A New Active Contour Medical Image Segmentation Method Based on Fractional Varying-Order Differential

Image segmentation technology is dedicated to the segmentation of intensity inhomogeneous at present. In this paper, we propose a new method that incorporates fractional varying-order differential and local fitting energy to construct a new variational level set active contour model. The energy functions in this paper mainly include three parts: the local term, the regular term and the penalty term. The local term combined with fractional varying-order differential can obtain more details of the image. The regular term is used to regularize the image contour length. The penalty term is used to keep the evolution curve smooth. True positive (TP) rate, false positive (FP) rate, precision (P) rate, Jaccard similarity coefficient (JSC), and Dice similarity coefficient (DSC) are employed as the comparative measures for the segmentation results. Experimental results for both synthetic and real images show that our method has more accurate segmentation results than other models, and it is robust to intensity inhomogeneous or noises.

Modelling the nucleation and propagation of cracks at twin boundaries

Fracture arising from cracks nucleating and propagating along twin boundaries is commonly observed in metals that exhibit twinning as a plastic deformation mechanism. This phenomenon affects the failure of macroscopic mechanical components, but it is not fully understood. We present simulations in which a continuum model for discrete twins and a cohesive zone model are coupled to aid the understanding of fracture at twin boundaries. The interaction between different twin systems is modelled using a local term that depends on the continuum twin variables. Simulations reveal that the resolved shear stress necessary for an incident twin to propagate through a barrier twin can be up to eight times the resolved shear stress for twin nucleation. Interface elements are used at the interfaces between all bulk elements to simulate arbitrary intragranular cracks. An algorithm to detect twin interfaces is developed and their strength has been calibrated to give good agreement with the experimentally observed fracture path. The elasto-plastic deformation induced by discrete twins is modelled using the crystal plasticity finite element method and the stress induced by twin tips is captured. The tensile stress caused by the tip of an incident twin on a barrier twin is sufficient to nucleate a crack. A typical staircase fracture path, with cracks propagating along the twin interfaces, is reproduced only if the strength of the twin interfaces is decreased to about one-third of the strength of the bulk material. This model can be used to help understand fracture caused by the activation of multiple twin systems in different materials.

The debate concerning the origin of the Whin Sill of northeast England during the early and mid-19th century

The term sill nowadays employed for a broadly concordant igneous intrusion is widely believed to have been derived from the local term for persistent hard beds in the Carboniferous sequence of Northeast England, in particular the Whin Sill. Despite the intrusive origin of the Whin having been demonstrated in Teesdale by Sedgwick in 1827, for much of the 19th Century the alternative extrusive hypothesis, of which Phillips (1836) was the principal proponent, was widely favoured. There were three principal reasons why the intrusive origin was not more widely held, unquestioning acceptance of the erroneous belief of local miners that the Whin Sill was always at the same stratigraphical horizon, a perception that the Teesdale outcrops were not necessarily typical of the rest of the region and a reluctance to accept that the intrusion of such large volumes of magma over such a great area was physically possible. In the 1870s, first the work of Tate and then the detailed six-inch to one-mile mapping of the Geological Survey finally dispelled any notion that the sill was at a consistent stratigraphical level. Curiously, though the correct determination of the intrusive origin of the Whin Sill was one of Sedgwick's earliest and greatest achievements in Northern England, it was not deemed of sufficient importance to merit mention by his biographers.

Expansions for the linear-elastic contribution to the self-interaction force of dislocation curves

The self-interaction force of dislocation curves in metals depends on the local arrangement of the atoms and on the non-local interaction between dislocation curve segments. While these non-local segment–segment interactions can be accurately described by linear elasticity when the segments are further apart than the atomic scale of size $\varepsilon$ , this model breaks down and blows up when the segments are $O(\varepsilon)$ apart. To separate the non-local interactions from the local contribution, various models depending on $\varepsilon$ have been constructed to account for the non-local term. However, there are no quantitative comparisons available between these models. This paper makes such comparisons possible by expanding the self-interaction force in these models in $\varepsilon$ beyond the O(1)-term. Our derivation of these expansions relies on asymptotic analysis. The practical use of these expansions is demonstrated by developing numerical schemes for them, and by – for the first time – bounding the corresponding discretisation error.

