Standard Trajectory Research Articles

Vertical Displacements of the Amazon Basin From GRACE and GPS

AbstractThe extent to which Gravity Recovery and Climate Experiment (GRACE)‐recovered gravity anomalies can improve our understanding of Global Positioning System (GPS)‐measured vertical displacements is currently uncertain. To address this issue, we compared vertical displacements measured by 23 GPS stations in the Amazon basin with displacements estimated from GRACE geopotential fields. We show that despite poor correlation ( ) between rate estimates in GPS and GRACE‐derived displacement time series, further analyses reveal low bias between annual amplitude estimates and a scaling near 1. There is higher correlation ( ) between annual periodic motions, with near 1 to 1 agreement, but there is poor correlation ( ) and little agreement between semiannual amplitude estimates. Subtracting GRACE displacements from the GPS time series flattens the GPS power spectra, reducing the spectral index magnitude, on average, from (“fractional Brownian motion”) to (“fractional Gaussian noise”), suggesting that some fraction of the apparent GPS error correlation derives from mass loading signals that are not completely characterized by secular trends or seasonal periodic motions. From March 2011 to November 2016, we find a GPS and GRACE‐derived displacement combined average uplift of the Amazon basin of mm/yr and combined average annual periodic motion of mm. Deviations from a standard trajectory model for site motion are apparent in both data sets and appear to coincide with various flooding and drought events between 2011 and 2016, which suggests that the GPS coordinate time series record displacements driven by large‐scale climate oscillations.

Reference Trajectory Generation for Closed-Loop Control of Electrical Stimulation for Rehabilitation of Upper Limb

Functional movements in the paralyzed upper limb can be restored with the help of brain-computer-interface (BCI). A BCI system typically adopts a functional electrical stimulation (FES) system that activates weakened muscles that are otherwise responsible for actuating finger movements. A BCI-FES system can enable muscle contraction through the delivery of electrical stimulation pulses. The control of voltage or current stimulation parameters such as pulse width, frequency, and amplitude along with feedback signals from finger joints positions are essential for stable grasping. For the design of a closed-loop functional electrical stimulation controller, it is obligatory to set standard reference trajectories of finger joints’ angular positions and velocities for controlling stimulation parameters in neuroprosthetics and rehabilitation. This study proposes a new closed-loop control architecture targeted for achieving successful and stable grasping of an upper limb paralyzed subject. This can be achieved by characterizing each of the finger joints’ instantaneous angular position and velocity, through reference trajectories. These reference trajectories are generated corresponding to various types of grasping for feeding to the controller, responsible for stimulation of muscles. Hence, to generate such trajectories, first, grasping classification has been implemented using standard machine learning algorithms on a large set of existing real-time data of different types of objects’ grasping such as various diameter, abducted thumb and other types of objects, from many healthy subjects. The results demonstrate the successful implementation of fairly accurate classifications and trajectory generations which are crucial for closed-loop control towards stable grasping.

Morphometric analysis of the anterior column of the acetabulum and safety of intramedullary screw fixation for its fractures in Indian population: a preliminary report.

Morphometric variations of the anterior column of the acetabulum have been described in the literature for its complex structure, which can influence the safe containment of intramedullary screw for fixation of its fractures. The purpose of this CT-based study is to present a preliminary report on the morphometric variations and safety of intramedullary screw fixation of the anterior column of the acetabulum in the Indian population. CT-based data from 102 uninjured pelves were retrospectively analyzed in iPlanⓇ BrainLab AG, Feldkirchen, Germany. Narrowest zones around acetabulum and superior pubic ramus were measured. We calculated the axis of the anterior column of the acetabulum by joining the centres of these narrowest zones. Standard screws trajectories were directed along this axis. Screw length up to the first cortical perforation, the distance of the exit point from the pubic symphysis, and the length of the anterior column up to the pubic tubercle were measured. The osseous corridor of the anterior column of acetabulum had variable cross-section along its length with two constriction zones, first in the acetabular region and second in the superior pubic ramus. Only 54% of our cases allowed safe applicability of 6.5-mm-diameter screw trajectories with safety margin of 2 mm on either side of the screw. Significant morphometric and screw applicability-related differences were observed among male and female cases with males having a wider osseous corridor in general. Elimination of safety margin results in a significant increase in the screw applicability. The osseous corridor of the anterior column varies in its dimensions from individual to individual. Standard screws of 6.5-mm and 7.3-mm diameters may not be safe for intramedullary screw fixation in every patient and carry a risk of cortical violation when a 2 mm of width around the screw is considered as a safety margin. However, with a precise screw placement within the extents of the cortices of the anterior column, 6.5-mm screws can be applied in most of the female cases and 7.3-mm screws can be applied in most of the male cases for anterior column fixation.

