Turn Rate Research Articles

Improved square-root cubature information filter

In this paper, a theoretical comparison between existing the sigma-point information filter (SPIF) framework and the unscented information filter (UIF) framework is presented. It is shown that the SPIF framework is identical to the sigma-point Kalman filter (SPKF). However, the UIF framework is not identical to the classical SPKF due to the neglect of one-step prediction errors of measurements in the calculation of state estimation error covariance matrix. Thus SPIF framework is more reasonable as compared with UIF framework. According to the theoretical comparison, an improved cubature information filter (CIF) is derived based on the superior SPIF framework. Square-root CIF (SRCIF) is also developed to improve the numerical accuracy and stability of the proposed CIF. The proposed SRCIF is applied to a target tracking problem with large sampling interval and high turn rate, and its performance is compared with the existing SRCIF. The results show that the proposed SRCIF is more reliable and stable as compared with the existing SRCIF. Note that it is impractical for information filters in large-scale applications due to the enormous computational complexity of large-scale matrix inversion, and advanced techniques need to be further considered.

Talking Less during Social Interactions Predicts Enjoyment: A Mobile Sensing Pilot Study.

Can we predict which conversations are enjoyable without hearing the words that are spoken? A total of 36 participants used a mobile app, My Social Ties, which collected data about 473 conversations that the participants engaged in as they went about their daily lives. We tested whether conversational properties (conversation length, rate of turn taking, proportion of speaking time) and acoustical properties (volume, pitch) could predict enjoyment of a conversation. Surprisingly, people enjoyed their conversations more when they spoke a smaller proportion of the time. This pilot study demonstrates how conversational properties of social interactions can predict psychologically meaningful outcomes, such as how much a person enjoys the conversation. It also illustrates how mobile phones can provide a window into everyday social experiences and well-being.

Prediction of Methane Generation of Ozone-Treated Sludge from a Wastewater Treatment Plant

ABSTRACTPrior to anaerobic digestion of waste activated sludge (WAS), the pre-treatment of sludge including ozonation is utilized to enhance the rate of methane generation and turn it to feasible bio-resource energy. Biochemical methanogenic potential (BMP) test is a common tool to estimate the biodegradability of raw and ozonated WAS, although, it is a time consuming test requiring expensive gas analysis. The objective of this research is to recognize key parameters essential to predict biodegradability of WAS and create a valid Artificial Neural Networks (ANN) for estimating sludge biodegradability. The results reflect that ANN is an effective estimation tool.

Optimal Unemployment Insurance with Endogenous Negative Duration Dependence

This article characterizes optimal unemployment insurance (UI) in an economy with endogenous negative duration dependence in hiring rates for the unemployed. The characterization generalizes the standard Baily–Chetty result and is independent of the particular mechanism generating endogenous hiring rates. I find that at the social optimum, UI equates the moral hazard cost with the sum of the insurance benefit and a new externality correction term. The sign of this externality correction term depends, in part, on the responsiveness of hiring rates to the UI benefit. I show how the effect of UI on hiring rates in turn depends on the particular assumptions about firm behavior, considering the cases of employer screening and human capital depreciation models.

CPA Calculation Method based on AIS Position Prediction

The information on the Closest Point of Approach (CPA) of another vessel to own ship is required in a potential collision situation as it helps determines the risk to each vessel. CPA is usually calculated based on the speed and direction of the approaching ship neglecting the Change Of Speed (COS) and the Rate Of Turn (ROT). This will make the CPA less useful. To improve the CPA calculation, Automatic Identification System (AIS) information containing the Speed Over Ground (SOG), Course Over Ground (COG), COS and ROT is used. Firstly, a model using these four factors is built to predict ship positions better. Secondly, a three-step CPA searching method is developed. The developed CPA calculation method can assist in informing the navigation decisions and reducing unnecessary manoeuvres. Through the analysis of a real collision scenario, this paper shows that the proposed method can help identify and warn of anomalous ship behaviours in a realistic time frame.

