LLukas22/scidocs huggingface dataset:
Experimental, theoretical, and computational investigation of separated nozzle flows

A detailed experimental, theoretical, and computational study of separated nozzle flows has been conducted. Experimental testing was performed at the NASA Langley 16-Foot Transonic Tunnel Complex. As part of a comprehensive static performance investigation, force, moment, and pressure measurements were made and schlieren flow visualization was obtained for a subscale, non-axisymmetric, two-dimensional, convergentdivergent nozzle. In addition, two-dimensional numerical simulations were run using the computational fluid dynamics code PAB3D with two-equation turbulence closure and algebraic Reynolds stress modeling. For reference, experimental and computational results were compared with theoretical predictions based on one-dimensional gas dynamics and an approximate integral momentum boundary layer method. Experimental results from this study indicate that offdesign overexpanded nozzle flow was dominated by shock induced boundary layer separation, which was divided into two distinct flow regimes; threedimensional separation with partial reattachment, and fully detached two-dimensional separation. The test nozzle was observed to go through a marked transition in passing from one regime to the other. In all cases, separation provided a significant increase in static thrust efficiency compared to the ideal prediction. Results indicate that with controlled separation, the entire overexpanded range of nozzle performance would be within 10% of the peak thrust efficiency. By offering savings in weight and complexity over a conventional mechanical exhaust system, this may allow a fixed geometry nozzle to cover an entire flight envelope. The computational simulation was in excellent agreement with experimental data over most of the test range, and did a good job of modeling internal flow and thrust performance. An exception occurred at low nozzle pressure ratios, where the two-dimensional computational model was inconsistent with the threedimensional separation observed in the experiment. In * Aerospace Engineer, Configuration Aerodynamics Branch, Aeroand Gas-Dynamics Division. Member A I M Copyright
Using Anti-Ant-like Agents to Generate Test Threads from the UML Diagrams

The problem of generating the test cases is one of the most important issues in the software testing research and practice. Test threads, especially the thin-threads which are the usage scenarios in a software system, are frequently used to generate test cases for the scenario-based software testing. However, the derivation of the test threads is usually a manual and labor-intensive task. In this paper, we propose an automated approach using anti-ant-like agents to directly generate test threads from the UML artifacts. The generated test threads can then be used to generate and to prioritize the test cases for scenario-based software testing.
Revisiting QRS Detection Methodologies for Portable, Wearable, Battery-Operated, and Wireless ECG Systems

Cardiovascular diseases are the number one cause of death worldwide. Currently, portable battery-operated systems such as mobile phones with wireless ECG sensors have the potential to be used in continuous cardiac function assessment that can be easily integrated into daily life. These portable point-of-care diagnostic systems can therefore help unveil and treat cardiovascular diseases. The basis for ECG analysis is a robust detection of the prominent QRS complex, as well as other ECG signal characteristics. However, it is not clear from the literature which ECG analysis algorithms are suited for an implementation on a mobile device. We investigate current QRS detection algorithms based on three assessment criteria: 1) robustness to noise, 2) parameter choice, and 3) numerical efficiency, in order to target a universal fast-robust detector. Furthermore, existing QRS detection algorithms may provide an acceptable solution only on small segments of ECG signals, within a certain amplitude range, or amid particular types of arrhythmia and/or noise. These issues are discussed in the context of a comparison with the most conventional algorithms, followed by future recommendations for developing reliable QRS detection schemes suitable for implementation on battery-operated mobile devices.
Bus-Clamping-Based DTC: An Attempt to Reduce Harmonic Distortion and Switching Losses

This paper deals with a new direct torque control (DTC) strategy based on the bus-clamping technique dedicated to induction motor drives. The proposed strategy consists in the synthesis of two vector selection tables suitably arranged considering the bus-clamping technique. Such synthesis depends on the rotation direction of the stator flux vector. The resulting DTC strategy leads to clamp each motor phase during 60° interval in every half cycle of the reference stator flux vector. Therefore, a reduction of the inverter switching losses is gained. Furthermore, it has been found that the proposed DTC strategy offers a lower harmonic distortion of the motor phase currents and a higher capability to operate at low levels of the dc-bus voltage, which could be of interest for electric vehicle (EV) and hybrid electric vehicle (HEV) applications. These performances are confirmed by simulation and validated by experiments.
Big data analytics as-a-service: Issues and challenges