What do patients with unmet medical needs want? A qualitative study of patients\u2019 views and experiences with expanded access to unapproved, investigational treatments in the Netherlands

BackgroundPatients with unmet medical needs sometimes resort to non-standard treatment options, including the use of unapproved, investigational drugs in the context of clinical trials, compassionate use or named-patient programs. The views and experiences of patients with unmet medical needs regarding unapproved, investigational drugs have not yet been examined empirically.MethodsIn this qualitative study, exploratory interviews and focus groups were held with patients with chronic or life-threatening diseases (n = 39), about topics related to non-standard treatment options, such as the search for non-standard treatment options, patients’ views of the moral obligations of doctors, and the conditions under which they would or would not wish to use non-standard treatment options, including expanded access to unapproved, investigational drugs.ResultsRespondents had very little knowledge about and/or experience with existing opportunities for expanded access to investigational drugs, although some respondents were actively looking for non-standard treatment options. They had high expectations of their treating physicians, assuming them to be aware of non-standard treatment options, including clinical trials elsewhere and expanded access programs, and assuming that they would inform their patients about such options. Respondents carefully weighed the risks and potential benefits of pursuing expanded access, citing concerns related to the scientific evidence of the safety and efficacy of the drug, side effects, drug-drug interactions, and the maintaining of good quality of life. Respondents stressed the importance of education and assertiveness to obtain access to good-quality health care, and were willing to pay out of pocket for investigational drugs. Patients expressed concerns about equal access to new and/or non-standard treatment options.ConclusionWhen the end of a standard treatment trajectory comes into view, patients may prefer that treating physicians discuss non-standard treatment options with them, including opportunities for expanded access to unapproved, investigational drugs. Although our respondents had varying levels of understanding of expanded access programs, they seemed capable of making well-considered choices with regard to non-standard treatment options and had realistic expectations with regard to the safety and efficacy of such options. Dutch patients might be less likely to fall prey to false hope than often presumed.

Assessing the impact of the "one-child policy" in China: A synthetic control approach.

There is great debate surrounding the demographic impact of China’s population control policies, especially the one-birth restrictions, which ended only recently. We apply an objective, data-driven method to construct the total fertility rates and population size of a ‘synthetic China’, which is assumed to be not subjected to the two major population control policies implemented in the 1970s. We find that while the earlier, less restrictive ‘later-longer-fewer’ policy introduced in 1973 played a critical role in driving down the fertility rate, the role of the ‘one-child policy’ introduced in 1979 and its descendants was much less significant. According to our model, had China continued with the less restrictive policies that were implemented in 1973 and followed a standard development trajectory, the path of fertility transition and total population growth would have been statistically very similar to the pattern observed over the past three decades.

Trajectories for Freehand-Guided Aspiration of Deep-Seated Spontaneous Intracerebral Hemorrhage

Although external landmarks and trajectories for external ventricular drainage have been described for the freehand-guided method, no standard trajectory has been reported for deep-seated intracerebral hemorrhage (ICH). This article presents a freehand-guided catheter insertion technique for deep-seated spontaneous ICH using external landmarks. Freehand-guided hematoma aspiration using Kocher's point and the external auditory canal as landmarks was performed in 32 patients with a diagnosis of spontaneous ICH in basal ganglia treated between May 2015 and July 2018 at the author's institute. In computed tomographic images, the mean actual to planned catheter tip distance was 16.1 ± 7.7 mm, the mean right-left deviation was 4.6 ± 5.2 mm, the mean anterior-posterior deviation was 11.1 ± 9.5 mm, and the mean superior-inferior deviation was 8.7 ± 4.4 mm. On largest hematoma slice, the mean distance from hematoma centers to inserted catheter was 9.8 ± 4.9 mm, and the mean horizontal and vertical distances were 4.0 ± 4.7 mm and 7.7 ± 4.8 mm, respectively. In 29 of the 32 patients, all the catheter holes contacted hematomas, whereas in the other 3 patients, 1 or more holes were in contact with brain parenchymal tissue. For patients with basal ganglia hemorrhage, freehand-guided catheter insertion and hematoma aspiration with subsequent fibrinolysis is a feasible procedure that shortens procedural times. The described technique could be used as an alternative method because it can be performed when the patient is in a critical state without additional equipment.