SISTEM AGRIBISNIS INTEGRASI PADI KERBAU DAN POLA PEMELIHARAAN KERBAU DI KECAMATAN PAMPANGAN SUMATERA SELATAN

<p><em>Th</em><em>is study aimed </em><em>to determine and analyze the integrated rice-buffalo agribusiness system and to describe the pattern of buffalo raising in Pampangan District. This research was conducted in Pampangan District in July 2020. This research is a survey that took 30 samples purposively. Primary and secondary data obtained from the field survey were tabulated and analyzed descriptively-qualitatively. The integrated rice-buffalo agribusiness system in Pampangan District consists of the upstream subsystem, namely the provision of production facilities for rice-buffalo integration activities, the farming subsystem in the form of rice cultivation and livestock raising, the downstream subsystem, namely post-harvest and management of rice-buffalo waste used for organic fertilizer and silage. The supporting subsystem is that farmers have joined G</em><em>apoktan</em><em> and have received training from BPTP on making compost. </em><em>R</em><em>aising buffalo in Pampangan District is still traditional, which is almost entirely relying on nature. The buffaloes are released in the morning and put back in the afternoon, allowed to eat the feed in the grazing environment</em><em>. In contrast, </em><em>for the health of the buffalo, it is still done as necessary and not as intensive</em><em>.</em><em> The profit-sharing system between the owner and the custodian is known as the half system. The results of buffalo livestock production are obtained from the sale of buffalo and from the processing of buffalo milk production into sugar, sagon, curd or cow oil</em><em> (a popular local term in Pampangan Sub-district)</em><em>.</em></p>

Tambal: Investigasi pembelajaran tektonik berbasis budaya lokal

Artikel ini mengeksplorasi proses kegiatan tambal di Manado sebagai basis pembelajaran tektonik bagi mahasiswa arsitektur. Tambal adalah istilah setempat untuk kegiatan memperbaiki rumah ataupun benda lain yang bersifat tidak menyeluruh dan hanya mengganti bagian yang rusak. Pembelajaran tektonik bertujuan untuk memberikan pemahaman akan ekspresi seni dari sambungan ataupun pertemuan yang terjadi pada susunan struktur dan konstruksi. Pemahaman tektonik dari suatu desain kerap hanya dipahami dari keseluruhan susunan tersebut. Melalui kegiatan tambal, artikel ini berupaya menginvestigasi bagaimana mahasiswa arsitektur dapat memahami aspek tektonik melalui bagian-bagian pertemuan yang kemudian mempengaruhi keseluruhan tektonik yang hadir. Fokus kegiatan tambal dalam penelitian ini ditujukan untuk memperbaiki kondisi salah satu rumah sementara di kawasan Tempat Pembuangan Akhir (TPA) Sumompo Manado agar layak huni secara struktur. Dengan konteks tersebut, mahasiswa dihadapkan pada kompleksitas tektonik diambang batas minimal konstruksi, dan harus menemukan solusi arsitektural dengan tenggat waktu terbatas. Dari hasil pembelajaran tektonik melalui kegiatan tambal, mahasiswa menghasilkan pengembangan ekspresi desain tektonik yang berdasarkan kebutuhan untuk memperkuat bangunan tersebut. Kegiatan ini berkontribusi memperdalam pembelajaran tektonik dalam arsitektur berdasarkan aspek lokalitas untuk menghasilkan struktur yang lebih baik. This article explores the process of tambal in Manado as the basis of tectonic learning for architecture students. Tambal is a local term for house or objects repairing activities that only takes place in parts that are broken. Tectonic learning aims to provide students about understanding of the arts of joints that exists in a structural and construction assembly. Understanding of tectonic often only pay attention to the overall assembly of its parts. Through tambal activity, this article investigates how architecture students may understand tectonic aspects within the parts of the joints that later influence the overall configuration of assembly. In this research, the process of tambal was aimed to repair the condition of one of the temporary houses in the Sumompo landfill area in Manado to be structurally habitable. In such context, the students were faced with existing tectonic complexity below construction standards, and they were required to create an architectural solution within the limited time frame. By learning tectonic through tambal, the students were able to develop a tectonic design expression based on the need to strengthen the building itself. This activity contributes in deepening the process of tectonic learning in architecture based on local aspect to create a better quality of structural configuration.

