Flight Length Research Articles

In Case You Haven't Heard

Mental Health WeeklyVolume 28, Issue 47 p. 8-8 In Case You Haven't Heard In Case You Haven't Heard First published: 17 December 2018 https://doi.org/10.1002/mhw.31711Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract Emotional support animals will no longer be allowed on flights that are longer than eight hours, Delta Airlines announced Dec. 10. The airline said the new policy will also prevent passengers from traveling with service and support animals that are less than 4 months old, regardless of flight length, ABC News reported. Customers who purchased tickets before Dec. 18 and requested to travel with a support animal will still be allowed to travel as planned, according to the airline. The restrictions will take effect on Feb. 1, regardless of when tickets were purchased. “These updates support Delta's commitment to safety and also protect the rights of customers with documented needs — such as veterans with disabilities — to travel with trained service and support animals,” John Laughter, senior vice president of corporate safety, security and compliance, said in a statement. Delta first cracked down on its emotional support animal policy in July, stating that each customer could only travel with one animal. Volume28, Issue4717 December 2018Pages 8-8 RelatedInformation

Quasi-Ballistic Heat Conduction due to Lévy Phonon Flights in Silicon Nanowires.

Future of silicon-based microelectronics depends on solving the heat dissipation problem. A solution may lie in a nanoscale phenomenon known as ballistic heat conduction, which implies conduction of heat without heating the conductor. However, attempts to demonstrate this phenomenon experimentally are controversial and scarce, whereas its mechanism in confined nanostructures is yet to be fully understood. Here, we experimentally demonstrate quasi-ballistic heat conduction in silicon nanowires (NWs). We show that the ballisticity is the strongest in short NWs at low temperatures but weakens as the NW length or temperature is increased. Yet, even at room temperature, quasi-ballistic heat conduction remains visible in short NWs. To better understand this phenomenon, we probe directions and lengths of phonon flights. Our experiments and simulations show that the quasi-ballistic phonon transport in NWs is essentially the Lévy walk with short flights between the NW boundaries and long ballistic leaps along the NW. Thus, we conclude that ballistic heat conduction is present in silicon even at room temperature in sufficiently small nanostructures and may yet improve thermal management in silicon-based microelectronics.

Bacterial foraging optimization based on improved chemotaxis process and novel swarming strategy

Bacterial foraging optimization (BFO), a biological-inspired optimization algorithm, has been applied in various fields, such as complex function optimization, robot path planning. However, there still exist several insufficiencies in BFO algorithm due to the fixed chemotaxis step-size, the less-efficient search direction for tumbling and the swarming strategy with lower convergence rate. In order to deal with these issues, based on the Levy flight step-size and particle swarm optimization (PSO) operator, this paper proposes the improved BFO algorithm (LPBFO). To reduce the mutual interference among different dimensions, each bacterium selects one dimension for tumbling randomly during the chemotactic process in LPBFO. The step-size of each bacterium is determined by the stochastic flight lengths of the improved Levy flight which can generate small step-size with high frequency and big step-size occasionally; moreover, the stochastic step-size is also reduced adaptively based on the evolutionary generations, which makes the bacteria transform from global search to local search. Furthermore, inspired by the social information term in PSO, this paper employed the global best solution to improve the swarming performance. Several experiments on benchmark functions are carried out with the purpose of evaluating the performance of the proposed method. Experimental results show that the proposed algorithm achieves noticeable improvement compared with other competitive algorithms.

A modified crow search algorithm (MCSA) for solving economic load dispatch problem

This paper presents a novel evolutionary optimization algorithm namely the modified crow search algorithm (MCSA) for solving the non-convex economic load dispatch (ELD) problem which improves the crow search algorithm (CSA) by an innovative selection of the crows and adaptive adjustment of the flight length. MCSA is a population-based technique based on the intelligent behavior of the crows in finding food sources. In MCSA, each crow saves its food in hiding-places for the time it needs. Also, each crow searches environment to find the better foods by stealthily following other crows to discover their hiding-places. The proposed MCSA develops the search capability of crows in the original CSA and introduces a new way by which a destination is selected by a crow to follow. To indicate the applicability of MCSA in the ELD problem, it is applied on five different well-known test systems. The results are compared in terms of the solution quality, robustness, and computing time with other methods implying that the proposed method has a superior performance than the other techniques.