Piezoelectric print-head drive-waveform optimization method based on self-sensing

The piezoelectric print-head, which controls the droplet formation process by regulating the pressure wave in the tube with a voltage drive waveform, is an important device for droplet deposition. However, the structural deformation caused by the voltage-drive waveform is generally accompanied by structural vibration owing to the dynamic characteristics of the piezoelectric print-head. To precisely control the deformation of the print-head structure, this paper proposes a structural deformation control method for the piezoelectric print-head, based on self-sensing. This self-sensing principle is analyzed, and its measuring circuit is presented. A lumped-parameter model for the structural deformation of the piezoelectric print-head is established and its parameters are identified, based on self-sensing. An iterative learning control method for the structural deformation is presented, based on the identified system model. To verify the control effect of the proposed method, the radial displacement of a coaxial extruded piezoelectric print-head is controlled along a standard trapezoidal trajectory. The experimental results demonstrate that the structural deformation control precision of the piezoelectric print-head with the optimized drive waveform is considerably higher than that without the optimized drive waveform.

New type of motion trajectory for increasing the power extraction efficiency of flapping wing devices

Flapping wing devices represent a new type of renewable energy extraction technology that has the advantageous characteristics of simple structure, strong adaptability to surroundings, and little impact on the environment. This study numerically investigates the effects of vertical and elliptical airfoil trajectories on the power extraction efficiency of a flapping airfoil device using a transient numerical method based on the overset grid technique. The results are employed to propose a novel reversed-D airfoil trajectory that represents a composite of an elliptical trajectory in the first half of the motion cycle and a standard vertical trajectory in the second half of the motion cycle. The results show that for the elliptical trajectory, when the length of the half-axis in the vertical direction is fixed, the total power harvesting efficiency decreases with the increase of the horizontal half-axis length. In a certain frequency range, the decreased orders of the power extraction ability of the flapping wing are the upstream half-cycle elliptical trajectory, the vertical linear and the downstream half-cycle elliptical trajectory. Based on this understanding, we propose a new type of reversed-D motion trajectory. The power extraction efficiency of flapping wing devices operating in the reversed-D trajectory are investigated using both single and double airfoil designs. The results show that the power extraction efficiency of the single airfoil design moving along the reversed-D trajectory is greater than that obtained for the single airfoil moving along the standard vertical reciprocating trajectory within a specific range of frequency, and the increase is due mainly to an increase in the heave force. The power extraction efficiency of each airfoil in the double airfoil model moving along the reversed-D trajectory is less than that of a single airfoil moving along the vertical trajectory. However, the overall average power extraction efficiency is greater than that of a single airfoil moving along the vertical trajectory, and this increased efficiency is obtained over a larger frequency range than that of a single airfoil moving along the reversed-D trajectory. In addition, the increased efficiency of the double airfoil model is greater in the low frequency region. The proposed reversed-D trajectory facilitates the flexible arrangement of multiple airfoils in a flapping wing design. As such, the proposed reversed-D trajectory provides a promising new methodology for designing flapping wing devices with high power extraction efficiencies.

Trajectories of Growth Associated With Long-Term Stimulant Medication in the Multimodal Treatment Study of Attention-Deficit/Hyperactivity Disorder