Are Current Discontinuities in Molecular Devices Experimentally Observable?

An ongoing debate in the first-principles description of conduction in molecular devices concerns the correct definition of current in the presence of non-local potentials. If the physical current density j=(−ieℏ/2m)(Ψ*∇Ψ−Ψ∇Ψ*) is not locally conserved but can be re-adjusted by a non-local term, which current should be regarded as real? Situations of this kind have been studied for example, for currents in saturated chains of alkanes, silanes and germanes, and in linear carbon wires. We prove that in any case the extended Maxwell equations by Aharonov-Bohm give the e.m. field generated by such currents without any ambiguity. In fact, the wave equations have the same source terms as in Maxwell theory, but the local non-conservation of charge leads to longitudinal radiative contributions of E, as well as to additional transverse radiative terms in both E and B. For an oscillating dipole we show that the radiated electrical field has a longitudinal component proportional to ωP^, where P^ is the anomalous moment ∫I^(x)xd3x and I^ is the space-dependent part of the anomaly I=∂tρ+∇·j. For example, if a fraction η of a charge q oscillating over a distance 2a lacks a corresponding current, the predicted maximum longitudinal field (along the oscillation axis) is EL,max=2ηω2qa/(c2r). In the case of a stationary current in a molecular device, a failure of local current conservation causes a “missing field” effect that can be experimentally observable, especially if its entity depends on the total current; in this case one should observe at a fixed position changes in the ratio B/i in dependence on i, in contrast with the standard Maxwell equations. The missing field effect is confirmed by numerical solutions of the extended equations, which also show the spatial distribution of the non-local term in the current.

Modular Hamiltonians for the massless Dirac field in the presence of a boundary

We study the modular Hamiltonians of an interval for the massless Dirac fermion on the half-line. The most general boundary conditions ensuring the global energy conservation lead to consider two phases, where either the vector or the axial symmetry is preserved. In these two phases we derive the corresponding modular Hamiltonian in explicit form. Its density involves a bi-local term localised in two points of the interval, one conjugate to the other. The associated modular flows are also established. Depending on the phase, they mix fields with different chirality or charge that follow different modular trajectories. Accordingly, the modular flow preserves either the vector or the axial symmetry. We compute the two-point correlation functions along the modular flow and show that they satisfy the Kubo-Martin-Schwinger condition in both phases. The entanglement entropies are also derived.

Modular Hamiltonians for the massless Dirac field in the presence of a defect

We study the massless Dirac field on the line in the presence of a point-like defect characterised by a unitary scattering matrix, that allows both reflection and transmission. Considering this system in its ground state, we derive the modular Hamiltonians of the subregion given by the union of two disjoint equal intervals at the same distance from the defect. The absence of energy dissipation at the defect implies the existence of two phases, where either the vector or the axial symmetry is preserved. Besides a local term, the densities of the modular Hamiltonians contain also a sum of scattering dependent bi-local terms, which involve two conjugate points generated by the reflection and the transmission. The modular flows of each component of the Dirac field mix the trajectory passing through a given initial point with the ones passing through its reflected and transmitted conjugate points. We derive the two-point correlation functions along the modular flows in both phases and show that they satisfy the Kubo-Martin-Schwinger condition. The entanglement entropies are also computed, finding that they do not depend on the scattering matrix.