698 research outputs found
Numerical Solution of Some Nonlinear Volterra Integral Equations of the First Kind
In this paper, the solving of a class of the nonlinear Volterra integral equations (NVIE) of the first kind is investigated. Here, we convert NVIE of the first kind to a linear equation of the second kind. Then we apply the operational Tau method to the problem and prove convergence of the presented method. Finally, some numerical examples are given to show the accuracy of the method
Meningkatkan Hasil Belajar Fisika Menggunakan Strategi Question Student Have Berbantuan Animasi di SMP
This research aims to improve student learning outcomes using Question Student Have strategy with animation media on light reflection in class VIII of MTS Al-Islamiya Rahaudatul Peniti Luar. There are 27 students involved in the study of this classroom action research. Based on data analysis concluded that the used of Question Student Have strategies with animation media can improve student learning outcomes in light reflection. Before the research was conducted, the average of student learning outcomes reached KKM (Criteria Complete Minimal) of 65.5. The number of students who reached KKM were 10 people with a percentage of 36.7%. After being given the action I, the average result of learning was 66.67. The number of students who reached KKM were 17 people with a percentage of 63%. The percentage of students who reached KKM increased by 26.3%. After being given a second action, the average learning outcomes was 73.3. The number of students who reached KKM for 21 people with a percentage of 77.8%. The percentage of students who reached KKM increased by 14.8%
Understanding complex magnetic order in disordered cobalt hydroxides through analysis of the local structure
In many ostensibly crystalline materials, unit-cell-based descriptions do not
always capture the complete physics of the system due to disruption in
long-range order. In the series of cobalt hydroxides studied here,
Co(OH)(Cl)(HO), magnetic Bragg diffraction reveals a
fully compensated N\'eel state, yet the materials show significant and open
magnetization loops. A detailed analysis of the local structure defines the
aperiodic arrangement of cobalt coordination polyhedra. Representation of the
structure as a combination of distinct polyhedral motifs explains the existence
of locally uncompensated moments and provides a quantitative agreement with
bulk magnetic measurements and magnetic Bragg diffraction
Magneto-elastic coupling and competing entropy changes in substituted CoMnSi metamagnets
We use neutron diffraction, magnetometry and low temperature heat capacity to
probe giant magneto-elastic coupling in CoMnSi-based antiferromagnets and to
establish the origin of the entropy change that occurs at the metamagnetic
transition in such compounds. We find a large difference between the electronic
density of states of the antiferromagnetic and high magnetisation states. The
magnetic field-induced entropy change is composed of this contribution and a
significant counteracting lattice component, deduced from the presence of
negative magnetostriction. In calculating the electronic entropy change, we
note the importance of using an accurate model of the electronic density of
states, which here varies rapidly close to the Fermi energy.Comment: 11 pages, 9 figures. Figures 4 and 6 were updated in v2 of this
preprint. In v3, figures 1 and 2 have been updated, while Table II and the
abstract have been extended. In v4, Table I has updated with relevant neutron
diffraction dat
Evaluation of patient outcome and satisfaction after surgical treatment of adolescent idiopathic scoliosis using scoliosis research society-30
Background: Adolescent idiopathic scoliosis (AIS) may lead to physical and mental problems. It also can adversely affect patient satisfaction and the quality of life. In this study, we assessed the outcomes and satisfaction rate after surgical treatment of AIS using scoliosis research society-30 questionnaire (SRS-30). Methods: We enrolled 135 patients with AIS undergoing corrective surgery. Patients were followed for at least 2 years. We compared pre- and post-operative x-rays in terms of Cobb's angles and coronal balance. At the last visit, patients completed the SRS-30 questionnaire. We then assessed the correlation between radiographic measures, SRS-30 total score, and patient satisfaction. Results: Cobb's angle and coronal balance improved significantly after surgery (P<0.001). The scores of functional activity, pain, self-image/cosmesis, mental health, and satisfaction were 27±4.3, 26±2.5, 33±5.2, 23±3.5, and 13±1.8, respectively. The total SRS-30 score was 127±13. Radiographic measures showed significant positive correlation with satisfaction and SRS-30 total scores. There was also a positive correlation between satisfaction and self-image/cosmesis domain scores. Conclusions: The greater the radiographic angles were corrected the higher the SRS-30 total score and patient satisfaction were. It is intuitive that the appearance and cosmesis is of most important factor associated with patient satisfaction. © 2015 BY THE ARCHIVES OF BONE AND JOINT SURGERY
Correlated Differential Privacy: Feature Selection in Machine Learning