To estimate long-term stimulant treatment associations on standardized height, weight, and body mass index trajectories from childhood to adulthood in the Multimodal Treatment Study of Attention-Deficit/Hyperactivity Disorder (MTA). Of 579 children with DSM-IV ADHD-combined type at baseline (aged 7.0-9.9 years) and 289 classmates (local normative comparison group [LNCG]), 568 and 258 respectively, were assessed 8 times over 16 years (final mean age= 24.7). Parent interview data established subgroups with self-selected Consistent (n= 53, 9%), Inconsistent (n= 374, 66%), and Negligible (n= 141, 25%) stimulant medication use, as well as patients starting stimulants prior to MTA entry (n= 211, 39%). Height and weight growth trajectories were calculated for each subgroup. Height z scores trajectories differed among subgroups (F= 2.22, p< .0001) and by stimulant use prior to study entry (F= 2.22, p< .001). The subgroup-by-assessment interaction was significant (F= 2.81, p< .0001). Paired comparisons revealed significant subgroup differences at endpoint: Consistent was shorter than Negligible (-0.66 z units /-4.06 cm /1.6 inches, t=-3.17, p< 0.0016), Consistent shorter than Inconsistent (-0.45 z units /-2.74 cm /-1.08 inches, t=-2.39, p< .0172), and the Consistent shorter than LNCG (-0.54 z units/+3.34 cm/ 1.31 inches, t=-3.30, p< 0.001). Weight z scores initially diverged among subgroups, converged in adolescence, and then diverged again in adulthood when the Consistent outweighed the LNCG (+ 3.561 z units /+7.47 kg /+16.46 lb, p< .0001). Compared with those negligibly medicated and the LNCG, 16 years of consistent stimulant treatment of children with ADHD in the MTA was associated with changes in height trajectory, a reduction in adult height, and an increase in weight and body mass index. Multimodal Treatment Study of Children With Attention Deficit and Hyperactivity Disorder (MTA); https://clinicaltrials.gov/; NCT00000388.

Diagnostic Accuracy of Adjusted Growth Curves to Predict Cognitive Scores at 24 Months in Extremely Preterm Infants (P11-054-19)

ObjectivesTo compare the diagnostic accuracy of adjusted and unadjusted growth curves to define postnatal growth and predict neurodevelopment at age 2 years in extremely preterm infants. MethodsWe performed a retrospective cohort study assessing infant growth at 36 weeks post-menstrual age (PMA) in 350 extremely preterm infants born ≤ 26 6/7 weeks gestational age (GA) between 01/01/2006-12/31/2014 at University of Alabama at Birmingham Regional Neonatal Intensive Care Unit. Postnatal growth was defined as below, within, or above target using adjusted and unadjusted growth curves. Linear regression models were used to compare adjusted and standard growth trajectories at 36 weeks PMA. The primary outcome was Cognitive Composite Score (CCS) of the Bayley Scales of Infant Development-III (Bayley-III) at 24 months. ResultsMean birthweight (BW) was 750 ± 138 g and median GA was 25 weeks (interquartile range: 24 to 26). A multivariate analysis of postnatal growth defined with adjusted curves and eight covariates (GA, BW, weight-Z-score at birth, sex, race, antenatal steroid use, singleton birth, and corrected age at follow-up assessment) predicted higher CCS-Bayley-III scores at 24 months in infants with postnatal growth within target (adjusted mean ± standard error: 89 ± 3) and lower scores in infants with postnatal growth below and above target (85 ± 3 vs. 83 ± 6, respectively) at 36 weeks PMA (P = 0.04). A multivariate analysis of postnatal growth defined with unadjusted curves and the same covariates did not predict significant differences in scores of infants with postnatal growth below (86 ± 3), within (86 ± 3), or above target (86 ± 6) at 36 weeks PMA (P = 0.99). ConclusionsAdjusted growth curves identified an inverted “U-shaped” association between postnatal growth and CCS-Bayley-III scores at 24 onths. Individualized growth trajectories adjusted for physiologic weight loss may predict cognitive impairment more accurately than traditionally defined growth standards. Additional well-powered studies are needed to validate the diagnostic ability of adjusted growth curves in routine clinical practice. Funding SourcesNone.

Comparing the Biomechanical Stability of Cortical Screw Trajectory Versus Standard Pedicle Screw Trajectory for Short- and Long-Segment Posterior Fixation in 3-Column Thoracic Spinal Injury.

Information on the performance of posterior fixation with cortical screw (CS) versus pedicle screw (PS) trajectories for stabilizing thoracolumbar burst fractures is limited. Therefore, we sought to analyze stability with CS versus PS in short- and long-segment fixations using a 3-column spinal injury model. Nondestructive flexibility tests: (1) intact, (2) intact + short fixation, (3) intact + long fixation, (4) after burst fracture, (5) short fixation + burst fracture, and (6) long fixation + burst fracture using thoracic spine segments (7 CS, 7 PS). With CS, the range of motion (ROM) was significantly greater with short-segment than with long-segment fixation in all directions, with and without burst fracture (P ≤ .008). With PS and burst fracture, ROM was significantly greater with short fixation during lateral bending and axial rotation (P < .006), but not during flexion-extension (P = .10). Groups with CS versus PS were not significantly different after burst fracture during flexion-extension and axial rotation, with short (P ≥ .58) or long fixation (P ≥ .17). During lateral bending, ROM was significantly greater with CS versus PS, without burst fracture (long fixation, P = .02) and with burst fracture (short and long fixation, P ≤ .001). CS trajectory is a valid alternative to PS trajectory for thoracic spine fixation in 3-column spinal injuries, and long-segment fixation is superior to short-segment fixation with either.

