Multi‐level reranking approach for bug localization

Bug fixing has a key role in software quality evaluation. Bug fixing starts with the bug localization step, in which developers use textual bug information to find location of source codes which have the bug. Bug localization is a tedious and time consuming process. Information retrieval requires understanding the programme's goal, coding structure, programming logic and the relevant attributes of bug. Information retrieval (IR) based bug localization is a retrieval task, where bug reports and source files represent the queries and documents, respectively. In this paper, we propose BugCatcher, a newly developed bug localization method based on multi‐level re‐ranking IR technique. We evaluate BugCatcher on three open source projects with approximately 3400 bugs. Our experiments show that multi‐level reranking approach to bug localization is promising. Retrieval performance and accuracy of BugCatcher are better than current bug localization tools, and BugCatcher has the best Top N, Mean Average Precision (MAP) and Mean Reciprocal Rank (MRR) values for all datasets.     

A Combined Interleaving Technique for Trellis Coded MPSK Systems in Rayleigh Fading Channels

Freedom of mobility is the latesttrend in the evolution of digital communicationsystems. In these systems bandwidth and powerconstraints limit the mobility of the users. TCM(trellis coded modulation) is a combined coding andmodulation scheme which increases the productivity ofa digital communication system without increasing thetransmitted power or the required bandwidth. A mobilecommunication channel is affected from noise andfading because of the multipath propagation. On aRayleigh fading channel, coding should be used withtechniques which uncorrelate the received energy ofeach consecutive coded symbol. Interleaving is one ofthese techniques and used to make burst errors intorandom errors which can be corrected by errorcorrecting codes. In this paper, the trellis codingsystem which combines a regular convolutional encoder,bit interleaver, coordinate interleaver, and anappropriate decoder is considered. The analytical biterror probability upper bounds are derived for the8-PSK TCM system whose diversity is increased by usinga regular 2/3 rate convolutional code followed bythree bit interleavers and a 8-PSK signal mapperfollowed by two coordinate interleavers. Theanalytical and simulation results show that toincrease the diversity of the trellis coded M-PSKsystems in Rayleigh fading channels is the primary keyfor reliable transmission of high quality voice anddigital data.     

Fibroblast Growth Factor 21 Response in a Preclinical Alcohol Model of Acute-on-Chronic Liver Injury

Background and Aims: Fibroblast growth factor (FGF) 21 has recently been shown to play a potential role in bile acid metabolism. We aimed to investigate the FGF21 response in an ethanol-induced acute-on-chronic liver injury (ACLI) model in Abcb4^−/− mice with deficiency of the hepatobiliary phospholipid transporter. Methods: Total RNA was extracted from wild-type (WT, C57BL/6J) and Abcb4⁻/⁻ (KO) mice, which were either fed a control diet (WT-Cont and KO-Cont groups; n = 28/group) or ethanol diet, followed by an acute ethanol binge (WT-EtOH and KO-EtOH groups; n = 28/group). A total of 58 human subjects were recruited into the study, including patients with alcohol-associated liver disease (AALD; n = 31) and healthy controls (n = 27). The hepatic and ileal expressions of genes involved in bile acid metabolism, plasma FGF levels, and bile acid and its precursors 7α- and 27-hydroxycholesterol (7α- and 27-OHC) concentrations were determined. Primary mouse hepatocytes were isolated for cell culture experiments. Results: Alcohol feeding significantly induced plasma FGF21 and decreased hepatic Cyp7a1 levels. Hepatic expression levels of Fibroblast growth factor receptor 1 (Fgfr1), Fgfr4, Farnesoid X-activated receptor (Fxr), and Small heterodimer partner (Shp) and plasma FGF15/FGF19 levels did not differ with alcohol challenge. Exogenous FGF21 treatment suppressed Cyp7a1 in a dose-dependent manner in vitro. AALD patients showed markedly higher FGF21 and lower 7α-OHC plasma levels while FGF19 did not differ. Conclusions: The simultaneous upregulation of FGF21 and downregulation of Cyp7a1 expressions upon chronic plus binge alcohol feeding together with the invariant plasma FGF15 and hepatic Shp and Fxr levels suggest the presence of a direct regulatory mechanism of FGF21 on bile acid homeostasis through inhibition of CYP7A1 by an FGF15-independent pathway in this ACLI model. Lay Summary: Alcohol challenge results in the upregulation of FGF21 and repression of Cyp7a1 expressions while circulating FGF15 and hepatic Shp and Fxr levels remain constant both in healthy and pre-injured livers, suggesting the presence of an alternative FGF15-independent regulatory mechanism of FGF21 on bile acid homeostasis through the inhibition of Cyp7a1.     

