQ score significantly correlated with a score obtained using PSQ, ADS,
BSF, BI, and SF-8 alongside psychosocial factors such as age, gender, and
marital status. The level of hearing loss and the auditory properties of the
specific tinnitus combined with perceived stress and the degree of depressive
mood and somatic discomfort of a patient were identified as medium-strong
predictors of chronic tinnitus. Social factors such as gender, age, or marital
status also had an impact on the degree of tinnitus distress. The results that
were obtained were implemented in a specific cortical distress network model.
Conclusions: Using a large representative sample of patients with chronic
tinnitus permitted a simultaneous statistical measurement of psychometric and
audiological parameters in predicting tinnitus distress. We demonstrate that
single factors can be distinguished in a manner that explains their causative
association and influence on the induction of tinnitus-related distress
Psychological Treatment Effects Unrelated to Hair-Cortisol and Hair-BDNF Levels in Chronic Tinnitus
Background: Currently, there are no objective markers to measure treatment efficacy in chronic (distressing) tinnitus. This study explores whether stress-related biomarkers cortisol and brain-derived neurotrophic factor (BDNF) measured in hair samples of chronic tinnitus patients change after compact multimodal tinnitus-specific cognitive behavioral therapy.
Methods: In this longitudinal study, hair-cortisol and hair-BDNF levels, self-reported tinnitus-related distress (Tinnitus Questionnaire; TQ), and perceived stress (Perceived Stress Questionnaire; PSQ-20) were assessed before and 3 months after 5 days of treatment in N = 80 chronic tinnitus patients. Linear mixed-effects models with backward elimination were used to assess treatment-induced changes, and a cross-lagged panel model (structural equation model) was used for additional exploratory analysis of the temporal associations between TQ and hair-BDNF.
Results: At follow-up, a reduction in TQ (p < 0.001) and PSQ-20 scores (p = 0.045) was observed, which was not influenced by baseline hair-cortisol or hair-BDNF levels. No changes in biomarker levels were observed after treatment. The exploratory analysis tentatively suggests that a directional effect of baseline TQ scores on hair-BDNF levels at follow-up (trend; p = 0.070) was more likely than the opposite directional effect of baseline hair-BDNF levels on TQ scores at follow-up (n.s.).
Discussion: While the treatment effectively reduced tinnitus-related distress and perceived stress in chronic tinnitus patients, this effect was not mirrored in biological changes. However, the lack of changes in hair-cortisol and hair-BDNF levels might have been influenced by the treatment duration, follow-up interval, or confounding medical factors, and therefore must be interpreted with caution. The relationship between tinnitus-related distress and hair-BDNF levels should be explored further to obtain a better understanding of stress-related effects in chronic tinnitus
Carbon allocation and carbon isotope fluxes in the plant-soil-atmosphere continuum: a review
The terrestrial carbon (C) cycle has received increasing interest over the past few decades, however, there is still a lack of understanding of the fate of newly assimilated C allocated within plants and to the soil, stored within ecosystems and lost to the atmosphere. Stable carbon isotope studies can give novel insights into these issues. In this review we provide an overview of an emerging picture of plant-soil-atmosphere C fluxes, as based on C isotope studies, and identify processes determining related C isotope signatures. The first part of the review focuses on isotopic fractionation processes within plants during and after photosynthesis. The second major part elaborates on plant-internal and plant-rhizosphere C allocation patterns at different time scales (diel, seasonal, interannual), including the speed of C transfer and time lags in the coupling of assimilation and respiration, as well as the magnitude and controls of plant-soil C allocation and respiratory fluxes. Plant responses to changing environmental conditions, the functional relationship between the physiological and phenological status of plants and C transfer, and interactions between C, water and nutrient dynamics are discussed. The role of the C counterflow from the rhizosphere to the aboveground parts of the plants, e.g. via CO<sub>2</sub> dissolved in the xylem water or as xylem-transported sugars, is highlighted. The third part is centered around belowground C turnover, focusing especially on above- and belowground litter inputs, soil organic matter formation and turnover, production and loss of dissolved organic C, soil respiration and CO<sub>2</sub> fixation by soil microbes. Furthermore, plant controls on microbial communities and activity via exudates and litter production as well as microbial community effects on C mineralization are reviewed. A further part of the paper is dedicated to physical interactions between soil CO<sub>2</sub> and the soil matrix, such as CO<sub>2</sub> diffusion and dissolution processes within the soil profile. Finally, we highlight state-of-the-art stable isotope methodologies and their latest developments. From the presented evidence we conclude that there exists a tight coupling of physical, chemical and biological processes involved in C cycling and C isotope fluxes in the plant-soil-atmosphere system. Generally, research using information from C isotopes allows an integrated view of the different processes involved. However, complex interactions among the range of processes complicate or currently impede the interpretation of isotopic signals in CO<sub>2</sub> or organic compounds at the plant and ecosystem level. This review tries to identify present knowledge gaps in correctly interpreting carbon stable isotope signals in the plant-soil-atmosphere system and how future research approaches could contribute to closing these gaps
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