Concern localization using information retrieval: An empirical study on Linux kernel

10.1109/WCRE.2011.72Proceedings - Working Conference on Reverse Engineering, WCRE92-9

Thiourea-based receptors for an on recognition and sensing

Anion recognition and sensing have been developed into an important research subject in supramolecular chemistry. Noncovalent interactions such as hydrogen bonding, electrostatic interaction, hydrophobic interaction, etc. are the most important binding forces existing in the anion-receptor binding complexes, which forms the basis of designing anion binding receptors. The design, construction and anion recognition and sensing of thiourea-based receptors following mainly multi hydrogen bonding interactions are reviewed. 51 key references were cited to represent the related advances in the past 5 years

A new rheological model and its application in mountain tunnelling

The time-dependent features of soft rock, named rheology generally, should be taken into account in the long-term design and maintenance of mountain tunnels. Based on the classic Burger-MC rheological model, a Burger-deterioration rheological model is proposed in this paper and is implemented in the numerical codes FLAC3D. A deterioration threshold and two deterioration ratios are introduced in this model to consider the time-dependent strength deterioration aspect of the rock mass. The proposed model is applied to an engineering instance (Ureshino Tunnel Line I, Nagasaki, Japan) to account for the delayed deformations that occurred after its completion since November 1992. The delayed crown settlement and invert upheaval computed from simulations are featured by an exponential characteristic and a stair-typed characteristic, respectively, which agree well with the in-site monitoring data qualitatively. In addition, the realistic rheological parameters involved in the proposed model can be back-analyzed from the in-site monitoring data

A new method for the characterization of microcracks based on seepage characteristics

Microcracks are the main seepage channels and reservoir space for oil and gas in dense sandstone reservoirs, and the degree of development dominates the reservoir’s high and stable production capacity. A new method has been devised to address the lack of quantitative identification and characterization methods for microcrack networks. The method is based on core stress sensitivity, permeability anisotropy, and two-phase seepage rule testing. By improving upon the traditional black oil model, this method can accurately calculate the impact that microcracks of varying degrees of development have on the capacity of tight oil reservoirs. The study shows that 1) the higher the degree of microcrack development, the stronger the reservoir stress sensitivity and the greater the permeability anisotropy. As the degree of microcrack development increases, the irreducible water saturation decreases, the residual oil saturation gradually increases, and the oil–water two-phase co-infiltration zone becomes more extensive and smaller. The degree of microcrack development in tight reservoirs can be characterized based on the seepage characteristic parameters; 2) a microcrack characterization method and classification criteria have been established. It is based on stress sensitivity coefficients, permeability anisotropy parameters, and phase seepage characteristics in cores with different microcrack development degrees. For the first time, the method enables a macroscopic-level description of microcrack seepage; 3) numerical calculations show that the degree of microcrack development significantly affects the reservoir’s oil production and water production. The higher the degree of microcrack development, the higher the reservoir’s initial oil production and cumulative oil production. However, when the degree of microcrack development is too high, the microcracks are connected, thus exhibiting the nature of large fractures. This strengthens the bypassing communication effect and causes the microscopic inhomogeneity to strengthen, the oil production decreases rapidly, and water production increases quickly at the later stage. This research result enriches the reservoir microcrack characterization and evaluation system, which has essential theoretical guidance and practical significance for the rational and effective development of tight oil and tight sandstone gas

Markovian Geology Prediction Approach and its Application in Mountain Tunnels

A geology prediction approach based on Markov random process and Bayesian updating procedure is presented in this article. It can dynamically predict the ground conditions ahead of tunnel face in a probabilistic way with very low cost, when the tunnel face advances and new geological information is revealed. The application case study on Chuangshi Tunnel project shows that the prediction results fit the real grounds condition well, especially for the short range ahead of face. This approach can be regarded as a good complement to the geophysical prospecting approach during the construction of mountain tunnels

Whole-genome resequencing of 472 Vitis accessions for grapevine diversity and demographic history analyses

Despite the importance of grapevine cultivation in human history and the economic values of cultivar improvement, large-scale genomic variation data are lacking. Here the authors resequence 472 Vitis accessions and use the identified genetic variations for domestication history, demography, and GWAS analyses

Influence of confining pressure-dependent Young’s modulus on the convergence of underground excavation

The actual convergence of an excavation located in fractured rock mass or the soft rock is largely different with the theoretical result in many cases. Experimental results showed that the influence of confining pressure on Young\u27s modulus is very significant. This paper attempted to illustrate the influence of the confining pressure-dependent Young\u27s modulus in the ground reaction analyses of mountain tunnel. Firstly, the relationship between Young\u27s modulus and confining pressure was described as a non-linear function according to the test results. Based on the plane strain axial symmetry assumption and the incremental theory of plasticity, equilibrium equations and compatibility equations of rock mass around a circular tunnel were deduced theoretically. Based on fourth Runge-Kutta method, a semi-analytical solution was achieved. Considering the effect of confining pressure on Young\u27s modulus, the stress and deformation of rock mass around tunnel was calculated by both analytical and numerical methods. The influence of confining pressure-dependent Young\u27s modulus in surrounding rock was estimated quantitatively. Finally, Tawara saka Tunnel in Japan was taken as an example to explain the influence of confining pressure-dependent Young\u27s modulus. The results showed that the error with respect to the monitoring data was largely reduced with the confining pressure-dependent Young\u27s modulus model, which indicated the necessity of considering the non-uniform distribution of Young\u27s modulus

Studies on the key parameters in segmental lining design

The uniform ring model and the shell-spring model for segmental lining design are reviewed in this article. The former is the most promising means to reflect the real behavior of segmental lining, while the latter is the most popular means in practice due to its simplicity. To understand the relationship and the difference between these two models, both of them are applied to the engineering practice of Fuzhou Metro Line I, where the key parameters used in both models are described and compared. The effective ratio of bending rigidity η reflecting the relative stiffness between segmental lining and surrounding ground and the transfer ratio of bending moment ξ reflecting the relative stiffness between segment and joint, which are two key parameters used in the uniform ring model, are especially emphasized. The reasonable values for these two key parameters are calibrated by comparing the bending moments calculated from both two models. Through case studies, it is concluded that the effective ratio of bending rigidity η increases significantly with good soil properties, increases slightly with increasing overburden, and decreases slightly with increasing water head. Meanwhile, the transfer ratio of bending moment ξ seems to only relate to the properties of segmental lining itself and has a minor relation with the ground conditions. These results could facilitate the design practice for Fuzhou Metro Line I, and could also provide some references to other projects with respect to similar scenarios

Bilateral Multiple Extraocular Muscle Metastasis from Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) rarely metastasizes to the extra ocular muscles (EOMs). We present a case of bilateral metastasis of HCC to the EOMs and focus on the magnetic resonance imaging (MRI) features. Orbital MRI revealed nodular enlargement of bilateral multiple EOMs, with isointensity on T1-weighted images and heterogeneous, intermediate-to-high signal intensity on T2-weighted images, and showed mild-to-significant heterogeneous contrast enhancement with gadolinium. Physicians should be aware of this rare cause of EOM enlargement, understand the radiologic characteristics of EOM metastasis, and thus make appropriate treatment strategy