Continuous Monitoring of Turning Mobility and Its Association to Falls and Cognitive Function: A Pilot Study.

Difficulty turning is a major contributor to mobility disability, falls, and reduced quality of life in older people because it requires dynamic balance control that worsens with age. However, no study has quantified the quality and quantity of turning during normal daily activities in older people. The objective of this pilot study was to determine if quality of turning during daily activities is associated with falls and/or cognitive function. Thirty-five elderly participants (85 ± 8 years) wore three Opal inertial sensors. Turning and activity rate were measured. Based on retrospective falls, participants were grouped into nonfallers (N = 16), single fallers (N = 12), and recurrent fallers (N = 7). We also determined which turning characteristic predicted falls in the 6 months following the week of monitoring. Quality of turning was significantly compromised in recurrent fallers compared with nonfallers (p < .05). In contrast, activity rate and mean number of turns per hour were similar across the three groups. Also, quality of turning during a prescribed test was similar across the three groups. Visuospatial and memory functions and the Tinetti Balance Scores were associated with quality of turning. Future falls were related to an increased variability of number of steps to turn. Continuous monitoring of turning characteristics, while walking during daily activities, is feasible in older people. Turning characteristics during daily life appear to be more sensitive to fall risk than prescribed turning tasks. These findings suggest a slower, less variable, cautious turning strategy in elderly volunteers with a history of falls.

Dynamics of sideslip perching maneuver under dynamic stall influence

This paper presents the optimization framework and aerodynamic modeling of a sideslip perching trajectory under dynamic stall influence. Based on the optimal trajectory solutions, an impact study of dynamic stall on the spatial and state trajectories of the three-dimensional (3D) perching maneuver is also discussed. At high angles of attack, the behavioral effects of the dynamic separation point on the transient post-stall region are distinguishable with rapid changes of angles of attack and aircraft's turn rates. Introduction of three internal variables thus becomes mandatory for addressing variations in flow state influenced by the swift changes in longitudinal and lateral flight angles. These variables are then integrated into a static nonlinear aerodynamic model, developed using empirical and analytical methods, and into the simulative framework as state variables. In the absence of dynamic stall effects, there is a significant discrepancy in trajectories as opposed to counterpart trajectories inclusive of this phenomenon. The consideration of dynamic stall in longitudinal frame is found to have heightened impact on perching trajectory in response to optimized control inputs as compared to that in lateral frame. With the inclusion of dynamic stall deemed necessary, a comparative study between 2D and 3D perching models is also presented to discuss the distinct drag mechanisms involved. The 3D accommodated perch utilizes the additive combination of longitudinal and lateral drag to dispense its reliance on the gravitational force. Measured against performance parameters which include metrics of spatial cost such as perching distance, longitudinal/lateral deviations and time, the study reveals the 3D mode is an improvement over the 2D mode as the latter model's intransigent characteristic of the undershoot becomes obsolete in the 3D version.

Post-Transfusion Fevers and Post-Reaction Culture Practices at a Large Academic Hospital Transfusion Service: Quality of Information and Calculated Bacterial Contamination Event Rates