© 2005-2012 IEEE. Privacy preserving in machine learning is a crucial issue in industry informatics since data used for training in industries usually contain sensitive information. Existing differentially private machine learning algorithms have not considered the impact of data correlation, which may lead to more privacy leakage than expected in industrial applications. For example, data collected for traffic monitoring may contain some correlated records due to temporal correlation or user correlation. To fill this gap, in this article, we propose a correlation reduction scheme with differentially private feature selection considering the issue of privacy loss when data have correlation in machine learning tasks. The proposed scheme involves five steps with the goal of managing the extent of data correlation, preserving the privacy, and supporting accuracy in the prediction results. In this way, the impact of data correlation is relieved with the proposed feature selection scheme, and moreover the privacy issue of data correlation in learning is guaranteed. The proposed method can be widely used in machine learning algorithms, which provide services in industrial areas. Experiments show that the proposed scheme can produce better prediction results with machine learning tasks and fewer mean square errors for data queries compared to existing schemes
Electronic structure and magnetic properties of the spin-1/2 Heisenberg system CuSe2O5
A microscopic magnetic model for the spin-1/2 Heisenberg chain compound
CuSe2O5 is developed based on the results of a joint experimental and
theoretical study. Magnetic susceptibility and specific heat data give evidence
for quasi-1D magnetism with leading antiferromagnetic (AFM) couplings and an
AFM ordering temperature of 17 K. For microscopic insight, full-potential DFT
calculations within the local density approximation (LDA) were performed. Using
the resulting band structure, a consistent set of transfer integrals for an
effective one-band tight-binding model was obtained. Electronic correlations
were treated on a mean-field level starting from LDA (LSDA+U method) and on a
model level (Hubbard model). In excellent agreement of experiment and theory,
we find that only two couplings in CuSe2O5 are relevant: the nearest-neighbour
intra-chain interaction of 165 K and a non-frustrated inter-chain coupling of
20 K. From a comparison with structurally related systems (Sr2Cu(PO4)2,
Bi2CuO4), general implications for a magnetic ordering in presence of
inter-chain frustration are made.Comment: 20 pages, 8 figures, 3 table
Realising the potential of mHealth to improve asthma and allergy care : how to shape the future
Non peer reviewe
Quantification of spatial subclonal interactions enhancing the invasive phenotype of pediatric glioma.
Diffuse midline gliomas (DMGs) are highly aggressive, incurable childhood brain tumors. They present a clinical challenge due to many factors, including heterogeneity and diffuse infiltration, complicating disease management. Recent studies have described the existence of subclonal populations that may co-operate to drive pro-tumorigenic processes such as cellular invasion. However, a precise quantification of subclonal interactions is lacking, a problem that extends to other cancers. In this study, we combine spatial computational modeling of cellular interactions during invasion with co-evolution experiments of clonally disassembled patient-derived DMG cells. We design a Bayesian inference framework to quantify spatial subclonal interactions between molecular and phenotypically distinct lineages with different patterns of invasion. We show how this approach could discriminate genuine interactions, where one clone enhanced the invasive phenotype of another, from those apparently only due to the complex dynamics of spatially restricted growth. This study provides a framework for the quantification of subclonal interactions in DMG
Giant crystal-electric-field effect and complex magnetic behavior in single-crystalline CeRh3Si2
Single-crystalline CeRh3Si2 was investigated by means of x-ray diffraction,
magnetic susceptibility, magnetization, electrical resistivity, and specific
heat measurements carried out in wide temperature and magnetic field ranges.
Moreover, the electronic structure of the compound was studied at room
temperature by cerium core-level x-ray photoemission spectroscopy (XPS). The
physical properties were analyzed in terms of crystalline electric field and
compared with results of ab-initio band structure calculations performed within
the density functional theory approach. The compound was found to crystallize
in the orthorhombic unit cell of the ErRh3Si2 type (space group Imma -- No.74,
Pearson symbol: oI24) with the lattice parameters: a = 7.1330(14) A, b =
9.7340(19) A, and c = 5.6040(11) A. Analysis of the magnetic and XPS data
revealed the presence of well localized magnetic moments of trivalent cerium
ions. All physical properties were found to be highly anisotropic over the
whole temperature range studied, and influenced by exceptionally strong
crystalline electric field with the overall splitting of the 4f1 ground
multiplet exceeding 5700 K. Antiferromagnetic order of the cerium magnetic
moments at TN = 4.70(1)K and their subsequent spin rearrangement at Tt =
4.48(1) K manifest themselves as distinct anomalies in the temperature
characteristics of all investigated physical properties and exhibit complex
evolution in an external magnetic field. A tentative magnetic B-T phase
diagram, constructed for B parallel to the b-axis being the easy magnetization
direction, shows very complex magnetic behavior of CeRh3Si2, similar to that
recently reported for an isostructural compound CeIr3Si2. The electronic band
structure calculations corroborated the antiferromagnetic ordering of the
cerium magnetic moments and well reproduced the experimental XPS valence band
spectrum.Comment: 32 pages, 12 figures, to appear in Physical Review
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