Miracle-dz/UniFAR-FTUs huggingface dataset:
Inverse obstacle scattering problems with a single incident wave and the logarithmic differential of the indicator function in the enclosure method

This paper gives a remark on the enclosure method by considering inverse obstacle scattering problems with a single incident wave whose governing equation is given by the Helmholtz equation in two dimensions. It is concerned with the indicator function in the enclosure method. The previous indicator function is essentially real-valued since only its absolute value is used. In this paper, another method for the use of the indicator function is introduced. The method employs the logarithmic differential with respect to the independent variable of the indicator function and yields directly the coordinates of the vertices of the convex hull of unknown polygonal sound-hard obstacles or thin ones. The convergence rate of the obtained formulae is better than that of the previous indicator function. Some other applications of this method are also given.
Two-Phase Flows (Vieweg Tracts in Pure and Applied Physics)

cell, even simple structures such as the face and body-centered cubes, new considerations arise. In particular stacking faults of low energy surrounded by partial dislocations may be formed. " Heidenreich and Shockley's partial dislocations are observed by transmission electron microscopy. More than 300 pictures and photographs are illustrated to discuss detail of the Heidenreich-Shockley model. Amelinckx published a book, "The Direct Observation of Dislocations," Academic Press, 1964. Comparing the present article with his previous book, we can see an advancement of electromicroscopy technique in the past 10 years. The article further discusses the geometry (atomic arrangement), force, and energy associated with dislocations in ordered alloys and covalent structures, dislocations in layer structures and ionic crystals. J. W. Matthews, "Misfit Dislocations," pp. 461-545. If a pair of crystals with the same orientation but different lattice parameter are placed in perfect contact, the atoms near the interface adjust their position a little. This results in interfacial regions of good and bad register. The regions of bad register resemble crystal dislocations (interfacial or misfit dislocations). Many examples of misfit dislocations have been found in interfaces between face-centered cubic metal films. Misfit dislocations have also been observed in semiconducting devices on the boundary between two differently doped regions. Numerous examples of misfit dislocations have been seen at precipitates in alloys. The mathematical definition of misfit dislocations could be improved if the author employs the concept of surface dislocations used by Bullough and Bilby, Proceedings of the Physical Society, Vol. 69, Series B, 1956, p. 1276. Misfit dislocations surrounding an inclusion, for instance, can well be defined by the surface dislocations of Bullough and Bilby when Eshelby's concept of inclusion is additionally considered. The article treats observation of coherent interfaces, examples of misfit dislocations, mechanism for the generation of misfit dislocations, behavior of misfit dislocations during diffusion, and effect of misfit dislocations on interdiffusion. Quantitative tests of predictions and use of misfit strain to improve the perfection of crystals are also discussed.
Lower semicontinuity and relaxation of linear-growth integral functionals under PDE constraints

Abstract We show general lower semicontinuity and relaxation theorems for linear-growth integral functionals defined on vector measures that satisfy linear PDE side constraints (of arbitrary order). These results generalize several known lower semicontinuity and relaxation theorems for BV, BD, and for more general first-order linear PDE side constrains. Our proofs are based on recent progress in the understanding of singularities of measure solutions to linear PDEs and of the generalized convexity notions corresponding to these PDE constraints.
Numerical Investigation of Slip Effects on the Three‐Dimensional Flow Past an Impenetrable Rotating Spherical Nano Particle

The drag and lift forces acting on a rotating impenetrable spherical suspended particle in a uniform flow are numerically studied by means of three‐dimensional numerical simulation with slip boundary condition at Reynolds numbers in the range of 0.1<Re<100. The tangential shear stress is assumed to be proportional to slip velocity at the boundary. A single dimensionless parameter, the so‐called Trostel number (Tr), is defined to account for the slip at the boundary of the sphere. Increasing rotation and slip changes the flow patterns around the spherical particle. Increasing slip decreases the effects of rotation on the flow patterns around the rotating sphere. Rotation increases the drag and lift force exerted by flow at the surface of sphere but the values of drag and lift coefficients decrease by increasing slip. At full slip condition, rotation of the sphere has no significant effects on the drag coefficient values; moreover the lift coefficient of flow around the rotating spherical particle will vanish. Present numerical results at Tr=10e5 are in good agreement with other numerical results of flow around the rotating sphere at no‐slip condition.
Galaxy orbits in the Coma cluster

Le modele qui correspond le mieux aux donnees d'observation comporte une anisotropie des vitesses constante. la masse totale de l'amas est 3,5×10 15 M ○. et le rapport masse luminosite de la matiere situee a moins de 2,7 Mpc du centre est 240 (H 0 =50 km s −1 Mpc −1 )
Photodegradation and self‑healing in a Rhodamine 6G dye and Y 2 O 3 nanoparticle‑doped polyurethane random laser