Introduction: The extent to which febrile transfusion reactions (FTRs) are investigated is the extent to which bacterial contamination (BaCon) may be ascertained; FTR rates in turn vary with policies concerned with their recognition and approach. Microbiology and serology aim to rule out contamination or incompatibility, both potentially fatal. BaCon and acute hemolytic transfusion reactions (AHTR) followed transfusion related lung injury (TRALI) as the leading causes of transfusion-related death in the US in 2013 (FDA: 59 fatalities: 38% TRALI, 15% AHTR, 10% BaCon). Timely BaCon recognition enables interdiction/examination of sister products, while highlighting contamination points in the work sequence. The quality and quantity of hemovigilance data from a large hospital transfusion service were reviewed with respect to overall component utilization, adverse events, and patient/product microbiology, so as to gain a contemporary estimate of BaCon.Methods: The blood transfusion laboratory (BTL) of the tertiary care, 767-bed university hospital is supplied by Canadian Blood Services and managed by a team of technologists, a transfusion safety officer (TSO), and transfusion medicine specialists (TM MDs). Patient Reaction Events (PRE) reported to the BTL were logged over a 5 year period alongside components transfused (red cell units [pRBC], adult dose platelet concentrates [APC], frozen plasma [FP], and cryoprecipitate [crpt]). By policy, PRE are reported and formally investigated, with quarterly analyses. Roughly 3% of product recipients experience a PRE, and 40% are febrile in nature. Patient sampling is discouraged for "lower risk" fevers (asymptomatic Tmax <39C), whereas "high risk" fevers (Tmax >39C or major symptoms and/or vital sign disturbances) call for cultures of the patient and implicated product(s), as well as AHTR testing. TSO and TM MD review ensue to conclude product imputability, event severity, and final diagnosis. Definite BaCon (Def-BaCon) is defined as product and patient positive (+) for the same microbe, Probable BaCon (Prob-BaCon) as product (+) [but patient negative or untested], and Possible BaCon (Poss-BaCon) as patient (+) [but product negative or untested]. Poss-BaCon was re-classified to high-imputability (Hi-Imp Poss-BaCon) if case review failed to discover a more likely pre-existing source.Results:Between 1/1/2010 to 31/12/2014, 1,624 PRE occurred through 290,044 components dispensed (175,542 pRBC, 43,187 APC, 58,235 FP, 13,080 crpt). Patient cultures occurred in 617 (38%) of PRE, and product cultures occurred in 406 (25%) of PRE. BaCon rates varied significantly according to concluded certainty, with significant re-scaling of poss-BaCon after careful case review (Table). Table 1rate (95% confidence interval):rate per culturerate per patient reaction event (PRE)rate per component dispensedDef-BaCon (4 cases)0.65% (0.26-1.6)0.25% (0.10-0.63)1.4 x 10^-5 (0.6-3.5) or 1 in 72,511Prob-BaCon (13 cases)3.2% (1.9-5.4) (products)0.80% (0.47-1.4)4.5 x 10^-5 (2.6-7.7) or 1 in 22,311Poss-BaCon (96 cases)15.6% (12.9-18.6)5.9% (4.9-7.2)3.3 x 10^-4 (2.7-4.0) or 1 in 3,021Hi-Imp Poss-BaCon (14 cases)2.3% (1.4-3.8)0.86% (0.52-1.4)4.8 x 10^-5 (2.9-8.1) or 1 in 20,717Discussion/Conclusions: These data illustrate practical limits to deducing BaCon rates, despite robust hemovigilance. Def-BaCon was rare (1 in 72,511), while Prob-BaCon and Hi-Imp Poss-BaCon were more frequent at ~1 in 20,000. Current as-practiced tools in FTR/BaCon investigation are flawed at various levels. Underestimates stem from under-culturing and test sensitivity, and overestimates occur with incomplete case review for true sources of bacteremia, with Poss-BaCon as high as 1 in 3000. The MD Anderson Cancer Center (Ricci, et al 2014) reported on 999 reactions, with 738 (74%) in 642 central venous catheter (CVC) patients; 606 were cultured within a week of reaction, and 60 (9.9%) were bacteremic. Fevers were concluded to more likely represent the unmasking of CVC colonization rather than BaCon. Systematically incorporating (and adjusting for) CVC data may thus help to reduce inflationary poss-BaCon rates. On the other hand, more rigorous product testing (with biofilm studies) may scale BaCon rates upwards. Clinicolaboratory studies are needed to clarify the true relationship between febrile reactions, bacterial sources, and their significance. DisclosuresNo relevant conflicts of interest to declare.

Tight coordination of aerial flight maneuvers and sonar call production in insectivorous bats.