Mesoscopic nonequilibrium thermodynamics treatment of the grain boundary thermal grooving induced by the anisotropic surface drift diffusion

A systematic study based on the self-consistent dynamical simulations is presented for the grain boundary thermal grooving problem by strictly following the irreversible thermodynamic theory of surfaces and interfaces with singularities [T. O. Ogurtani, J. Chem. Phys. 124, 144706 (2006)]. This approach furnishes us to have auto-control on the otherwise free-motion of the grain boundary triple junction without presuming any equilibrium dihedral (wetting) angles at the edges. The effects of physicochemical properties and the anisotropic surface diffusivity on the transient grooving behavior, which takes place at the early stage of the scenario, were considered. We analyzed the experimental thermal grooving data reported for tungsten in the literature, and compared them with the carried simulation results. This investigation showed that the observed changes in the dihedral angles are strictly connected to the transient behavior of the simulated global system, and manifest themselves at the early stage of the thermal grooving phenomenon.     

Preparation of Lead Zirconate by Homogeneous Precipitation and Calcination

Antiferroelectric PbZrO₃ has been synthesized by homogeneous precipitation from aqueous solutions in the presence of urea (NH₂CONH₂) and calcination for 6 h at 700°C. SEM studies displayed the presence of submicrometer powder, with a significant degree of agglomeration.     

Variation of the key structural,morphological, and optical properties of nanostructured copper(II) oxide (CuO) thin films using surfactant CAPB as a capping agent

Journal of Materials Science: Materials in Electronics - In this study, copper(II) oxide thin-film samples were fabricated by the SILAR technique in the absence and presence of surfactant as a...     

Synthesis of a side chain liquid crystalline polycarbonate with a chiral backbone

We report the experimental demonstration of a novel and environmentally benign supercritical carbon dioxide (ScCO₂) technique that yields an optically active, side chain liquid crystalline polycarbonate in a single‐step reaction. The obtained polymer is worthwhile, since it is highly stereoregular and can find applications in an enlarged mesomorphic temperature range compared to its acrylic analogues. The synthesized materials were characterized by IR, ¹H‐NMR, and ¹³C‐NMR, while the thermal properties were measured by DSC. Polarized optical micrograph and wide angle X‐ray diffraction were used for the mesogenic property characterization of the copolymer. The transfer chirality from the backbone to the mesophase is demonstrated on the optical microscopy textures. Being consistent with the ¹³C‐NMR, X‐ray implies an ordered polymeric structure. The DSC analysis of the copolymer indicates that the T_i (the clearing point temperature) value does not change dramatically, whereas a pronounced decrease in T_g (the glass transition temperature) value is observed from that of its acrylic analogues. Hence, the obtained polymer exhibits another practical benefit by widening the mesomorphic temperature range. This study is the insightful combination of material processing and chemical design that elucidates the advantages of ScCO₂ application, in terms of liquid crystallinity and the tacticity of the obtained polymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1915–1921, 2006     

Electrochemical poly(1,3-phenylenediamine) synthesis as enzyme immobilization media

Electrochemical polymerization of the 1,3-phenylenediamine in the presence of glucose oxidase with KCl aqueous electrolyte at a potential of 0.800 V versus Ag–AgCl produces adherent poly(1,3-phenylenediamine) containing enzyme (glucose oxidase) film on a platinum electrode. Polymeric sensor prepared in this one-step procedure can be used to determine hydrogen peroxide formed as the result of the enzymatic reaction between glucose and glucose oxidase in the presence of O₂. The amperometric responses of the resultant enzyme electrode to glucose were rapid, reaching steady-state values within 4–5 s, and there was a linear relationship between glucose concentration and obtained current up to 6 mM. Polymeric sensor was stable for more 3 months. The glucose selectivity of enzyme electrode was determined in the presence of some interfering substances, such as lactose, sucrose, urea, uric acid, paracetamol, and ascorbic acid. Also, the effects of buffer concentration, storage conditions, and temperature on the steady-state amperometric responses were studied. Moreover, the Arrhenius activation energy for the enzymatic reaction was calculated. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:145–152, 1998