"Fragmentation as a novel measure of stability in normalized trajectories of mood and attention measured by ecological momentary assessment": Correction to Johns et al. (2019).

Reports an error in "Fragmentation as a novel measure of stability in normalized trajectories of mood and attention measured by ecological momentary assessment" by Jordan T. Johns, Junrui Di, Kathleen Merikangas, Lihong Cui, Joel Swendsen and Vadim Zipunnikov (Psychological Assessment, 2019[Mar], Vol 31[3], 329-339). The "F" at the end of the equation in the Participant-Level Normalization section should be deleted. In addition, "+OSR" should read "=OSR" in the equation in the third paragraph of the Fragmentation Measures section. (The following abstract of the original article appeared in record 2019-09637-006.) Electronic diary data, such as that acquired through Ecological Momentary Assessments (EMA), has historically provided novel insights into diverse psychological processes. Analyses of these data typically focus on modeling participant-specific means, variability, and stability. We propose a novel statistical framework to determine participant stability by quantifying fragmentation of standardized trajectories using the following 2-step approach: (1) participant-level EMA scores are normalized, and (2) normalized scores are dichotomized into 2 states, inside and outside a range of 1 standard deviation. Within-participant fragmentation measures were calculated from dichotomized scores and modeled with various covariates. We used this method to study patterns of emotional states and showed that the proposed fragmentation measures differentiate mood disorder subtypes, including Bipolar I (BPI), Bipolar II, and major depressive disorder (MDD) compared with unaffected controls. Fragmentation measures were regressed on the mood disorder subtype, adjusting for age, sex, body mass index, and mean squared successive difference. The analyses revealed decreased stability (more fragmentation) among those with BPI when inside the participant-specific standard range of attention (β = 0.09, p = .004) and decreased stability among those with MDD inside the standard range of mood (β = 0.04, p = .039) and attention (β = 0.05, p = .017). This work provides an illustration of the clinical significance of EMA in characterizing the stability of mood, attention, or other psychological states that may underlie psychological disorders and phenomena. The application of fragmentation provides a novel statistical approach that can characterize within-participant stability beyond currently available traditional approaches. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Sideways and stable crack propagation in a silicone elastomer

We have discovered a peculiar form of fracture that occurs in a highly stretchable silicone elastomer (Smooth-On Ecoflex 00-30). Under certain conditions, cracks propagate in a direction perpendicular to the initial precut and in the direction of the applied load. In other words, the crack deviates from the standard trajectory and instead propagates perpendicular to that trajectory. The crack arrests stably, and thus the material ahead of the crack front continues to sustain load, thereby enabling enormous stretchabilities. We call this phenomenon "sideways" and stable cracking. To explain this behavior, we first perform finite-element simulations that demonstrate a propensity for sideways cracking, even in an isotropic material. The simulations also highlight the importance of crack-tip blunting on the formation of sideways cracks. Next, we provide a hypothesis on the origin of sideways cracking that relates to microstructural anisotropy (in a nominally isotropic elastomer). To substantiate this hypothesis, we transversely prestretch samples to various extents before fracture testing, as to determine the influence of microstructural arrangement (chain alignment and strain-induced crystallization) on fracture energy. We also perform microstructural characterization that indicates that significant chain alignment and strain-induced crystallization indeed occur in this material upon stretching. We conclude by characterizing how a number of loading conditions, such as sample geometry and strain rate, affect this phenomenon. Overall, this paper provides fundamental mechanical insight into basic phenomena associated with fracture of elastomers.