One of the fundamental difficulties in implement-ing organic dyes in random lasers is irreversible photodegradation of the dye molecules, leading to loss of performance and the need to replace the dye. We report the observation of self-healing after photodegradation in a Rhodamine 6G dye and nanoparticle-doped polyurethane random laser. During irradiation, we observe two distinct temporal regions in which the random lasing emission first increases in intensity and redshifts, followed by further redshifting, spectral broadening, and decay in the emission intensity. After irradiation, the emission intensity is found to recover back to its peak value, while still being broadened and redshifted, which leads to the result of an enhancement of the spectrally integrated intensity. We also perform IR–VIS absorbance measurements and find that the results suggest that during irradiation, some of the dye molecules form dimers and trimers and that the polymer host is irreversibly damaged by photooxidation and Norrish type I photocleavage.
3 and KBeO 3 using PBE ‐ GGA and TB ‐ mBJ approach : A DFT perspective

First-principle calculations of structural, electronic and magnetic properties of perovskite NaBeO3 and KBeO3 are investigated using Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method. The structural optimization reveals that the compounds NaBeO3 and KBeO3 are stable in ferromagnetic state. The calculated formation energies confirm stability in both the perovskites. Electronic and magnetic properties are studied under GGA-PBE scheme. Further, it is improvised using TB-mBJ potential in exchange–correlation terms and delivered good results. The integer-valued total magnetic moment of 3μB in all cases signifies the half metallicity in reported compounds. The ferromagnetism predicted in both compounds is primarily due to p-orbitals of oxygen. The observed energy gaps in spins are quite larger in TB-mBJ approach and confirm half metallic ferromagnetism in compounds and hence, the compounds could be suitable for spintronic applications.
Complex Hadamard Matrices and Strongly Regular Graphs

Over forty years ago, Goethals and Seidel showed that if the adjacency algebra of a strongly regular graph $X$ contains a Hadamard matrix then $X$ is either of Latin square type or of negative Latin square type. We extend their result to complex Hadamard matrices and find only three additional families of parameters for which the strongly regular graphs have complex Hadamard matrices in their adjacency algebras. Moreover we show that there are only three distance regular covers of the complete graph that give complex Hadamard matrices.
Bound states in curved quantum waveguides

A free quantum particle living on a curved planar strip Ω of a fixed width d with Dirichlet boundary conditions is studied. It can serve as a model for electrons in thin films on a cylinder‐type substrate, or in a curved quantum wire. Assuming that the boundary of Ω is infinitely smooth and its curvature decays fast enough at infinity, it is proved that a bound state with energy below the first transversal mode exists for all sufficiently small d. A lower bound on the critical width is obtained using the Birman–Schwinger technique.
MnO 3 ( x = 0 . 0 , 0 . 1 , 0 . 2 and 0 . 3 ) manganites

The structural, transport and magnetic properties of Nd0.7−xLaxSr0.3MnO3 (for x = 0.0, 0.1, 0.2, 0.3) manganite prepared by solid-state route were investigated. All the samples are exhibiting distorted orthorhombic perovskite structure. Lattice parameters and bond angles are increasing with an increase in La concentration. The electrical resistivity ρ(T → 0) and ρ(Tc), both are decreasing with substitution of La (x = 0.0, 0.1, 0.2, 0.3) and the presence of an external magnetic field giving rise to the colossal magnetoresistance (CMR) effect. The temperature-dependent transport nature has been explored with a correlated polaron hopping mechanism based on the Holstein Hamiltonian model. This model is very well concurring with our experimental results and it is further addressing the widely known transition from the low-temperature metallic to the localized polaron hopping conductivity at high temperature. Furthermore, the spin-order temperature (Tc) and the atomic-order temperature (Tca) both are increasing with La substitution. The present analysis shows that the correlated polaron hopping model describes the transport properties of La-substituted Nd0.7−xLaxSr0.3MnO3 samples.
Measuring H-beta BLR Flows in NGC 5548

Using archival International AGN Watch observations we find a correlation between the asymmetry of the H-beta line and the system luminosity: the line becomes bluer as the system gets brighter. We also find a differential lag between the red and blue wings of the line: the blue wing lags the red by ~4 days, suggesting an inflow component of the BLR.
Critical mass for infinite-time aggregation in a chemotaxis model with indirect signal production