Big Data domain is one of the most promising ICT sectors with substantial expectations both on the side of market growing and design shift in the area of data storage managment and analytics. However, today, the level of complexity achieved and the lack of standardisation of Big Data management architectures represent a huge barrier towards the adoption and execution of analytics especially for those organizations and SMEs not including a sufficient amount of competences and knowledge. The full potential of Big Data Analytics (BDA) can be unleashed only through the definition of approaches that accomplish Big Data users' expectations and requirements, also when the latter are fuzzy and ambiguous. Under these premises, we propose Big Data Analytics-as-a-Service (BDAaaS) as the next-generation Big Data Analytics paradigm and we discuss issues and challenges from the BDAaaS design and development perspective.
The effect of sulphurous air pollutant exposures on symptoms, lung function, exhaled nitric oxide, and nasal epithelial lining fluid antioxidant concentrations in normal and asthmatic adults.

AIMS
To explore the effects in normal and asthmatic adults of exposure to 200 ppb sulphur dioxide (SO2) and 200 microg/m3 and 2000 microg/m3 aerosols of ammonium bisulphate (AB) and sulphuric acid (SA) (MMD 0.3 microm).


METHODS
Exposures were placebo controlled, for one hour at rest, double blind in random order. DeltaFEV1 was the primary outcome; secondary outcomes included symptoms, ventilation, exhaled nitric oxide (NO) concentrations, and nasal lavage fluid ascorbic (AA) and uric acid (UA) concentrations.


RESULTS
There were no significant changes in spirometry or symptoms with any exposure in either group. SO2 exposure was associated with an increased respiratory rate relative to air exposure in the asthmatic group (SO2: 958.9 breaths/hour; air: 906.8 breaths/hour) but the mean volume breathed did not differ significantly (SO2: 318.8 litres; air: 311.4 litres). AB exposures were associated with a significant rise in [NO] in the asthmatic (+1.51 ppb, and +1.39 ppb), but not in the normal group. Mean pre- and post-exposure [AA] tended to be higher in the normal than in the asthmatic group. Within each group, [AA] did not change significantly with any exposure. Post-exposure [UA] were greater than pre-exposure concentrations for all exposures, significantly so in the normal group for all exposures except SO2. There were no significant differences in the mean change in [UA] for any exposure relative to air.


CONCLUSIONS
The pollutant exposure concentrations employed in this study were generally much greater than ambient. It is unlikely that short lived exposures at lower concentrations would show significant effects, but effects of longer term lower concentration exposures cannot be ruled out.
Validating NEXRAD MPE and Stage III precipitation products for uniform rainfall on the Upper Guadalupe River Basin of the Texas Hill Country

r a 200 .057 .: +1 210 e@utsa.e Summary This study examines the performance of the Next Generation Weather Radar (NEXRAD) Multisensor Precipitation Estimator (MPE) and Stage III precipitation products, using a high-density rain gauge network located on the Upper Guadalupe River Basin of the Texas Hill Country. As point-area representativeness error of gauge rainfall is a major concern in assessment of radar rainfall estimation, this study develops a new method to automatically select uniform rainfall events based on coefficient of variation criterion of 3 by 3 radar cells. Only gauge observations of those uniform rainfall events are used as ground truth to evaluate radar rainfall estimation. This study proposes a new parameter probability of rain detection (POD) instead of the conditional probability of rain detection (CPOD) commonly used in previous studies to assess the capability that a radar or gauge detects rainfall. Results suggest that: (1) gauge observations of uniform rainfall better represent ground truth of a 4 · 4 km radar cell than non-uniform rainfall; (2) the MPE has higher capability of rain detection than either gauge-only or Stage III; (3) the MPE has much higher linear correlation and lower mean relative difference with gauge measurements than the Stage III does; (4) the Stage III tends to overestimate precipitation (20%), but the MPE tends to underestimate (7%). a 2007 Elsevier B.V. All rights reserved.
Greater Strength Gains after Training with Accentuated Eccentric than Traditional Isoinertial Loads in Already Strength-Trained Men

