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Using a unique data set of firms listed on China’s Shenzhen Stock Exchange, we show that investors’ corporate site visits convey information about future stock returns. Firms with abnormally frequent investor visits predictably outperform firms with abnormally infrequent investor visits by approximately 70-to-100 basis points per month. This return predictability concentrates on neglected firms with low trading volumes and when investors incur higher travel costs. Abnormally frequent investor visits accompany increased holdings among visiting institutions and predict improvements in firms’ fundamental performance, consistent with institutions using visits to gain an information advantage regarding underpriced firms.
The significance of conducting site visits and in-depth research by fund companies is to consistently deliver stable and substantial returns to clients through professional expertise. (Lei Jing, CEO of Harvest Fund Management Co., Ltd., China)
This paper quantifies the impacts of the airframe configuration change on the performance differences between a tube-and-wing and a blended wing body aircraft. Both are sized for a 5,000 nmi design range carrying 225 passengers, initially using the same engine. Parametric geometry is created for both concepts based on relevant public information. The tube-and-wing notional geometry is derived from the existing Boeing 767-300ER, whereas JetZero’s concept inspires the blended wing body. These geometries are optimised using computational fluid dynamics and gradient-free approaches. Drag polars for each optimised model, spanning the expected operating envelope, are generated using computational fluid dynamics simulations and multi-fidelity surrogate models. Mission analysis is performed for the blended wing body, a conventional tube-and wing variant with metallic structures, and an advanced tube-and-wing with composite structures. The results show that the blended wing body operates with 15-20% higher lift-over-drag during the cruise, 24% lower fuel burn for the design mission, and 15% reduction in ramp weight relative to the conventional tube-and-wing. These differences drop to 20% for the design mission fuel burn and 10% for the ramp weight relative to the advanced tube-and-wing. When the engines are re-sized and optimised separately for each configuration, the blended wing body demonstrates a 25% improvement in block fuel and 16% reduction in ramp weight relative to the conventional tube-and-wing, which decreases to 21% and 10% relative to the advanced tube-and-wing. In both comparisons, the fuel efficiency advantage of the blended wing body decreases as the mission range is reduced.
I argue that alienation objections to housing markets face a dilemma. Either they purport to explain distributive injustices, or they hold that markets are objectionable on intrinsic grounds. The first disjunct is empirically dubious. The second undermines the motivation for objecting to housing markets, and overgeneralizes: if markets are objectionable due to alienation, so is all large-scale social cooperation.
A combination of physics-based and data-driven post-processing techniques is proposed to extract acoustic-related shear-layer perturbation responses directly from spatio-temporally resolved schlieren video. The physics-based component uses momentum potential theory to extract the irrotational (acoustic and thermal) component from density gradients embedded in schlieren pixel intensities. For the unheated shear layer, the method filters acoustic structures and tones not evident in the raw data. The filtered data are then subjected to an efficient data-driven dynamic mode decomposition reduced-order model, which provides the forced acoustic perturbation response for broad parameter ranges. A shear layer comprising Mach 2.461 and 0.175 streams, corresponding to a convective Mach number 0.88 and containing shocks, is adopted for illustration. The overall perturbation response is first obtained using an impulse forcing in the wall-normal direction of the splitter plate, extending into subsonic and supersonic streams. Subsequently, impulse and harmonic forcings are independently applied in a pixel-by-pixel manner for a precise receptivity study. The acoustic response shows a convective wavepacket and acoustic burst from the splitter plate. The interaction with the shock and associated wave dispersion emits a second, slower, acoustic wave. Harmonic forcing indicates higher frequency-dependent sensitivity in the supersonic stream, with the most sensitive location near the outer boundary-layer region, which elicits an order of magnitude larger acoustic response compared with disturbances in the subsonic stream. Some receptive forcing regions do not generate significant acoustic waves, which may guide excitation with low noise impact.
In this paper, I argue that Johann Christoph Sturm’s eclectic scientific method reveals an unexpected indebtedness to Francis Bacon’s thought. Sturm’s reception of Bacon is particularly surprising given that the German academic context in the second half of the seventeenth century was still largely Aristotelian. Sturm is indebted to Bacon in the following respects: (1) the critique of the current state of knowledge, (2) eclecticism, (3) a fluid transition from natural history to natural philosophy, (4) the conception of science as hypothetical and dynamic and (5) experimental philosophy and the use of instruments. Given that Sturm mentions Francis Bacon in important places in his work, these respects should not easily be dismissed as commonplace. Bacon is one of Sturm’s salient sources and they are both deeply concerned with a thoroughgoing reform of existing scientific practices.
