bluuebunny/crossref_metadata_2025_split huggingface dataset:
MixER: linear interpolation of latent space for entity resolution
Authors: Wu Huaiguang , Li Shuaichao 
Published: March 2023

AbstractEntity resolution, accurately identifying various representations of the same real-world entities, is a crucial part of data integration systems. While existing learning-based models can achieve good performance, the models are extremely dependent on the quantity and quality of training data. In this paper, the MixER model is proposed to alleviate these problems. The MixER utilizes our newly designed data augmentation method called EMix. The EMix can map discrete entity records to continuous latent space variables (e.g., probability distributions) and then linearly interpolate entity records in latent space to generate many augmented training samples. The matching model is further optimized based on the augmented data to strengthen its generalization capability. The MixER model achieves significant strengths in the data sensitivity experiments when training data is below 50. In robustness experiments, the MixER model presents an absolute performance advantage when the label noise exceeds 20%. In addition, ablation experiments demonstrate that the newly developed EMix can effectively improve the generalization ability of the matching model. The overall experimental results prove that the MixER model exhibited excellent data sensitivity and robustness over the current state-of-the-art methods.
The 3-step hedge-based valuation: fair valuation in the presence of systematic risks
Authors: Linders Daniël 
Published: March 2023

AbstractIn this paper, we introduce the 3-step hedge-based valuation for the valuation of hybrid claims. We consider an insurance portfolio which is exposed to traded risks, diversifiable risks and non-traded systematic risks. The class of 3-step hedge-based valuations is equivalent with the class of fair valuations. Closed-form solutions are derived for a portfolio of unit-linked contracts under the assumption of independence between financial and non-financial risks. We also consider the additive 3-step valuation and show that this additive valuation is a member of the more general class of 3-step hedge-based valuations.
A survey of handling and transportation of UK farmed deer
Authors: Pearce Samuel J , Foster Aiden P. , Knowles Toby G , Statham Poppy 
Published: March 2023

Abstract
Studies on the transport of deer (Cervidae), in the UK, were published > 15 years ago. A more recent study of deer transport is required to allow for assessments and improvements to the transport of farmed deer. Sixteen deer farmers participated in a survey describing their management practices related to transport. Their responses showed that most vehicles used to transport deer were designed for other livestock. Participating farmers estimated journey times to slaughter as 1–8 h, with an arithmetic mean of 4.8 (± 2.38) h. Specific concerns raised by the respondents, relating to the transport of deer, included a need for deer-specific vehicles, stop-off areas for long journeys, market locations and haulier experience. Furthermore, data were collected from two abattoirs between July 2019 and June 2020 comprising journey times, slaughter times, bruising, location of origin, vehicle type and the number of animals. In total, 4,922 deer were transported across 133 journeys (from farm to abattoir) from 61 farms. Median and range for journey length were 3.2 (0.4–9.8) h and 154.2 (7.1–462.2) km, whereas group size and time spent in the lairage were 24 (1–121) and 17.8 (10.2–68.9) h, respectively. Group size was found to be significantly associated with both the presence of bruising in a group and the amount of bruising per deer. This study provides a much-needed update on the transport of farmed deer in the UK and highlights key areas for future research including the welfare impact of transport in larger groups and for longer durations.
Strong feller and ergodic properties of the (1+1)-affine process
Authors: Chen Shukai , Li Zenghu 
Published: March 2023

AbstractWe prove some estimates for the variations of transition probabilities of the (1+1)-affine process. From these estimates we deduce the strong Feller and the ergodic properties of the total variation distance of the process. The key strategy is the pathwise construction and analysis of several Markov couplings using strong solutions of stochastic equations.
Modelling vortex flowfields by supercomputers with super-size memory
Authors: Rizzi Arthur 
Published: March 2023

SummaryPropelled by the rapid advances in VLSI technology, supercomputers are now appearing with much larger real memory capacity than previously available. These new machines are expanding our ability to formulate very large-scale discrete models in order to discover non-linear dynamical flow behaviour. With a synergetic computational-analytical view point, we can begin to explore new and unexpected flow phenomena such as wave-like instabilities of vortices and even the onset of coherent large-scale turbulence brought about by vortex stretching.
Singular perturbation theory of longitudinal dynamic stability and response of aircraft
Authors: Xu P. Y. 
Published: March 2023

SummaryThe estimation of the relative orders of the coefficients in the linear differential equations of longitudinal small perturbation of aircraft is used to analyse the classical simplified theory for the short- and long-period modes by the singular perturbation methods. The leading terms of the asymptotic expansions give the eigenvalues for short- and long-period modes with fairly good accuracy, except that the damping part of the eigenvalue for the long-period mode has relative error of the order of 10%. These approximate eigenvalues are improved by the method of strained co-ordinates which accounts for most of the differences. The dynamic response due to initial disturbances of velocity, angle of attack, and angle of pitch are also derived.
Time-delay compensation in active control algorithms
Authors: Bradshaw A. , Woodhead M. A. 
Published: March 2023