As training experience increases it becomes more challenging to induce further neuromuscular adaptation. Consequently, strength trainers seek alternative training methods in order to further increase strength and muscle mass. One method is to utilize accentuated eccentric loading, which applies a greater external load during the eccentric phase of the lift as compared to the concentric phase. Based upon this practice, the purpose of this study was to determine the effects of 10 weeks of accentuated eccentric loading vs. traditional isoinertial resistance training in strength-trained men. Young (22 ± 3 years, 177 ± 6 cm, 76 ± 10 kg, n = 28) strength-trained men (2.6 ± 2.2 years experience) were allocated to concentric-eccentric resistance training in the form of accentuated eccentric load (eccentric load = concentric load + 40%) or traditional resistance training, while the control group continued their normal unsupervised training program. Both intervention groups performed three sets of 6-RM (session 1) and three sets of 10-RM (session 2) bilateral leg press and unilateral knee extension exercises per week. Maximum force production was measured by unilateral isometric (110° knee angle) and isokinetic (concentric and eccentric 30°.s(-1)) knee extension tests, and work capacity was measured by a knee extension repetition-to-failure test. Muscle mass was assessed using panoramic ultrasonography and dual-energy x-ray absorptiometry. Surface electromyogram amplitude normalized to maximum M-wave and the twitch interpolation technique were used to examine maximal muscle activation. After training, maximum isometric torque increased significantly more in the accentuated eccentric load group than control (18 ± 10 vs. 1 ± 5%, p < 0.01), which was accompanied by an increase in voluntary activation (3.5 ± 5%, p < 0.05). Isokinetic eccentric torque increased significantly after accentuated eccentric load training only (10 ± 9%, p < 0.05), whereas concentric torque increased equally in both the accentuated eccentric load (10 ± 9%, p < 0.01) and traditional (9 ± 6%, p < 0.01) resistance training groups; however, the increase in the accentuated eccentric load group was significantly greater (p < 0.05) than control (1 ± 7%). Knee extension repetition-to-failure improved in the accentuated eccentric load group only (28%, p < 0.05). Similar increases in muscle mass occurred in both intervention groups. In summary, accentuated eccentric load training led to greater increases in maximum force production, work capacity and muscle activation, but not muscle hypertrophy, in strength-trained individuals.
Information-theoretic environmental features selection for occupancy detection in open offices

Knowing the presence or the actual number of occupants in a space at any given time is essential for the effective management of various building operation functions such as security and environmental control (e.g., lighting, HVAC). In the past, motion detection using Passive Infrared (PIR) sensors has been widely deployed in commercial buildings and can provide data on “presence” status. However, there are known limitations with PIR sensors, even for occupant presence detection, in that detection error can occur when the occupant is stationary or performing common tasks in the office space involving small movement such as typing or reading. Moreever, PIR can not detect the number of the occupants in the space. As occupants “interact” with the indoor environment, they will affect environmental conditions through the emission of CO2, heat and sound, and relatively little effort has been reported in the literature on utilizing this environmental sensing data for occupancy detection. This paper presents the findings of a study conducted at the Intelligent Workplace (IW) at Carnegie Mellon University (CMU) to address this question by exploring the most effective environmental features for occupancy level detection. A sensor network with robust, inexpensive, nonintrusive sensors such as CO2, temperature, relative humidity, and acoustics is deployed in an open-plan office space in the IW. Using information theory, the physical correlation between the number of occupants and various combinations of features extracted from sensor data from a 10 week period is studied. The results show significant correlation between features extracted from humidity, acoustics, and CO2, while little correlation with temperature data. Using features from multiple sensors increases correlation further, and over 90% information gain is acquired when at least six of the most informative features are combined. This work provides a foundation for future studies on using ambient environmental sensor data for occupancy detection.
Goal Recognition over POMDPs: Inferring the Intention of a POMDP Agent