Unloading characteristics of flights in a flighted rotary drum operated at optimum loading

In this contribution, experimental analysis is introduced to determine the unloading characteristics of granular solid from flights. In a flighted rotary drum operated at optimum-loading. The studied unloading characteristics are: kinetic angle of repose of solid reside inside a flight, individual flight holdup, final discharge angle, cascading rate, and height and time of falling curtains. These characteristics are determined as a continuous function of the flight angular position. The tested drum is 0.5 m diameter and 0.15 m length, the rpm changes from 1 to 5, two number of flights 12 and 18, and two flight length ratios 0.375 and 0.75 are researched. Results revealed that: flights holdup is mainly influenced by flight length ratio among other studied parameters. Maximum height of falling curtains can be achieved when operating rotary drums at optimum-loading, since the bottom solid bed is no longer exists compared to over-loaded drums.

Higgsino dark matter or not: Role of disappearing track searches at the LHC and future colliders

Higgsino in supersymmetric standard models is known to be a promising candidate for dark matter in the Universe. Its phenomenological property is strongly affected by the gaugino fraction in the Higgsino-like state. If this is sizable, in other words, if gaugino masses are less than O(10) TeV, we may probe the Higgsino dark matter in future non-accelerator experiments such as dark matter direct searches and measurements of electric dipole moments. On the other hand, if gauginos are much heavier, then it is hard to search for Higgsino in these experiments. In this case, due to a lack of gaugino components, the mass difference between the neutral and charged Higgsinos is uniquely determined by electroweak interactions to be around 350 MeV, which makes the heavier charged state rather long-lived, with a decay length of about 1 cm. In this letter, we argue that a charged particle with a flight length of O(1) cm can be probed in disappearing-track searches if we require only two hits in the pixel detector. Even in this case, we can reduce background events with the help of the displaced-vertex reconstruction technique. We study the prospects of this search strategy at the LHC and future colliders for the Higgsino dark matter scenario. It is found that an almost pure Higgsino is indeed within the reach of the future 33 TeV collider experiments. We then discuss that the interplay among collider and non-accelerator experiments plays a crucial role in testing the Higgsino dark matter scenarios. Our strategy for disappearing-track searches can also enlarge the discovery potential of pure wino dark matter as well as other electroweak-charged dark matter candidates.

The relationship between time of swim start and the power of the lower limbs among young swimmers

Aim: Determining the relationship between time of swim start and the power of the lower limbs in boys and girls. Basic procedures: 32 swimmers, aged 15-16 years performed the CMJ (counter-movement jump) and the SJ (squat jump). The following were measured: jump height (H), maximal speed (vMAX) and maximal power as well as the average in absolute (respectively: P and PA) and relative terms (PREL and PAREL). Registration Recording of the start jumps to any style freestyle with the measurement of the time to cover the first 10 m of the distance was were conducted (t10). The following were determined: flight length and time (Lf, tf), height of hip joints at the time of start signal (Hh), angle in of the hip joints at the time of loss of contact with the block (AT) as well as at the time of immerging fingers in the water (AE), and the water attack angle (AA). The significance of differences between averages noted in the groups of boys and girls were evaluated and the correlations between variables were described. Main findings: The boys achieved lower t10 values and higher Lf, Hh and AT levels. In this group of subjects, only Hh negatively correlated with t10 (r=-0.57). Significant differences in the level of all variables noted for the boys and girls during the CMJ and SJ were observed. At the same time, none of the indicators characterizing CMJ were correlated with t10. In the group of boys, significant correlations were noted between t10 and H, vMAX, P, PREL, PA in SJ (-0.51≤r≤-0.72). Conclusions: There are differences between the boys and girls in performance of the start jump. One of their causes may be the disproportion in the strength of lower limb muscles. In boys, unlike girls, the SJ jump is valuable in testing the power of the lower limbs significantly correlated with the effectiveness of the start jump. The CMJ jump seems to be of low usefulness in predicting the effectiveness of a swim start.