We study the Neumann initial-boundary problem for the chemotaxis system $$ \left\{\begin{array}{ll} u_t= \Delta u - \nabla \cdot (u\nabla v), & x\in \Omega, \, t>0, 0=\Delta v - \mu(t)+w, & x\in \Omega, \, t>0, \tau w_t + \delta w = u, & x\in \Omega, \, t>0, \end{array} \right. \qquad \qquad (\star) $$ in the unit disk $\Omega:=B_1(0)\subset \R^2$, where $\delta\ge 0$ and $\tau>0$ are given parameters and $\mu(t):=\mint_\Omega w(x,t)dx$, $t>0$. It is shown that this problem exhibits a novel type of critical mass phenomenon with regard to the formation of singularities, which drastically differs from the well-known threshold property of the classical Keller-Segel system, as obtained upon formally taking $\tau\to 0$, in that it refers to blow-up in infinite time rather than in finite time: Specifically, it is first proved that for any sufficiently regular nonnegative initial data $u_0$ and $w_0$, ($\star$) possesses a unique global classical solution. In particular, this shows that in sharp contrast to classical Keller-Segel-type systems reflecting immediate signal secretion by the cells themselves, the indirect mechanism of signal production in ($\star$) entirely rules out any occurrence of blow-up in finite time. However, within the framework of radially symmetric solutions it is next proved that whenever $\delta>0$ and $\io u_0 8\pi\delta$, one can find initial data such that $\io u_0=m$, and such that for the corresponding solution we have \bas \|u(\cdot,t)\|_{L^\infty(\Omega)} \to \infty \qquad \mbox{as} t\to\infty.
Order of magnitude time-reversible Markov chains and characterization of clustering processes

We introduce the notion of order of magnitude reversibility (OM-reversibility) in Markov chains that are parametrized by a positive parameter $\ep$. OM-reversibility is a weaker condition than reversibility, and requires only the knowledge of order of magnitude of the transition probabilities. For an irreducible, OM-reversible Markov chain on a finite state space, we prove that the stationary distribution satisfies order of magnitude detailed balance (analog of detailed balance in reversible Markov chains). The result characterizes the states with positive probability in the limit of the stationary distribution as $\ep \to 0$, which finds an important application in the case of singularly perturbed Markov chains that are reducible for $\ep=0$. We show that OM-reversibility occurs naturally in macroscopic systems, involving many interacting particles. Clustering is a common phenomenon in biological systems, in which particles or molecules aggregate at one location. We give a simple condition on the transition probabilities in an interacting particle Markov chain that characterizes clustering. We show that such clustering processes are OM-reversible, and we find explicitly the order of magnitude of the stationary distribution. Further, we show that the single pole states, in which all particles are at a single vertex, are the only states with positive probability in the limit of the stationary distribution as the rate of diffusion goes to zero.
Clebsch–Gordan and 6j-coefficients for rank 2 quantum groups

We calculate (q-deformed) Clebsch–Gordan and 6j-coefficients for rank 2 quantum groups. We explain in detail how such calculations are done, which should allow the reader to perform similar calculations in other cases. Moreover, we tabulate the q-Clebsch–Gordan and 6j-coefficients explicitly, as well as some other topological data associated with theories corresponding to rank 2 quantum groups. Finally, we collect some useful properties of the fusion rules of particular conformal field theories.
A preliminary study on public perceptions of hydrogen energy in Sarawak

Hydrogen energy technology is one of Malaysia’s efforts towards achieving the balance between economic progress and energy sustainability. Hence, the state of Sarawak has introduced The Sarawak Hydrogen Roadmap 2030 as one of its efforts as a hydrogen-based economy. While substantial investments were made at the technical aspects, it is important to understand the society’s perspectives in regards with the hydrogen energy. Hence, the aim of this study is to examine the public perception and acceptance of hydrogen energy in Sarawak. The data collection of this study was carried out via online questionnaire on 271 respondents. Statistical Package of Social Sciences (SPSS) was implemented to analyse the data collected, by using descriptive statistics, reliability test and multiple regression analysis. The study suggests that it is imperative to understand the society’s perception towards hydrogen energy in becoming one of the major key players in the industry.
A lightweight model for train bearing fault diagnosis based on multiscale attentional feature fusion

As one of the key components of a train, the running gear bearing has the highest fault rate, and its health condition is very important for the safe operation of the train. Therefore, how to quickly and accurately diagnose the health condition of the train running gear bearings under strong noise and variable working conditions has become one of the core contents of the intelligent operation and maintenance strategy. To meet these requirements, a lightweight convolutional neural network based on multiscale attentional feature fusion (MA-LCNN) is proposed in this paper, which takes the inverted residual network as the main structure. Firstly, a multiscale attention module (MA) was designed to extract fault feature information. Secondly, by embedding MAs in different locations, the ability of the MA-LCNN to extract fault feature information is greatly improved. Finally, an ablation experiment and noise resistance experiment are performed. The recognition accuracy scores of the MA-LCNN for cases 2 and 3 are 99.70% and 99.83%, respectively. The results show that the proposed attention module has better learning ability and stability compared to the contrast modules. The MA-LCNN demonstrates better fault diagnosis performance than contrast models under different noise environments and variable working conditions.
An exponential functional of random walks