Echolocating bats face the challenge of coordinating flight kinematics with the production of echolocation signals used to guide navigation. Previous studies of bat flight have focused on kinematics of fruit and nectar-feeding bats, often in wind tunnels with limited maneuvering, and without analysis of echolocation behavior. In this study, we engaged insectivorous big brown bats in a task requiring simultaneous turning and climbing flight, and used synchronized high-speed motion-tracking cameras and audio recordings to quantify the animals' coordination of wing kinematics and echolocation. Bats varied flight speed, turn rate, climb rate and wingbeat rate as they navigated around obstacles, and they adapted their sonar signals in patterning, duration and frequency in relation to the timing of flight maneuvers. We found that bats timed the emission of sonar calls with the upstroke phase of the wingbeat cycle in straight flight, and that this relationship changed when bats turned to navigate obstacles. We also characterized the unsteadiness of climbing and turning flight, as well as the relationship between speed and kinematic parameters. Adaptations in the bats' echolocation call frequency suggest changes in beam width and sonar field of view in relation to obstacles and flight behavior. By characterizing flight and sonar behaviors in an insectivorous bat species, we find evidence of exquisitely tight coordination of sensory and motor systems for obstacle navigation and insect capture.

High manoeuvre target tracking in coordinated turns

In target tracking, most tracking algorithms are model based, and serious errors can arise when the models fail to fit the physical target motions, especially during coordinated turns. To address this problem, a two-step tracking algorithm is proposed. First, considering the diversity of the target manoeuvres, five elemental Singer models with carefully designed parameter α interact with each other in an interacting multiple model (IMM) algorithm to accomplish the tracking and estimate the target's kinematic parameters. Second, if a turn motion occurs, then it discriminates the turn motion into a horizontal turn or a three-dimensional (3D) turn; and the real-time turn rate is calculated to refine the corresponding model for tracking. Since the filtering stage is important in estimating the kinematic parameters, sparse-grid quadrature Kalman filter is employed to improve the filtering capability. The proposed algorithm is exemplified by simulation tests and data tests in 3D, and is compared with that of an IMM algorithm utilising constant velocity, constant acceleration and 3D coordinated turn models. All of the test results demonstrate that the proposed algorithm is effective and has higher accuracy.

Analysis of 3D PPN guidance laws for nonmaneuvering target

Unlike the traditional ways adopted by most of the researchers, the rotating angle of relative velocity is adopted in this work as the independent variable to analyze the analytical solution of impact angle, capture region (with or without finite line of sight (LOS) turn rate constraint), range to go, time to go, and a defined fuel cost of a traditional pure proportional navigation (PPN) guidance law for both nonmaneuvering moving, and stationary targets.

Equivalent Supply Chain Metrics. A Behavioral Perspective

We analyze how performance metrics that contain the same information affect actual decisions. We consider two such metrics from inventory management, days of supply and inventory turn rate, where one is the inverse of the other. We argue that individuals tend to assess performance based on the metrics as opposed to the fundamental attributes that actually matter and develop behavioral models that build on this effect. The models suggest that better investment decisions are made under metrics that are proportional to fundamental attributes, such as the days of supply metric. They also indicate that motivation and effort are higher under metrics that increase over-proportionally with the fundamental attribute, such as the inventory turn rate metric. In laboratory experiments, we find support for the model predictions. The results highlight the importance of including behavioral factors in metric design and provide guidance for matching metrics with managerial objectives.

Spatiotemporal regulation of Heterochromatin Protein 1-alpha oligomerization and dynamics in live cells.

Heterochromatin protein 1 (HP1) is a central factor in establishing and maintaining the heterochromatin state. As consequence of playing a structural role in heterochromatin, HP1 proteins can have both an activating as well as repressive function in gene expression. Here we probe how oligomerisation of the HP1-α isoform modulates interaction with chromatin, by spatially resolved fluorescence correlation spectroscopy (FCS). We find from fluctuation analysis of HP1-α dynamics that this isoform exists as a dimer around the periphery of heterochromatin foci and these foci locally rotate with characteristic turn rates that range from 5–100ms. From inhibition of HP1-α homo-oligomerization we find the slow turn rates (20–100 ms) are dimer dependent. From treatment with drugs that disrupt or promote chromatin compaction, we find that HP1-α dimers spatially redistribute to favor fast (5–10 ms) or slow (20–100 ms) turn rates. Collectively our results demonstrate HP1-α oligomerization is critical to the maintenance of heterochromatin and the tunable dynamics of this HP1 isoform.