Influence of the time interval on image-based measurement of bed-load transport

ABSTRACTThe influence of the time interval (Δt) between two successive images on measurement of bed-load dynamics has been investigated both analytically and experimentally. The analytical approach is based on simplifying bed-load motion to follow a “flight-rest” pattern. The experimental work involves measuring bed-load transport in a closed channel with a particle imaging technique. The two approaches are consistent in revealing the influence of Δt on measurement results. It is shown that an increase in Δt leads to reduction in measured particle velocity and increase in the measured number of moving particles as well as the flight time. The measured flight length and bed-load transport rate are not directly affected by Δt. The influence of Δt needs to be fully addressed in image-based measurement of bed-load transport.

The design service life of wide-body commercial aircraft research based on airlines data

To reasonably define the design service life of Chinese double aisles wide-body commercial aircraft, the exact market region and design condition are researched. The base market of Chinese double aisles wide-body commercial aircraft is China, Asia, Europe and the Pacific. In these zones, customers should be analyzed carefully, and the customers who are not available but play an important role in these zones should be picked off decisively. Besides, the flight length definition is also studied, which affects the design service life of aircraft obviously in small market region. After research, the results could reduce engineering difficulties, and also increase airlines adaptability and competitiveness in the specific market zone.

New evidences confirm that during the breeding season Lesser Kestrel is not a strictly diurnal raptor

Although Lesser Kestrel (Falco naumanni) is considered a typically diurnal species, in a previous study we have provided the first report on its nocturnal activity in Italy even in rural areaswith no artificial illumination. In this study, using new,more complete and balanced data we provide further evidences that during the breeding season LesserKestrel is not a strictly diurnal species.Using accurate GPS data-loggers on LesserKestrels belonging to the two colonies of Gravina in Puglia andAltamura (Apulia region; Southern Italy), we have registered widespread nocturnal flightswith distances from nests up to 15 km. At night, all of the surveyed Lesser Kestrels were active even in areas with no artificial illumination, and they were found in flight for about 25% of the tracking time. By comparing night-time and daytime periods, we found significant differences for three flight attributes: 1-minute flight length, distance from nest and distance from nearest roost. Instead, we found no significant differences in flight attributes betweenmales and females and between the two colonies at night.

Effect of 8 weeks of concurrent plyometric and running training on spatiotemporal and physiological variables of novice runners

Concurrent plyometric and running training has the potential to improve running economy (RE) and performance through increasing muscle strength and power, but the possible effect on spatiotemporal parameters of running has not been studied yet. The aim of this study was to compare the effect of 8 weeks of concurrent plyometric and running training on spatiotemporal parameters and physiological variables of novice runners. Twenty-five male participants were randomly assigned into two training groups; running group (RG) (n = 11) and running + plyometric group (RPG) (n = 14). Both groups performed 8 weeks of running training programme, and only the RPG performed a concurrent plyometric training programme (two sessions per week). Anthropometric, physiological (VO2max, heart rate and RE) and spatiotemporal variables (contact and flight times, step rate and length) were registered before and after the intervention. In comparison to RG, the RPG reduced step rate and increased flight times at the same running speeds (P < .05) while contact times remained constant. Significant increases in pre- and post-training (P < .05) were found in RPG for squat jump and 5 bound test, while RG remained unchanged. Peak speed, ventilatory threshold (VT) speed and respiratory compensation threshold (RCT) speed increased (P < .05) for both groups, although peak speed and VO2max increased more in the RPG than in the RG. In conclusion, concurrent plyometric and running training entails a reduction in step rate, as well as increases in VT speed, RCT speed, peak speed and VO2max. Athletes could benefit from plyometric training in order to improve their strength, which would contribute to them attaining higher running speeds.