SummaryIn this paper a direct digital control law algorithm is proposed which in addition to providing tight non-interacting tracking behaviour and excellent disturbance-rejection characteristics, provides for the compensation of finite-time delays in implementation. The control-law algorithm is defined and system stability is proved in the case of multi-input multi-output linear systems. The theory is synthetic and leads directly to the determination of the appropriate controller matrices.The theory is illustrated by the presentation of simulation results in which the aircraft is represented by an analogue computer and the digital control system is implemented on a microprocessor. In the simulation study the controller is required to effect fuselage pitch pointing and vertical translation manoeuvres for the analogue computer representation of the YF-16 aircraft. It is shown that tight non-interacting control is achievable even when the control implemented is delayed by 0·1 seconds.
A stress intensity factor solution due to holes ahead of growing cracks in thin sheet material
Authors: Young J. B. , Campbell P. N. 
Published: March 2023

SummaryThe variation of the Crack Stress Intensity Factor (SIF), for two cracks growing from one hole only in an array of holes in an isotropic material under uni-axial tension has been studied. The effect of the fastener hole ahead of the growing crack was found to give an increase in the SIF only when the crack was within about one and a half diameters of the approached hole edge, compared with the level predicted by considering a single central hole in a plate. An equation suitable for inclusion in a crack growth program has been derived from the research results.
The application of mass spectrometry to the study of mixing processes in confined and unconfined gas flows
Authors: Ransom E. C. P. , Barnes J. H. 
Published: March 2023

SummaryThis paper describes a novel flow tracing technique which has been developed to obtain data on mixing and dispersion processes in gaseous flow systems. Tracer gas is injected at low flow rates into an air stream. Choice of tracer gas — primary fluid combination in relation to gas properties and detection techniques is discussed. The mode of operation of the mass spectrometer is described together with the sampling system. Analysis of samples drawn from the flow field provides tracer gas concentration profiles throughout the flow and these may be used to yield information on mixing rates. Two examples are given which illustrate the use of the method.
Transonic flow calculations around isolated inlet configurations
Authors: Peace A. J. 
Published: March 2023

SummaryA numerical method for calculating transonic flow around general inlet configurations is presented. The method is based on a finite volume potential flow algorithm with enhancements to reduce truncation errors. An approximate factorisation iterative scheme is employed and the computer code is written to take advantage of the architecture of a vector computer. The method has also been coupled with an integral boundary layer method to take into account viscous effects on the inlet surface. Results are presented for a number of configurations which are representative of current design trends, at both take-off and cruise conditions. Comparison with experimental data shows favourable agreement. The method is shown to be accurate, reliable and cheap to run.
A lock-in effect in the flow
over two cylinders
Authors: Barnes F. H. , Baxendale A. J. , Grant I. 
Published: March 2023

SummaryMeasurements are presented of the frequency of vortex shedding from two circular cylinders in a staggered arrangement. Seven different cylinders were used in turn as the upstream cylinder and the ratio of the diameter of the upstream cylinder to that of the downstream cylinder ranged from 0·00422 to 0·571. For a constant free-stream velocity changing the upstream cylinder changed the frequency of vortex shedding from the cylinder. It was found that the frequency of vortex shedding from the downstream cylinder N synchronised with that of the upstream cylinder n over a range of the latter frequency. When the frequencies were synchronised the ratio of the frequencies was given by n/N = 2. This behaviour is characteristic of a lock-in process.Lock-in was found at each of the four upstream cylinder positions tried. However, it was only when the upstream cylinder position was such that the upstream cylinder only weakly affected the flow about the downstream cylinder that lock-in was accompanied by a decrease in the base pressure. The time-mean drag force then increased with lock-in, but by a small amount only. On the other hand the fluctuating lift force increased substantially.
The effect of atmospheric turbulence on the dispersion of unguided missiles
Authors: Curcin M. , Harris R. I. 
Published: March 2023

SummaryA technique for calculating the dispersion of unguided missiles due to strong turbulent wind is presented. The three components of turbulent wind velocity are simulated along a trajectory by means of a moving average process according to Box and Jenkins. Variations of the statistics of turbulent wind with height are taken into account. A six degree of freedom program is used to calculate a trajectory. The effect of turbulent wind on both powered and unpowered flight is considered. The results of the calculation for two types of missiles are presented.
The influence of roughness trips upon boundary-layer transition Part 2. Characteristics of single spherical trips
Authors: Gibbings J. C. , Goksel O. T. , Hall D. J. 
Published: March 2023