Nature of Energy Index Volatility in Post Financial Crisis Period: Evidences from India

Abstract This study looks into the nexus between energy index, utility prices, and exchange rate for India, considering weekly data from June, 2008 to May, 2014. Generalized autoregressive conditional heteroskedasticity (GARCH) and exponential GARCH (EGARCH) models have been applied to scrutinize the effect of utility price and exchange rate behaviors on the energy index. The study discloses that rise in the global oil price, traded energy price and depreciation of exchange rate in turn leads to reduction of returns on energy index. It also tells that the impacts of positive and negative shocks on utility price and exchange rate volatility have symmetric consequences, and utility price and exchange rate fluctuations have enduring effect on energy index volatility.

Torsional Behavior of Axonal Microtubule Bundles

Axonal microtubule (MT) bundles crosslinked by microtubule-associated protein (MAP) tau are responsible for vital biological functions such as maintaining mechanical integrity and shape of the axon as well as facilitating axonal transport. Breaking and twisting of MTs have been previously observed in damaged undulated axons. Such breaking and twisting of MTs is suggested to cause axonal swellings that lead to axonal degeneration, which is known as “diffuse axonal injury”. In particular, overstretching and torsion of axons can potentially damage the axonal cytoskeleton. Following our previous studies on mechanical response of axonal MT bundles under uniaxial tension and compression, this work seeks to characterize the mechanical behavior of MT bundles under pure torsion as well as a combination of torsional and tensile loads using a coarse-grained computational model. In the case of pure torsion, a competition between MAP tau tensile and MT bending energies is observed. After three turns, a transition occurs in the mechanical behavior of the bundle that is characterized by its diameter shrinkage. Furthermore, crosslink spacing is shown to considerably influence the mechanical response, with larger MAP tau spacing resulting in a higher rate of turns. Therefore, MAP tau crosslinking of MT filaments protects the bundle from excessive deformation. Simultaneous application of torsion and tension on MT bundles is shown to accelerate bundle failure, compared to pure tension experiments. MAP tau proteins fail in clusters of 10–100 elements located at the discontinuities or the ends of MT filaments. This failure occurs in a stepwise fashion, implying gradual accumulation of elastic tensile energy in crosslinks followed by rupture. Failure of large groups of interconnecting MAP tau proteins leads to detachment of MT filaments from the bundle near discontinuities. This study highlights the importance of torsional loading in axonal damage after traumatic brain injury.

Collective Dynamics in the Vicsek and Vectorial Network Models Beyond Uniform Additive Noise

In this work, we analyze the coordination of interacting individuals in two nonlinear dynamical models that are subject to a new form of noise. Specifically, we propose extensions both to the classical Vicsek model, whereby each individual averages the orientation of its geographically proximal neighbors, and to the vectorial network model, in which the selection of neighbors is random and independent of the group geometric configuration. In the traditional forms of these models, the update rule for the individuals’ orientations is affected by additive uniform noise. Motivated by biological groups in which individuals’ turn rates exhibit sporadic and large changes, we extend the uniform additive noise model to a turn rate stochastic process. Through comprehensive numerical simulations, we demonstrate the impact of such occasional large deviations (intensity and frequency), along with the role of the neighbors’ selection process, on the coordination of the group. In addition, we establish a closed-form expression for the group polarization for the vectorial network model in the vicinity of an ordered state.