PHEV powertrain co-design with vehicle performance considerations using MDSDO

The complexity of plug-in hybrid-electric vehicles (PHEVs) motivates the simultaneous integration of component design and supervisory control strategy decisions. Methods from combined optimal design and control (co-design) are generally used to manage such integrated system design decisions. Although several studies have investigated the PHEV powertrain co-design problem, the impact of key vehicle performance criteria such as 0–60 mph acceleration time and all-electric-range (AER) has rarely been explicitly included in such system co-design problems. This is problematic as these vehicle performance criteria strongly affect component sizing and control strategy in a way that a non-performance-based co-design solution could become sub-optimal. Therefore, this study addresses this issue by formulating and solving a PHEV powertrain co-design problem that explicitly includes vehicle-level performance constraints. In particular, a three-phase, PHEV powertrain co-design problem is solved to simultaneously identify the optimal supervisory control strategies during the acceleration performance and standard duty cycle phases, along with the optimal component designs spanning all phases (acceleration performance, standard duty cycle, and AER performance) such that the vehicle powertrain cost is minimized. A relatively new, balanced co-design approach known as multidisciplinary dynamic system design optimization (MDSDO) is used to solve the problem. The optimal design and standard duty cycle supervisory control trajectories are compared to the solution of a non-performance-based co-design problem. The results indicate that the formal inclusion of vehicle performance criteria in a co-design problem significantly affects component design and supervisory control strategies.

Re-entry guidance method based on decoupling control variables and waypoint

ABSTRACTGenerally, earth rotating and non-spherical perturbation of the earth in re-entry motion model are simplified using the standard trajectory guidance method. The re-entry motion is also simplified to horizontal motion and vertical motion and controlled, respectively. The simplification of re-entry motion model will lead to loss of motion accuracy and location accuracy. The direct decomposition will lead to the reduction of control accuracy because the horizontal motion and the vertical motion are coupled in re-entry. To improve the standard trajectory guidance method, the standard trajectory guidance method based on decoupling control variables and waypoint is proposed in this paper. The proposed guidance method will not simplify earth rotating and non-spherical perturbation of the earth in motion equation or decompose the re-entry motion to horizontal motion and vertical motion. Trajectory waypoint is adopted to reduce the change frequency of tracking states, because tracking states change frequently if the entire standard trajectory is tracked in real time.

Concurrent Validity of Field-Based Diagnostic Technology Monitoring Movement Velocity in Powerlifting Exercises.

Mitter, B, Hölbling, D, Bauer, P, Stöckl, M, Baca, A, and Tschan, H. Concurrent validity of field-based diagnostic technology monitoring movement velocity in powerlifting exercises. J Strength Cond Res 35(8): 2170-2178, 2021-The study was designed to investigate the validity of different technologies used to determine movement velocity in resistance training. Twenty-four experienced powerlifters (18 male and 6 female; age, 25.1 ± 5.1 years) completed a progressive loading test in the squat, bench press, and conventional deadlift until reaching their 1 repetition maximum. Peak and mean velocity were simultaneously recorded with 4 field-based systems: GymAware (GA), FitroDyne (FD), PUSH (PU), and Beast Sensor (BS). 3D motion capturing was used to calculate specific gold standard trajectory references for each device. GA provided the most accurate output across exercises (r = 0.99-1, ES = -0.05 to 0.1). FD showed similar results for peak velocity (r = 1, standardized mean bias [ES] = -0.1 to -0.02) but considerably less validity for mean velocity (r = 0.92-0.95, ES = -0.57 to -0.29). Reasonably valid to highly valid output was provided by PU in all exercises (r = 0.91-0.97, ES = -0.5 to 0.28) and by BS in the bench press and for mean velocity in the squat (r = 0.87-0.96, ES = -0.5 to -0.06). However, BS did not reach the thresholds for reasonable validity in the deadlift and for peak velocity in the squat, mostly due to high standardized mean bias (ES = -0.78 to -0.63). In conclusion, different technologies should not be used interchangeably. Practitioners who require negligible measurement error in their assessment of movement velocity are advised to use linear position transducers over inertial sensors.

Many-body contacts in fractal polymer chains and fractional Brownian trajectories.