SummaryFollowing Part 1, experimental data is given for the boundary-layer flow past single roughness trips of spherical shape. Correlations are given for the start and end of transition, for the recovery position and for the effective origin of the turbulent layer. There is evidence of a spanwise array of vortices which are found to influence both the downstream turbulent layer and the wedge growth of turbulence.
An integral method for calculating the effects on turbulent boundary-layer development of sweep and taper
Authors: Ashill P. R , Smith P. D 
Published: March 2023

SummaryA simple modification is described to the integral method of P. D. Smith for calculating turbulent boundary layers on infinite yawed wings to allow for wing planform taper. A comparison has been made between the modified and general methods for calculating three-dimensional boundary layers. This suggests that the modified method is useful for obtaining a rapid indication of the separate effects on the boundary layer of wing sweep and planform taper.
The influence of roughness trips upon boundary-layer transition. Part 1: Characteristics of wire trips
Authors: Gibbings J. C. , Goksel O. T. , Hall D. J. 
Published: March 2023

SummaryThis report gives extended data for the flow past roughness trips to provoke boundary-layer transition. This first Part reports work on wire trips giving data for the forces on the wire, the positions of recovery and effective origin of the turbulent layer, the length of the separation bubble and the beginning and end of transition. Parts 2 and 3 describe similar work on spherical roughness trips, used singly and in rows, looking in more detail at the spanwise variations in the downstream boundary-layer.
Extension of hot air balloon flight duration through adaption of balloon surface characteristics
Authors: Hallmann W. 
Published: March 2023

Two hundred years ago the first manned balloon launch was attempted. On 21st November 1783 the hot air balloon, Montgolfiere, carried two men, the adventurer Pilatre von Roxier and the Marquis D’Arlandes, nine kilometres during their twenty minute flight.The history of flight continued with many ambitious and inventive men. Among them were Graf Zeppelin, famous for airships, Otto Lilienthal for motorless flight, and the Wright brothers for the first powered flight. Since then the development went further until today large scale aircraft have become commonplace. Tomorrow, space flight could be just as common. Who dares say no to the technology that has brought us today’s living comforts?The following contribution deals with an actual problem in present day hot air balloon construction.
The influence of roughness trips upon boundary-layer transition Part 3. Characteristics of rows of spherical transition trips
Authors: Gibbings J. C. , Goksel O. T. , Hall D. J. 
Published: March 2023

SummaryFollowing Parts 1 and 2 of this experimental study the effects of rows of spherical roughness elements upon transition of the boundary layer are now described. Data presented includes that for the start of the end of transition, the effect of spacing of the roughness elements, the effective origin of the turbulent boundary layer and its development and the spanwise variations across the turbulent boundary layer.
Installation aerodynamics of ejectors in combat aircraft
Authors: Knott P. G. , Cundy D. N. 
Published: March 2023

SummaryAttention is focused on the installation aerodynamic aspects, rather than ejector design itself, of ejector augmentors installed in combat aircraft as part of the lift and propulsion system.It is indicated that in the case of the combat aircraft required to perform vertical land but not VTO, the installed thrust is such that only a small level of augmentation is required. The reason for installing an ejector is that it is capable of providing this augmentation together with a benign ground footprint. The design problems are seen to be those of relatively large volume and ensuring satisfactory aerodynamic performance in all relevant flight regimes.The installation aerodynamic problems focus on the inlet and exhaust. Performance is very sensitive to intake pressure recovery with the critical area being at the start of the landing transition. In the second case, the problem is that of providing a degree of thrust vectoring for the large low pressure exhaust to provide adequate transition performance in the face of considerable intake momentum drag.
An analytical redundancy scheme for flight control systems
Authors: McLean D. , Alkhatib K. 
Published: March 2023

SummaryThe normal practice for achieving some specified degree of reliability in automatic flight control systems has been to use methods which employ several identical feedback channels. The use of such methods requires additional sensors and other hardware components. Since such an approach has become increasingly expensive to implement, and attracts operational costs, owing to the increased weight arising from the extra equipment, any method is attractive which achieves the same degree of reliability through the use of only a single hardware path for each feedback channel. This implies the employment of special software techniques for both detecting any channel failures and reconstructing the feedback signals, which are then missing as a result of those failures. Such a scheme is presented and discussed in the paper and a number of results obtained from digital simulation are also presented to illustrate the effectiveness of the scheme for a wide variety of sensor failure conditions. The sensitivity of the scheme to initial errors in the estimation process, to the dynamic nature of the motion sensors, and to errors in the mathematical model of the aircraft dynamics, is also illustrated and discussed.
The effect of freestream turbulence on pressure fluctuations in transonic flow
Authors: Raghunathan S. , McAdam R.J.W. 
Published: March 2023

