148 research outputs found
Sand production simulation under true-triaxial stress conditions
Laboratory sanding experiments were carried out under true-triaxial stress conditions. The objective was to investigate the effect of state of stresses and fluid flow on the mechanism of sanding, and the development of the failure zone around the borehole. The experiments were conducted on 100×100×100 mm3 cubic samples of synthetic sandstones. The samples were prepared based on an established procedure developed to produce weakly consolidated sandstone samples with identical physico-mechanical properties. The properties of the synthetic sandstone samples were determined by conducting a series of standard rock mechanics tests on cylindrical plugs. Using a true-triaxial stress cell (TTSC), cubic samples were subjected to true-triaxial stresses and radial fluid flow from the outer boundaries into the borehole. The maximum and intermediate principal stresses were applied laterally in both cases while the effect of changing the lateral stresses on the development of the failure zone around borehole was monitored. It was observed that the geometry (i.e. width and depth) of the failure zone developed around the borehole is a function of the lateral stresses ratio (i.e. lateral stress anisotropy). The experiments were also simulated numerically using ABAQUS in order to validate and interpret the results from the experiments. A good agreement was obtained between the results of both methods, which confirms the importance of lateral stress anisotropy on the evolution of sanding. The observations and results of these experiments and numerical simulations will be presented and discussed
Perbedaan Pengaruh Penerapan Metode inquiri dan Eksperimen terhadap Hasil Belajar IPA ditinjau dari Keaktifan Siswa Kelas IV SD di Dabin V Kecamatan Purwodadi Tahun Pelajaran 2012/2013
Penelitian ini bertujuan untuk mengetahui perbedaan pengaruh penggunaan metode inquiry dan metode eksperimen terhadap hasil belajar ditinjau dari keaktifan belajar siswa kelas IV pada mata pelajaran IPA SD Negeri Dabin V Kec. Purwodadi Kab. Grobogan.Subjek dalam penelitian ini adalah siswa kelas IV SD Negeri 1 Candisari tahun ajaran 2012/2013 yang berjumlah 85 siswa, yang terdiri dari 27 siswa SD Negeri I Candisari dengan perlakuan metode eksperimen, 30 Siswa dari SD Negeri II Candisari dengan menggunakan metode Inquiry sedangkan untuk kelas Uji coba dari SD Negeri I Genuksuran dengan jumlah Siswa 28. Teknik pengumpulan data yang digunakan adalah menggunakan tes.Data penelitian dianalisis dengan menggunakan teknik analisis kuantitatif.Hasil penelitian menunjukan bahwa metode inquiry dan eksperimen berpengaruh terhadap hasil belajar yang di tinjau dari keaktifan belajar siswa kelas IV pada mata pelajaran IPA SD Negeri Dabin V. Hal ini ditunjukan dari hasil perhitungan dengan menggunakan Uji Anava 2X3. Keyword: metode inquiry ,metode eksperimen, mata pelajaran IP
Supersymmetric Yang-Mills Theory and Riemannian Geometry
We introduce new local gauge invariant variables for N=1 supersymmetric
Yang-Mills theory, explicitly parameterizing the physical Hilbert space of the
theory. We show that these gauge invariant variables have a geometrical
interpretation, and can be constructed such that the emergent geometry is that
of N=1 supergravity: a Riemannian geometry with vector-spinor generated
torsion. Full geometrization of supersymmetric Yang-Mills theory is carried
out, and geometry independent divergences associated to the inversion of a
differential operator with zero modes -- that were encountered in the
non-supersymmetric case -- do not arise in this situation.Comment: 21 pages, LaTex, Added discussions and references, Final version for
Nuclear Physics
An Investigation of LLMs' Inefficacy in Understanding Converse Relations
Large Language Models (LLMs) have achieved remarkable success in many formal
language oriented tasks, such as structural data-to-text and semantic parsing.