Jurassic cyrtocrinids from Spain are first documented here as representing relatively diverse assemblages from the western Tethys. The species Ascidicrinus pentagonus, Eugeniacrinites cariophilites, Gammarocrinites compressus, Pilocrinus moussoni, Sclerocrinus cf. S. strambergensis, and Tetracrinus moniliformis are described from Oxfordian marl levels belonging to the Yátova Formation, around Tosos (Zaragoza, NE Spain). Although based on partially disarticulated material, these fossils preserve cups, stem columnals, attachment structures, and brachial plates. Based on the sedimentology and associated invertebrate fauna, cyrtocrinids from this area lived below storm wave action but eventually were affected by storms, as opposed to their modern counterparts that occupy deep water environments. Some specimens preserve traces of interactions with other organisms, such as predation marks or epibiontic colonization during life and post-mortem. Attachment structures suggest cyrtocrinids mostly attached on sponges. We note that diversity of cyrtocrinids changed in step with the abundance of sponge reefs in the Jurassic, suggesting that both groups probably had an important link in that period related with similar ecological requirements.
Public acceptability is crucial for the effectiveness of policy implementation. The carbon trading market is widely adopted by many countries and regions to achieve carbon neutrality and mitigate climate change. Our paper utilizes China's carbon trading market as a quasi-natural experiment, drawing on microdata from the China Residential Energy Consumption Survey to analyze the policy's impact on public acceptance of carbon pricing. We find that the carbon trading market significantly reduces the acceptability of carbon prices among households working in carbon-related industries in the pilot areas. This conclusion is still valid after a series of robustness checks. Regarding the mechanism of influence, the carbon trading market raises households' perceived costs, mainly reflected in the negative impact of rising product prices and increasing living costs. Finally, enhancing public perception of carbon, improving the distribution effect and decreasing the information asymmetry of the policy implementation can improve public acceptability of carbon prices.
Most deaths around the world are certified, registered and then ‘coded’ for statistical purposes. Misclassified (‘hidden’) suicides are deaths assigned an ICD code that is either erroneous or that should never be specified as a cause of death. Public health strategies depend on provision of accurate mortality statistics. Suicides are under-counted, largely through misattribution to natural disease, accident, ill-defined or unknown cause (code R99) or an event of undetermined intent. Proportions of suicides misclassified to each of these codes vary between nations. It is recommended that psychological or verbal autopsies be used when investigating external deaths of uncertain cause or intention, and some R99 deaths. This applies in Britain and wherever unusual patterns of deaths could signal hidden suicides – exemplified by high rates of drug deaths in North America.
Whole-body and regional raw bioelectrical impedance analysis (BIA) parameters have been used to develop lean soft tissue estimation prediction models. Still, no regional fat mass (FM) assessment models have been provided. Hence, we aimed to develop and validate BIA-derived equations to predict regional FM against dual-energy X-ray absorptiometry (DXA) in healthy adults. One hundred and forty-eight adults (77 females) were included in this cross-sectional investigation. DXA assessed whole-body and regional FM and raw bioelectrical parameters of distinct body regions were measured using a 50 kHz phase-sensitive BIA analyser. BIA-derived equations were developed for each sex using a stepwise multiple linear regression approach in 2/3 of the sample and cross-validated in the remaining sample. The BIA-derived equations exhibited moderate to very strong relationships (P < 0·001) with DXA-measured FM of all body regions in females (r = 0·650 to 0·907) and males (r = 0·401 to 0·807). Also, for all the models, no significant deviation from linearity was found (P > 0·10). Agreement analyses revealed no associations between the differences and the means of the predicted and DXA-derived FM. However, the limits of agreement were large, with individual errors exceeding 50 % in females and 70 % in males. While the new BIA-derived equations provide a valid estimate of regional FM in middle-aged healthy adults at the population level, demonstrating a cost-effective alternative to DXA for assessing regional FM, caution is advised when applying these equations for individual-level analysis.