Plan recognition is the problem of inferring the goals and plans of an agent from partial observations of her behavior. Recently, it has been shown that the problem can be formulated and solved using planners, reducing plan recognition to plan generation. In this work, we extend this model-based approach to plan recognition to the POMDP setting, where actions are stochastic and states are partially observable. The task is to infer a probability distribution over the possible goals of an agent whose behavior results from a POMDP model. The POMDP model is shared between agent and observer except for the true goal of the agent that is hidden to the observer. The observations are action sequences O that may contain gaps as some or even most of the actions done by the agent may not be observed. We show that the posterior goal distribution P (G|O) can be computed from the value function VG(b) over beliefs b generated by the POMDP planner for each possible goal G. Some extensions of the basic framework are discussed, and a number of experiments are reported.
Volatility Puzzles : A Unified Framework for Gauging Return-Volatility Regressions ∗

This paper provides a simple unified framework for assessing the empirical linkages between returns and realized and implied volatilities. First, we show that whereas the volatility feedback effect as measured by the sign of the correlation between contemporaneous return and realized volatility depends importantly on the underlying structural model parameters, the correlation between return and implied volatility is unambiguously positive for all reasonable parameter configurations. Second, the lagged return-volatility asymmetry, or the leverage effect, is always stronger for implied than realized volatility. Third, implied volatilities generally provide downward biased forecasts of subsequent realized volatilities. Our results help explain previous findings reported in the extant empirical literature, and is further corroborated by new estimation results for a sample of monthly returns and implied and realized volatilities for the aggregate S&P market index. JEL Classification: G12, C51, C22.
Probabilistic topic models

Surveying a suite of algorithms that offer a solution to managing large document archives.
The 'ABC' of MADS domain protein behaviour and interactions.

Development of eudicot flowers is under tight developmental control by genes belonging to the MADS box transcription factor family, as is nicely represented by the well-known ABC model of floral organ development. During the last two decades enormous progress has been made in our understanding of the molecular mechanisms underlying the combinatorial activity of the encoded MADS domain proteins. Here, we review how various state-of-the-art technologies were implemented in order to unravel the protein-protein interaction network for the plant MADS domain transcription factor family. In addition, results from in planta studies of MADS domain protein behaviour and interactions will be discussed. Dimerisation and higher-order complex formation of MADS domain proteins appear to be instrumental and essential for floral organ identity determination and the precise regulation of specific target gene sets. According to the current molecular model, the floral MADS proteins assemble into quaternary complexes consisting of two dimers, which is mediated by the E class proteins. Furthermore, evidence has been provided that MADS protein-protein interactions specify DNA binding capacity, inter- and intracellular localisations of the proteins and the biological function of the constituted transcription complexes.
Existential behavioural therapy for informal caregivers of palliative patients: a randomised controlled trial.

BACKGROUND
Existential behavioural therapy (EBT) was developed to support informal caregivers of palliative patients in the last stage of life and during bereavement as a manualised group psychotherapy comprising six sessions. We tested the effectiveness of EBT on mental stress and quality of life (QOL).


METHODS
Informal caregivers were randomly assigned (1:1) to EBT or a treatment-as-usual control group using computer-generated numbers in blocks of 10. Primary outcomes were assessed with the Brief Symptom Inventory (subscales somatisation, anxiety and depression), the Satisfaction with Life Scale (SWLS), the WHOQOL-BREF and a numeric rating scale for QOL (QOL-NRS, range 0-10). Data were collected at baseline, pre-treatment, post-treatment and follow-ups after 3 and 12 months. Treatment effects were assessed with a multivariate analysis of covariance.