The Implications of Intermediate Stop Operations on Aviation Emissions and Climate

Among the various transport modes aviation’s impact on climate change deserves special attention. Due to typical flight altitudes in the upper troposphere and above, the effect of aircraft engine emissions like e.g. water vapour, nitrogen oxides and aerosols on radiative forcing agents is substantial. The projected doubling of aircraft movements in the next 15 years will lead to an increase of aviation’s impact on climate and requires immediate mitigation options. Besides technological measures also new operational strategies are widely discussed; one of these concepts which has been subject of several studies in the past is Intermediate Stop Operations (ISO). It is based on the idea to reduce the stage length of flights by performing one or more intermediate landings during a mission. Here, we analyse the ISO concept by combining different models, which include a realistic traffic simulation taking into account operational constraints and ambient conditions, like e.g. wind, the calculation of engine emissions and the integration of a climate response model.We analyse the ISO concept for today’s worldwide aircraft fleet, including its influence on global emissions distributions as well as the impact on climate change by taking into account CO2 and non-CO2 effects, arising from contrail-cirrus, water vapour and nitrogen oxide emissions. We show in agreement with earlier findings that due to shorter flight distances the amount of fuel burnt over the mission can be reduced by roughly 5% on average globally. For the first time, we quantify the climate impact of ISO, where the flight trajectory is optimised for fuel use and the aircraft is not redesigned for the ISO procedure. We find an increased warming effect, which arises from nitrogen oxide and water vapour emissions, which are released at higher cruise altitudes and which over-compensate reduced warming effects from CO2 and contrail-cirrus. However, we expect a climate impact reduction for ISO even with existing aircraft, avoiding the higher flight altitude in the first flight segment and hence reducing the fuel savings. Thus, climate impact benefits could be achieved if lower fuel savings were acceptable. Moreover, this negative climate impact is found for the particular case of introducing ISO using the current wide-body fleet. It does not necessarily apply to the adoption of ISO using aircraft redesigned for a shorter range.

Understanding environment-influenced swarm behavior from a social force perspective

The relevant research on swarm behavior has focused on the facts that when individuals agree with other members in the system globally consistent behaviors are generated and that individual decisions are completely dominated by other members. In fact, when individuals generate their own behavior strategies, they tend to consider not only the influences of other members but also autonomically consider their current environment. For example, in the social foraging of flocks, the behavior strategy of each individual animal is influenced by the food distribution, and individual movement patterns are characterized by a highly efficient search strategy—Lévy walks. To investigate this, this paper proposes using an environment-driven social force perspective to explore the Lévy walks of individuals in a group in patchy food environments. This model adopts the concept of social force to quantify the social effects and the interactions between individuals and food. The coordination between forces is a key in the formation of individual behavior strategies. Our simulation results show a power-law frequency distribution for agent flight lengths that conforms to Lévy walks and verifies the hypothesis of a relationship between food density and the Lévy index. In our model, the flock still exhibits collective consistency and cohesion and yields a high value for the order parameter and population density when moving between food patches. In addition, our model explains the intraspecific cooperation and competition that occurs during foraging as proposed in related work. The simulation also validates the impact of two inducements for individual behaviors compared with several benchmark models.

Clinical predictors of outcomes in patients undergoing emergency air medical transport from Kinmen to Taiwan.

Emergency air medical transport (EAMT) is indispensable for acutely or critically ill patients in remote areas. We determined patient-level and transport-specific factors associated with all-cause mortality after EAMT.We conducted a population-based, retrospective cohort study using a prospective registry consisting of clinical/medical records. Study inclusion criteria consisted of all adults undergoing EAMT from Kinmen hospital to the ED of Taipei Veterans General Hospital (TVGH) between January 1, 2006 and December 31, 2012. The primary outcome assessments were 7-day and 30-day mortality.A total of 370 patients transported to TVGH were enrolled in the study with a mean age of 54.5 ± 21.5 (SD) years and with a male predominance (71.6%). The average in-transit time was 1.4 ± 0.4 hours. The 7-day, 30-day, and in-hospital mortality rates were 10.3%, 14.1%, and 14.9%. Among them 33.5% (124/370) were categorized under neurological etiologies, whereas 24.9% (90/370) cardiovascular, followed by 16.2% (60/370) trauma patients. Independent predictors associated with 7-day all-cause mortality were age (odds ratio [OR] 1.043, 95% confidence interval [CI] 1.016–1.070), Glasgow Coma Scale (GCS) (OR 0.730, 95% CI 0.650–0.821), and hematocrit level (OR 0.930, 95% CI 0.878–0.985). Independent predictors associated with 30-day all-cause mortality were age (OR 1.028, 95% CI 1.007–1.049), GCS (OR 0.686, 95% CI 0.600–0.785), hematocrit (OR 0.940, 95% CI 0.895–0.988), hemodynamic instability (OR 5.088 95% CI 1.769–14.635), and endotracheal intubation (OR 0.131 95% CI 0.030–0.569). The 7-day and 30-day mortality were not significantly related to transport-specific factors, such as length of flight, type of paramedic crew on board, or day and season of transport. Clinical patient-level factors, as opposed to transport-level factors, were associated with 7- and 30-day all-cause mortality in patients undergoing interfacility EAMT from Kinmen to Taiwan.