High angle of attack command generation technique and tracking control for agile missiles

This paper proposes a new tracking control design for agile missiles at high angle of attack regime. Firstly, mathematical descriptions of the problem are presented, taking aerodynamic uncertainties into consideration. Based on the dynamics inverse modeling in a neural network (NN) architecture, the angle of attack command augmented by a variable structure technique is then generated to correspond with the desired turn rate. Subsequently, a nonlinear adaptive control approach using sliding mode control (SMC) technique is employed to track the angle of attack command. Due to the introduction of extended state observer (ESO), the proposed approach is able to online estimate the system uncertainties and calculate derivatives of signals required for composing the control law. Finally, to demonstrate the feasibility and validity of the proposed methodology, the numerical simulation of the agile missile intercepting a target in the rear hemisphere is presented.

Evaluation of Horizontal Curve Superelevation Using Road Surface Profiler (RSP)

Riding comfortably and safely through horizontal curves in roadways should be provided by superelevation. Asphalt overlaying during the maintenance period could change superelevation (reduce or reverse it); thus, assessing a road’s cross slope along curves is of great importance. In this research, the Road Surface Profiler (RSP) device was used to measure superelevation at a curve in a newly constructed Shahroud-Miami roadway. It was chosen because of the availability of curve parameters such as start/end points, radius, superelevation, and design velocity. A good agreement was found between superelevation measured by RSP and that of the curve design. Also, it was found that rate of turn (RT) profile is a suitable tool to determine the start/end points of curves, which is a basic step in assessing curve superelevation. Three horizontal curves of Andimeshk ring were then tested by the RSP device and analyzed based on findings from the curve in Shahroud-Miami. Results show that all three curves have a superelevation shortage of approximately 3%. In these cases, the temporary solution is to install a new ＂Posted-Speed＂ sign based on existing curve superelevation

The more things change, the more they stay the same, or do they? Revisiting classroom interaction approaches and their effects on quantity and characteristics of language production

This study investigated the quantity and characteristics of student language production, discourse functions, and morphosyntactic features in three different discourse settings – face-to-face (F2F), lab-setting chatroom interactions (Lab), and any place/ any device chatroom interactions (APAD). Discourse was examined through the replication and extension of Richard Kern’s (1995) study. Similarities in findings between the two studies included a continuation of incomplete, and short sentence lengths among F2F students, an absence of F2F greetings, and a higher rate of assertions, verb tenses, and simple sentences in the Lab setting. Differences included a higher rate of F2F turns in the current study, an absence of greetings in the lab setting, and a greater number of commands among F2F participants. Findings underscored what Kern previously asserted: that F2F and chatroom settings tend to encourage and support slightly different goals associated with language discourse. Kern stated that more sophisticated conversation occurred in the chatroom setting. Current findings concurred but furthered that more conversational interaction took place within the F2F discourse setting due to a greater number of commands, turns, and incomplete sentences. Similarly, F2F students experienced greater input due to the increase of words heard, questions asked, and commands made.

The impact of odor-reward memory on chemotaxis in larval Drosophila.

How do animals adaptively integrate innate with learned behavioral tendencies? We tackle this question using chemotaxis as a paradigm. Chemotaxis in the Drosophila larva largely results from a sequence of runs and oriented turns. Thus, the larvae minimally need to determine (i) how fast to run, (ii) when to initiate a turn, and (iii) where to direct a turn. We first report how odor-source intensities modulate these decisions to bring about higher levels of chemotactic performance for higher odor-source intensities during innate chemotaxis. We then examine whether the same modulations are responsible for alterations of chemotactic performance by learned odor “valence” (understood throughout as level of attractiveness). We find that run speed (i) is neither modulated by the innate nor by the learned valence of an odor. Turn rate (ii), however, is modulated by both: the higher the innate or learned valence of the odor, the less often larvae turn whenever heading toward the odor source, and the more often they turn when heading away. Likewise, turning direction (iii) is modulated concordantly by innate and learned valence: turning is biased more strongly toward the odor source when either innate or learned valence is high. Using numerical simulations, we show that a modulation of both turn rate and of turning direction is sufficient to account for the empirically found differences in preference scores across experimental conditions. Our results suggest that innate and learned valence organize adaptive olfactory search behavior by their summed effects on turn rate and turning direction, but not on run speed. This work should aid studies into the neural mechanisms by which memory impacts specific aspects of behavior.