Insights into the paleoneurology and endocranial anatomy of ornithopod dinosaurs come largely from Northern Hemisphere taxa. The recently described non-hadrosaurid iguanodontian Fostoria dhimbangunmal from the Cenomanian of eastern Australia includes a partial skull that offers novel insights into its endocranial anatomy (i.e., the cavity housing the brain). Here, we describe the paleoneurology of F. dhimbangunmal based on a digital cranial endocast obtained from computed tomography. The endocast is mostly complete; however, it is diagenetically dorsoventrally compressed and its ventral limits are not preserved. The endocranial anatomy of F. dhimbangunmal is generally consistent with that of other non-hadrosaurid iguanodontians, including a well-developed olfactory apparatus, suggesting a good sense of smell. In contrast to hadrosaurids and some non-hadrosaurid iguanodontians, F. dhimbangunmal possesses the ancestral flexure condition, in which cranial and pontine flexure angles are subequal. The cerebrum makes up a significant portion of the endocast volume; however, the cerebral hemispheres are not as enlarged or bulbous as seen in hadrosaurids. The forebrain of F. dhimbangunmal did not fill the braincase to the same extent as in hadrosaurids. A distinct vacuity in the supraoccipital of F. dhimbangunmal may represent a new autapomorphy. This study provides the first insights into the neuroanatomy of an Australian iguanodontian dinosaur.
We conduct a theoretical analysis of the performance of $\beta $-encoders. The $\beta $-encoders are A/D (analogue-to-digital) encoders, the design of which is based on the expansion of real numbers with noninteger radix. For the practical use of such encoders, it is important to have theoretical upper bounds of their errors. We investigate the generating function of the Perron–Frobenius operator of the corresponding one-dimensional map and deduce the invariant measure of it. Using this, we derive an approximate value of the upper bound of the mean squared error of the quantization process of such encoders. We also discuss the results from a numerical viewpoint.
We study the behaviour of Kauffman bracket skein modules of 3-manifolds under gluing along surfaces. For this we extend this notion to $3$-manifolds with marking consisting of open intervals and circles in the boundary. The new module is called the stated skein module.
The first results concern non-injectivity of certain natural maps defined when forming connected sums along spheres or disks. These maps are injective for surfaces or for generic quantum parameter, but we show that in general they are not when the quantum parameter is a root of 1. We show that when the quantum parameter is a root of 1, the empty skein is zero in a connected sum where each constituent manifold has non-empty marking. We also prove various non-injectivity results for the Chebyshev-Frobenius map and the map induced by deleting marked balls.
We then interpret stated skein modules as a monoidal symmetric functor from a category of “decorated cobordisms” to a category of algebras and their bimodules. We apply this to deduce properties of stated skein modules as a Van-Kampen like theorem, a computation through Heegaard decompositions and a relation to Hochshild homology for trivial circle bundles over surfaces.
The distinction of the semantic spaces of elements and types is common practice in practically all type systems. A few type systems, including some early ones, have been proposed whose semantic space has functions only, i.e., depending on the context functions may play element roles as well as type roles. All of these systems are either lacking expressive power, in particular, polymorphism, or they violate uniqueness of types. This work presents for the first time a function-based type system in which typing is a relation between functions and which is using an ordering of functions to introduce bounded polymorphism. The ordering is based on an infinite set of top objects, itself strictly linearly ordered, each of which characterizes a certain function space. These top objects are predicative in the sense that a function using some top object cannot be smaller than this object. The interpretation of proposition as types and elements as proofs remains valid and is extended by viewing the ordering between types as logical implication. The proposed system can be shown to satisfy confluence and subject reduction. Furthermore one can show that the ordering is a partial order, every set of expressions has a maximal element, and there is a (unique) minimal, logically strongest, type among all types of an element. The latter result implies an alternative notion of uniqueness of types. Strong normalisation is the deepest property and its proof is based on a well-founded relation defined over a subsystem of expressions without eliminators. Semantic abstraction of the objects involved in typing, i.e., to use functions in element as well as type roles in a relational setting, is the major contribution of function-based type systems. This work shows that dependent products are not necessary for defining type systems with bounded polymorphism, rather it presents a consistent system with bounded polymorphism and minimal types where typing is a relation between partially ordered functions.