The aim of this paper is to investigate discrete approximations of the exponential functional of Brownian motion (which plays an important role in Asian options of financial mathematics) with the help of simple, symmetric random walks. In some applications the discrete model could be even more natural than the continuous one. The properties of the discrete exponential functional are rather different from the continuous one: typically its distribution is singular with respect to Lebesgue measure, all of its positive integer moments are finite and they characterize the distribution. On the other hand, using suitable random walk approximations to Brownian motion, the resulting discrete exponential functionals converge almost surely to the exponential functional of Brownian motion; hence their limit distribution is the same as in the continuous case, namely that of the reciprocal of a gamma random variable, and so is absolutely continuous with respect to Lebesgue measure. In this way, we also give a new and elementary proof of an earlier result by Dufresne and Yor.
Social interaction in local public squares after dark

This paper explores social interaction in local public squares under different lighting conditions. At its best public squares are social spaces that engender a sense of belonging, increase the quality of life and wellbeing of individuals. It is proposed that outdoor lighting would be essential to the use of the public realm after dark, but empirical results regarding lighting conditions and social aspects of life in public squares are limited. Based on a socio-physical conceptual model of the transactional relationship of the user, the lit environment and the behavioural outcome, this study investigated active social interaction in daylight compared to after dark. A field study was conducted in two local public squares in Malmö, Sweden. The occurrences of which visitors were being alone, in pairs, or in groups of three or more (N=2522), and verbal or non-verbal interaction amongst those in company of another person were recorded. The lit appearance of the two squares after dark, was assessed with HDR-photography and photometric measurements; portraying dissimilar spatial, spectral and intensity characteristics. The results of social interaction show dissimilar patterns of the two squares; an increase in social interaction in EL after dark was observed in one of the squares, while a decrease in the afternoon and no significant difference was displayed in the evening after dark in the other square. It is suggested that lighting may sustain patterns of social interaction after dark, however it might be, that the company of another is especially important after dark.
Nowcasting Earthquake Occurrence in Sabah

In line with the increasing availability of seismic data, nowcasting method provides a systematic way to depict the current state of earthquake hazard within a specific geographic area. This paper implements nowcasting method to statistically assess the earthquake progression in Sabah region over the large earthquakes cycle. The analysis includes earthquake data in the state of Sabah and the surrounding regions, which is acquired from Malaysia Meteorological Department catalogue and United States Geological Survey (USGS) catalogue from year 2009 to 2018. This study discovered that EPS corresponding to M ≥ 4 events in Ranau and Lahad Datu reach about 92% and 97%, respectively. These findings indicate that both areas are in the last quarter way through their cycle to magnitude 4.0 or larger earthquakes.
A Review on Food Security Policy on Agriculture and Food in Sabah, Malaysia

Agriculture and food security are inextricably linked since agriculture is one of the sources of food security. The agriculture sector in Malaysia generates the most revenue for economic growth, apart from other sources, due to Malaysia’s vast areas of land and biodiversity. As such, the food security aims and objectives should be aligned with Malaysia’s agricultural policies, rules and regulations for economic growth and social development. This paper seeks to uncover Malaysia’s relevant and current agriculture and food security policies to identify meeting points to achieve food security goals and objectives in the future. This is also in line with the United Nations Sustainable Development Goals and in addition to maintaining the most fundamental human rights of the right to food. While there are many issues relating to agriculture, particularly concerning the advancement of science and technology, it is for the long-term benefits of food security for the population that local and indigenous people should embrace. This article adopts doctrinal method in analysing the policies by examining primary and secondary sources of laws and regulations and thus establishing common grounds for those two related areas of agriculture and food security. The findings show that while the Food Security Plan is still in the building up and perhaps future related-policies, the agriculture policies and rules and regulations should be further improved by taking an advantage of its available natural resources, only varies in line with the current commercial commodity agricultural trend, research and development. This is crucial not only to fulfil the sustainable development goals but also to improve Malaysian’s economy, standard of living, social development and their well-being. Thus, Malaysians will not go hungry due to its effective policies and rich biodiversity.
On approximation of joint fixed points

For a given partially ordered set (poset) and a given family of mappings of the poset into itself, we study the problem of the description of joint fixed points of this family. Well-known Tarski's theorem gives the structure of the set of joint fixed points of isotone automorphisms on a complete lattice. This theorem has several generalizations (see., e.g., Markowsky, Ronse) that weaken demands on the order structure and upgrade in an appropriate manner the assertion on the structure of the set of joint fixed points. However, there is a lack of the statements similar to Kantorovich or Kleene theorems, describing the set of joint fixed points in terms of convergent sequences of the operator degrees. The paper provids conditions on the poset and on the family; these conditions ensure that the iterative sequences of elements of this family approximate the set of joint fixed points. The result obtained develops in a constructive direction the mentioned theorems on joint fixed points.