However current benchmarks mostly follow the data distribution of the
pre-training data of LLMs. Therefore, a natural question rises that do LLMs
really understand the structured semantics of formal languages. In this paper,
we investigate this problem on a special case, converse binary relation. We
introduce a new benchmark ConvRe focusing on converse relations, which contains
17 relations and 1240 triples extracted from popular knowledge graph completion
datasets. Our ConvRE features two tasks, Re2Text and Text2Re, which are
formulated as multi-choice question answering to evaluate LLMs' ability to
determine the matching between relations and associated text. For the
evaluation protocol, apart from different prompting methods, we further
introduce variants to the test text and few-shot example text. We conduct
experiments on three popular LLM families and have observed various scaling
trends. The results suggest that LLMs often resort to shortcut learning and
still face challenges on our proposed benchmark.Comment: Accepted by EMNLP 202
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A genomic copy number variant analysis implicates the MBD5 and HNRNPU genes in Chinese children with infantile spasms and expands the clinical spectrum of 2q23.1 deletion
Background: Infantile spasms (IS) is a specific type of epileptic encephalopathy associated with severe developmental disabilities. Genetic factors are strongly implicated in IS, however, the exact genetic defects remain unknown in the majority of cases. Rare mutations in a single gene or in copy number variants (CNVs) have been implicated in IS of children in Western countries. The objective of this study was to dissect the role of copy number variations in Chinese children with infantile spasms. Methods: We used the Agilent Human Genome CGH microarray 180 K for genome-wide detection of CNVs. Real-time qPCR was used to validate the CNVs. We performed genomic and medical annotations for individual CNVs to determine the pathogenicity of CNVs related to IS. Results: We report herein the first genome-wide CNV analysis in children with IS, detecting a total of 14 CNVs in a cohort of 47 Chinese children with IS. Four CNVs (4/47 = 8.5%) (1q21.1 gain; 1q44, 2q31.1, and 17p13 loss) are considered to be pathogenic. The CNV loss at 17p13.3 contains PAFAH1B1 (LIS1), a causative gene for lissencephaly. Although the CNVs at 1q21.1, 1q44, and 2q23.1 have been previously implicated in a wide spectrum of clinical features including autism spectrum disorders (ASD) and generalized seizure, our study is the first report identifying them in individuals with a primary diagnosis of IS. The CNV loss in the 1q44 region contains HNRNPU, a strong candidate gene recently suggested in IS by the whole exome sequencing of children with IS. The CNV loss at 2q23.1 includes MBD5, a methyl-DNA binding protein that is a causative gene of ASD and a candidate gene for epileptic encephalopathy. We also report a distinct clinical presentation of IS, microcephaly, intellectual disability, and absent hallux in a case with the 2q23.1 deletion. Conclusion: Our findings strongly support the role of CNVs in infantile spasms and expand the clinical spectrum associate with 2q23.1 deletion. In particular, our study implicates the HNRNPU and MBD5 genes in Chinese children with IS. Our study also supports that the molecular mechanisms of infantile spasms appear conserved among different ethnic backgrounds
Molecular Etiology of Hearing Impairment in Inner Mongolia: mutations in SLC26A4 gene and relevant phenotype analysis
<p>Abstract</p> <p>Background</p> <p>The molecular etiology of hearing impairment in Chinese has not been thoroughly investigated. Study of <it>GJB2 </it>gene revealed that 30.4% of the patients with hearing loss in Inner Mongolia carried <it>GJB2 </it>mutations. The <it>SLC26A4 </it>gene mutations and relevant phenotype are analyzed in this study.</p> <p>Methods</p> <p>One hundred and thirty-five deaf patients were included. The coding exons of <it>SLC26A4 </it>gene were sequence analyzed in 111 patients, not including 22 patients carrying bi-allelic <it>GJB2 </it>mutations or one patient carrying a known <it>GJB2 </it>dominant mutation as well as one patient with <it>mtDNA </it>1555A>G mutation. All patients with <it>SLC26A4 </it>mutations or variants were subjected to high resolution temporal bone CT scan and those with confirmed enlarged vestibular aqueduct and/or other inner ear malformation were then given further ultrasound scan of thyroid and thyroid hormone assays.</p> <p>Results</p> <p>Twenty-six patients (19.26%, 26/135) were found carrying <it>SLC26A4 </it>mutation. Among them, 17 patients with bi-allelic <it>SLC26A4 </it>mutations were all confirmed to have EVA or other inner ear malformation by CT scan. Nine patients were heterozygous for one <it>SLC26A4 </it>mutation, including 3 confirmed to be EVA or EVA and Mondini dysplasia by CT scan. The most common mutation, IVS7-2A>G, accounted for 58.14% (25/43) of all <it>SLC26A4 </it>mutant alleles. The shape and function of thyroid were confirmed to be normal by thyroid ultrasound scan and thyroid hormone assays in 19 of the 20 patients with EVA or other inner ear malformation except one who had cystoid change in the right side of thyroid. No Pendred syndrome was diagnosed.</p> <p>Conclusion</p> <p>In Inner Mongolia, China, mutations in <it>SLC26A4 </it>gene account for about 12.6% (17/135) of the patients with hearing loss. Together with <it>GJB2 </it>(23/135), <it>SLC26A4 </it>are the two most commonly mutated genes causing deafness in this region. Pendred syndrome is not detected in this deaf population. We established a new strategy that detects <it>SLC26A4 </it>mutations prior to the temporal bone CT scan to find EVA and inner ear malformation patients. This model has a unique advantage in epidemiologic study of large deaf population.</p
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