Changing measurements or changing movements? Sampling scale and movement model identifiability across generations of biologging technology.

Animal movement patterns contribute to our understanding of variation in breeding success and survival of individuals, and the implications for population dynamics. Over time, sensor technology for measuring movement patterns has improved. Although older technologies may be rendered obsolete, the existing data are still valuable, especially if new and old data can be compared to test whether a behavior has changed over time. We used simulated data to assess the ability to quantify and correctly identify patterns of seabird flight lengths under observational regimes used in successive generations of wet/dry logging technology. Care must be taken when comparing data collected at differing timescales, even when using inference procedures that incorporate the observational process, as model selection and parameter estimation may be biased. In practice, comparisons may only be valid when degrading all data to match the lowest resolution in a set. Changes in tracking technology, such as the wet/dry loggers explored here, that lead to aggregation of measurements at different temporal scales make comparisons challenging. We therefore urge ecologists to use synthetic data to assess whether accurate parameter estimation is possible for models comparing disparate data sets before planning experiments and conducting analyses such as responses to environmental changes or the assessment of management actions.

Generating Time Optimal Trajectory from Predefined 4D waypoint Networks

The main purpose of this paper is to develop a trajectory optimization method to generate optimal trajectories that minimize aircraft total trip time between the initial and final waypoint in predefined 4D waypoint networks. In this paper, the 4D waypoint networks only consist of waypoints for climb, cruise and descent approach without the take-off and landing approach phases. The time optimal trajectory is generated for three different lengths of flights (short, medium, and long-haul flight) for two different commercial aircraft and considering zero wind condition. The Results about the presented applications show that by flying a time optimal trajectory, which was found by applying a single source shortest path algorithm (Dijkstra’s algorithm), can lead to the reduction of average travel time by 2.6% with respect to the total trip time.

New mathematical models and a hybrid Grouping Evolution Strategy algorithm for optimal helicopter routing and crew pickup and delivery

Most jacket installations located in offshore regions require daily transportation of crew with helicopter, which imposes huge operational costs on oil and gas companies. In order to save on crew exchange costs, the daily flight schedule must be planned in a way that all constraints related to origin-destination itinerary, sortieing, flight length, capacity and crew member’s arrival time to the onshore base be met and the finish time of the final sortie be minimized. For this helicopter routing and crew exchange problem, two different mathematical models are developed which differ in the way the nodes and arcs are defined, and accordingly, the way the decision variables are defined. These models were solved to optimality for test problems up to 11 jackets and 28 crew members, and for the real case of South Pars Gas Field, the world's largest gas field, up to 11 jackets and 46 passengers. Considering the future extensions of the South Pars Gas Field and for problems of larger sizes, given the nature of the problem which is a grouping problem, a new algorithm, namely the hybrid Grouping Evolution Strategy (HGES), is proposed which works based on the composition of the flight sorties rather than working with each nodes in isolation. Several heuristics and a local search algorithm are incorporated in the body of GES to enhance its performance. Extensive computational experiments demonstrate that HGES can produce good solutions in an acceptable amount of time which is fit for operational use, as compared with particle swarm optimization (PSO) and pure Grouping Evolution Strategy algorithm. A GUI has also been designed to eliminate the complexity and inefficiency of the current method which is on “by-eye” basis.

Differences in Spatiotemporal Parameters Between Trained Runners and Untrained Participants.