We calculate the probabilities that a trajectory of a fractional Brownian motion with arbitrary fractal dimension d_{f} visits the same spot n≥3 times, at given moments t_{1},...,t_{n}, and obtain a determinant expression for these probabilities in terms of a displacement-displacement covariance matrix. Except for the standard Brownian trajectories with d_{f}=2, the resulting many-body contact probabilities cannot be factorized into a product of single-loop contributions. Within a Gaussian network model of a self-interacting polymer chain, which we suggested recently [K. Polovnikov et al., Soft Matter 14, 6561 (2018)1744-683X10.1039/C8SM00785C], the probabilities we calculate here can be interpreted as probabilities of multibody contacts in a fractal polymer conformation with the same fractal dimension d_{f}. This Gaussian approach, which implies a mapping from fractional Brownian motion trajectories to polymer conformations, can be used as a semiquantitative model of polymer chains in topologically stabilized conformations, e.g., in melts of unconcatenated rings or in the chromatin fiber, which is the material medium containing genetic information. The model presented here can be used, therefore, as a benchmark for interpretation of the data of many-body contacts in genomes, which we expect to be available soon in, e.g., Hi-C experiments.

Fragmentation as a novel measure of stability in normalized trajectories of mood and attention measured by ecological momentary assessment.

Electronic diary data, such as that acquired through Ecological Momentary Assessments (EMA), has historically provided novel insights into diverse psychological processes. Analyses of these data typically focus on modeling participant-specific means, variability, and stability. We propose a novel statistical framework to determine participant stability by quantifying fragmentation of standardized trajectories using the following 2-step approach: (1) participant-level EMA scores are normalized, and (2) normalized scores are dichotomized into 2 states, inside and outside a range of 1 standard deviation. Within-participant fragmentation measures were calculated from dichotomized scores and modeled with various covariates. We used this method to study patterns of emotional states and showed that the proposed fragmentation measures differentiate mood disorder subtypes, including Bipolar I (BPI), Bipolar II, and major depressive disorder (MDD) compared with unaffected controls. Fragmentation measures were regressed on the mood disorder subtype, adjusting for age, sex, body mass index, and mean squared successive difference. The analyses revealed decreased stability (more fragmentation) among those with BPI when inside the participant-specific standard range of attention (β = 0.09, p = .004) and decreased stability among those with MDD inside the standard range of mood (β = 0.04, p = .039) and attention (β = 0.05, p = .017). This work provides an illustration of the clinical significance of EMA in characterizing the stability of mood, attention, or other psychological states that may underlie psychological disorders and phenomena. The application of fragmentation provides a novel statistical approach that can characterize within-participant stability beyond currently available traditional approaches. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Circular design: reused materials and the future reuse of building elements in architecture. Process, challenges and case studies

The design process in which existing materials are reused or which aims to enable future reuse of building elements differs significantly from a standard design trajectory. Working with construction waste requires material tests, assessments, and consultations as well as defining available waste sources. Designing for future reuse demands extended research on the layers of buildings, properties of materials, dismountable joints, maintenance techniques, and reuse scenarios. This results in a longer introductory phase and often in a higher cost of the project. Circular design also faces other challenges, which concern environmental (e.g., recycling potential), social (e.g., social perception of reused materials), infrastructural (e.g., lack of processing plants) and legal issues (e.g., non-flexible construction law). These aspects often influence already technically complicated design process. However, there are projects in which reused materials were successfully implemented. Buildings designed for future reuse of their elements are also being built. In this paper selected case studies from Germany, the Netherlands, Poland and Denmark present how different types of construction waste (incl. waste from concrete, brick, wooden, metal, plastic and glass elements) can be reused in architecture. Moreover, this article analyses the circular design process, related challenges and investigates the emerging role of the architect.

Improved Tentacle-Based Guidance for Reentry Gliding Hypersonic Vehicle With No-Fly Zone Constraint

An improved tentacle-based bank-angle transient method that requires less computation and provides effective feedback is proposed to offer a new choice for reentry gliding hypersonic vehicle maneuvering guidance. The longitudinal guidance strategy of hypersonic vehicles is applied to track standard trajectories, and the improved tentacle-based bank angle transient lateral strategy avoids static or dynamic no-fly zones. The proposed lateral strategy generates three tentacles for detection, addresses numerical heading angle limitations or no-fly zone constraints, and provides control commands through a time-counting filter. Dispersed cases are verified for static no-fly zones, and a warning area is proposed to avoid dynamic no-fly zones. For dynamic no-fly zones, the velocity and initial position of the no-fly zone are discussed in terms of the impact on the guidance. Finally, the guidance strategy is tested on a high-performance Common Aero Vehicle model in many flights, and all results for the constraints and computation time indicate that the improved tentacle-based guidance method is effective for avoiding no-fly zones where some information is unknown.