AbstractPressure fluctuation measurements were made on an 18% thick biconvex aerofoil in the region of shock boundary layer interaction at various levels of free stream flow unsteadiness. Experiments were performed with free transition and transition fixed models at a shock Mach number of 1.44 and blade chord Reynolds number of 1.6 x 105. The transition free model with a laminar boundary layer showed the presence of periodic flows at low turbulence levels which disappeared with the increase in turbulence levels. The general effect of free stream turbulence on transition fixed model is one of broad band amplification of pressure fluctuation levels in the region of shock interactions.
Derivatives and Market (Il)liquidity
Authors: Huang Shiyang , Yueshen Bart Z. , Zhang Cheng 
Published: March 2023

AbstractWe study how derivatives (with nonlinear payoffs) affect the underlying asset’s liquidity. In a rational expectations equilibrium, informed investors expect low conditional volatility and sell derivatives to the others. These derivative trades affect different investors’ utility differently, possibly amplifying liquidity risk. As investors delta hedge their derivative positions, price impact in the underlying drops, suggesting improved liquidity, because informed trading is diluted. In contrast, effects on price reversal are ambiguous, depending on investors’ relative delta hedging sensitivity (i.e., the gamma of the derivatives). The model cautions of potential disconnections between illiquidity measures and liquidity risk premium due to derivatives trading.
Epidemiological characteristics, spatial clusters and monthly incidence prediction of hand, foot and mouth disease from 2017 to 2022 in Shanxi Province, China
Authors: Ma Yifei , Xu Shujun , Dong Ali , An Jianhua , Qin Yao , Yang Hui , Yu Hongmei 
Published: March 2023

AbstractHand, foot and mouth disease (HFMD) is a common infection in the world, and its epidemics result in heavy disease burdens. Over the past decade, HFMD has been widespread among children in China, with Shanxi Province being a severely affected northern province. Located in the temperate monsoon climate, Shanxi has a GDP of over 2.5 trillion yuan. It is important to have a comprehensive understanding of the basic features of HFMD in those areas that have similar meteorological and economic backgrounds to northern China. We aimed to investigate epidemiological characteristics, identify spatial clusters and predict monthly incidence of HFMD. All reported HFMD cases were obtained from the Shanxi Center for Disease Control and Prevention. Overall HFMD incidence showed a significant downward trend from 2017 to 2020, increasing again in 2021. Children aged < 5 years were primarily affected, with a high incidence of HFMD in male patients (relative risk: 1.316). The distribution showed a seasonal trend, with major peaks in June and July and secondary peaks in October and November with the exception of 2020. Other enteroviruses were the predominant causative agents of HFMD in most years. Areas with large numbers of HFMD cases were primarily in central Shanxi, and spatial clusters in 2017 and 2018 showed a positive global spatial correlation. Local spatial autocorrelation analysis showed that hot spots and secondary hot spots were concentrated in Jinzhong and Yangquan in 2018. Based on monthly incidence from September 2021 to August 2022, the mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE) of the long short-term memory (LSTM) and seasonal autoregressive integrated moving average (SARIMA) models were 386.58vs.838.25, 2.25vs.3.08, and 461.96vs.963.13, respectively, indicating that the predictive accuracy of LSTM was better than that of SARIMA. The LSTM model may be useful in predicting monthly incidences of HFMD, which may provide early warnings of HFMD epidemics.
An Interference Model for Low Frequency Radio Spectrometer Onboard Chang’e‐4 Mission
Authors: Liu Chen‐di , Su Yan , Zhou Jian‐feng 
Published: March 2023

AbstractAs one of the critical payloads of the Chang’e‐4 mission, the low‐frequency radio spectrometer (LFRS) has yet to produce significant and influential scientific results. The main reason is that the observation data has considerable interference, mainly from the instrument platform, and presents a comb structure in the spectrum space. On this basis, combining the configuration of three antennas orthogonal to each other of the instrument, a single‐frequency interference mathematical model is proposed, solved, and evaluated in this paper. The analysis results show that the single‐frequency interference model has high fitting accuracy under a certain noise level. In the future, the interference model can be gradually extended from single‐frequency to multi‐frequency, and the actual state of instrument interference can be progressively approximated. Finally, under the requirement of a certain SNR, the interference can be accurately fitted so that the platform interference can be separated from the observation data collected by the instrument, making the effective cosmic signal stand out. In this way, the original scientific objective of the payload is expected to be achieved.