Gómez-Molina, J, Ogueta-Alday, A, Stickley, C, Tobalina, JC, Cabrejas-Ugartondo, J, and García-López, J. Differences in spatiotemporal parameters between trained runners and untrained participants. J Strength Cond Res 31(8): 2169-2175, 2017-The aim of this study was to compare the spatiotemporal parameters of trained runners and untrained participants with the same foot strike pattern (rearfoot) during running at controlled speeds. Twenty-one participants were classified in 2 groups according to their training experience: Trained (n = 10, amateur runners with long distance training experience) and Untrained (n = 11, healthy untrained participants). Anthropometric variables were recorded, and the participants performed both a submaximal (between 9 and 15 km·h) and a graded exercise running test (from 6 km·h until exhaustion) on a treadmill. Physiological (V[Combining Dot Above]O2max, heart rate, running economy [RE], peak speed …) and biomechanical variables (contact and flight times, step rate, and length) were simultaneously registered. Trained runners showed higher step rate and shorter step length than the Untrained group at the same running speeds (between 4 and 7%, p ≤ 0.05) and at the same physiological intensities (between 7 and 11%, p ≤ 0.05). However, there were no differences in contact and flight times between groups. Significant differences (p ≤ 0.05) and large effect sizes (Cohen's d) between groups were found for body mass, sum of 6 skinfolds, V[Combining Dot Above]O2max, peak speed, and ventilatory threshold and respiratory compensation threshold speeds. The Trained group also showed a ∼7% better RE (ml·kg·km) than the Untrained group. In conclusion, adopting higher step rate and shorter step length may be an adaptive mechanism of the Trained group to reduce injury risk and possibly improve RE. However, contact and flight times were consistent regardless of training level.

An analysis of ongoing trends in airline ancillary revenues

This paper examines the performance of the two core classifications of airline ancillary revenues, which are unbundled products and commission based income. It also investigates the willingness of passengers to pay (WTP) for these services together with what type of ancillary items are acceptable at a particular price point. The study found that passengers value a narrow range of perceived ‘necessity’ products and services such as food and drink, checked baggage and seat assignment as opposed to perceived ‘optional’ unbundled or commission based products/services. It also found significant differences in WTP for specific ancillary services based on carrier type (FSC/LCC/Charter), length of flight (long and short haul) and journey purpose (business, leisure, VFR).

Analysis of preliminary design requirements of a heavy lift multirotor drone for agricultural use

Within the civil aviation cluster, the technological applications in agriculture represent a booming field consisting in acquisition of data through remote sensing and integration of sensor networks (crop status detection) or development of chemical and biological treatment applications. Drones in agriculture can be used for a variety of task, aimed to increase farm crop yields and accurately monitor fields, simultaneously decreasing time, labour and resources. While for some specific task a medium size drone can be chosen, on the other hand for other task like precision spraying of pesticide or fertilizer heavy lift drone are required. Prior to the approval of Yamaha R-MAX, an UAV helicopter which will be allowed to operate with a maximum payload of 98 kg, the Federal Aviation Administration (FAA) had only issued exemptions for much smaller drones weighing less than 55 pounds (24.98 kg). In Europe national legislations still lack of harmonization, and in Italy at the moment the local legislation restricts the possible choices to a maximum allowed take-off weight of 25kg without the necessity to submit a “permit to fly” documentation which is equivalent to the one required for a full scale commercial vehicle. Depending on the required task, one of the more important tasks of designing a multirotor Unmanned Aerial Vehicle (UAV) is the selection of a propulsion system that will provide desired performance in terms of payload and flight length or duration. Rigorous methods for selecting these drive components, that is, the motors, propellers, and batteries for electric UAVs are not readily available. A possible choice relies on using a Ready To Fly (RTF) UAV, but rapid changes in components and a fast evolution of the performance of engines and batteries allow possible updates of the existing UAV using aftermarket part to increase the flight envelope, a particularly interesting feature for heavy lift drone if a proper design method is adopted. Moreover, integration of technologies like LIDAR is easier to implement on UAV in which the design is not proprietary. In this work the technical requirements for agricultural tasks are investigated, and the state of the art of drone design method is presented, reporting an analysis of actual possibilities in terms of payload/flight envelope.