RESULTS
Out of 160 relatives, 81 were assigned to EBT and 79 to the control group. Participants were 54.5 ± 13.2 years old; 69.9% were female. The multivariate model was significant for the pre-/post-comparison (p=0.005) and the pre-/12-month comparison (p=0.05) but not for the pre-/3-month comparison. Medium to large effects on anxiety and QOL (SWLS, WHOQOL-BREF, QOL-NRS) were found at post-treatment; medium effects on depression and QOL (QOL-NRS) emerged in the 12-month follow-up. No adverse effects of the intervention were observed.


CONCLUSION
Existential behavioural therapy appears to exert beneficial effects on distress and QOL of informal caregivers of palliative patients. Further longitudinal evidence is needed to confirm these findings.
The EVIDENT-trial: protocol and rationale of a multicenter randomized controlled trial testing the effectiveness of an online-based psychological intervention

BACKGROUND
Depressive disorders are among the leading causes of worldwide disability with mild to moderate forms of depression being particularly common. Low-intensity treatments such as online psychological treatments may be an effective way to treat mild to moderate depressive symptoms and prevent the emergence or relapse of major depression.


METHODS/DESIGN
This study is a currently recruiting multicentre parallel-groups pragmatic randomized-controlled single-blind trial. A total of 1000 participants with mild to moderate symptoms of depression from various settings including in- and outpatient services will be randomized to an online psychological treatment or care as usual (CAU). We hypothesize that the intervention will be superior to CAU in reducing depressive symptoms assessed with the Personal Health Questionnaire (PHQ-9, primary outcome measure) following the intervention (12 wks) and at follow-up (24 and 48 wks). Further outcome parameters include quality of life, use of health care resources and attitude towards online psychological treatments.


DISCUSSION
The study will yield meaningful answers to the question of whether online psychological treatment can contribute to the effective and efficient prevention and treatment of mild to moderate depression on a population level with a low barrier to entry.


TRIAL REGISTRATION



TRIAL REGISTRATION NUMBER
NCT01636752.
Software engineering training requirements in a professional services company

In the paper I characterise the nature of the business of a software engineering company such as Praxis, show how this leads to a number of problems in the planning of training, describe how we are solving these problems through, in particular, the adoption of the British Computer Society's Professional Development Scheme, and outline how training and recruitment are related.
The PreCardio-study protocol – a randomized clinical trial of a multidisciplinary electronic cardiovascular prevention programme

BACKGROUND
Cardiovascular diseases (CVD) are the leading cause of death and the third cause of disability in Europe. Prevention programmes should include interventions aimed at a reduction of medical risk factors (hypertension, hypercholesterol, hyperglycemia, overweight and obesity) as well as behavioural risk factors (sedentary lifestyle, high fat intake and low fruit and vegetable intake, smoking). The aim of this study is to investigate the effects of a multifaceted, multidisciplinary electronic prevention programme on cardiovascular risk factors.


METHODS/DESIGN
In a randomized controlled trial, one group will receive a maximal intervention (= intervention group). The intervention group will be compared to the control group receiving a minimal intervention. An inclusion of 350 patients in total, with a follow-up of 3 years is foreseen. The inclusion criteria are age between 25-65 and insured by the Onderlinge Ziekenkas, insuring for guaranteed income in case of illness for self-employed. The maximal intervention group receives several prevention consultations by their general practitioner (GP) using a new type of cardiovascular risk calculator with personalized feedback on behavioural risk factors. These patients receive a follow-up with intensive support of health behaviour change via different methods, i.e. a tailored website and personal advice of a multidisciplinary team (psychologist, physiotherapist and dietician). The aim of this strategy is to reduce cardiovascular risk factors according to the guidelines. The primary outcome measures will be cardiovascular risk factors. The secondary outcome measures are cardiovascular events, quality of life, costs and incremental cost effectiveness ratios. The control group receives prevention consultations using a new type of cardiovascular risk calculator and general feedback.


DISCUSSION
This trial incorporates interventions by GPs and other health professionals aiming at a reduction of medical and behavioural cardiovascular risk factors. An assessment of clinical, psychological and economical outcome measures will be performed.