329,322 research outputs found
An Empirical analysis of Open Source Software Defects data through Software Reliability Growth Models
No full textThe purpose of this study is to analyze the reliability growth of Open Source Software (OSS) using Software Reliability Growth Models (SRGM). This study uses defects data of twenty five different releases of five OSS projects. For each release of the selected projects two types of datasets have been created; datasets developed with respect to defect creation date (created date DS) and datasets developed with respect to defect updated date (updated date DS). These defects datasets are modelled by eight SRGMs; Musa Okumoto, Inflection S-Shaped, Goel Okumoto, Delayed S-Shaped, Logistic, Gompertz, Yamada Exponential, and Generalized Goel Model. These models are chosen due to their widespread use in the literature. The SRGMs are fitted to both types of defects datasets of each project and the their fitting and prediction capabilities are analysed in order to study the OSS reliability growth with respect to defects creation and defects updating time because defect analysis can be used as a constructive reliability predictor. Results show that SRGMs fitting capabilities and prediction qualities directly increase when defects creation date is used for developing OSS defect datasets to characterize the reliability growth of OSS. Hence OSS reliability growth can be characterized with SRGM in a better way if the defect creation date is taken instead of defects updating (fixing) date while developing OSS defects datasets in their reliability modellin
Andreimyrme pakistanensis Lelej and Ullah, sp. nov.
No full textAndreimyrme pakistanensis Lelej and Ullah, sp. nov. (Figs 9–15) Diagnosis. The male of Andreimyrme pakistanensis is similar to that of the type species A. long [holotype is examined, deposited in ZMMU] in having a strong mandible with additional inner tooth, and in having a lamellate volsella with long setae. It can be distinguished from the latter species in having a median subbasal tubercle on S 8 (lacking in A. long), and in having weakly depressed clypeus (deeply depressed in A. long). Description. MALE. Body length 7.2 –12.0 mm (holotype – 10.2 mm). Head width 0.8 X thorax width including tegulae. Ocelli small, POD: OOD 0.8 X. Clypeus weakly depressed with elevated curved preapical carina and short median basal carina. Clypeus mostly glabrous, finely punctate laterally, without basal tubercle. Occipital carina well developed. Mandible strong, not excised beneath, dilated and tridentate apically, with inner tooth (Figs 12–15). Relation of pedicel and three first flagellomeres 0.6: 1.0: 2.7: 2.7. Antennal tubercles very strong, latero-basally with deep furrow, dorsal carina sharply angulate and touching inner margin of eye. Frons, vertex, pronotum, mesoscutum, scutellum and mesopleura densely punctate. Mesoscutum with complete notauli and short parapsidal furrows. Propodeum reticulate. Mesopleura beneath with precoxal curved carina. Metasternum longitudinally striate. Tegulae densely punctate, punctures sparser on disc. Forewing venation as in Fig. 9. S 1 carinate beneath. Metasomal segment 2 densely punctate, punctures sparser on tergal disc. T 2 with long lateral felt line. S 2 without any trace of felt line. T 3 –T 6 densely punctate. T 7 densely punctate, apical half with median glabrous area. S 8 glabrous, sparsely punctate, with subbasal blunt tubercle. Genitalia laterally and dorsally as in Figs. 10, 11. Body, legs, and antennae black. Wings infuscated. Mandibles preapically red. Fore tibial spurs yellowish, mid- and hind tibial spurs whitish. Lower frons, genae, antennal tubercles, pronotum dorsally, mesopleura and legs clothed with dense, recumbent, short and scattered, long, erect whitish pubescence. Upper frons, vertex, scutellum, metanotum medially, propodeum, T 1 –T 5, S 1 –S 8 with sparse whitish setae. Mesoscutum, tegulae, and T 6 –T 7 with black setae mixed with a few whitish ones on T 6. Scutellum and metanotum laterally and propodeum basally covered with dense, whitish micropubescence. T 1 –T 5 with apical bands of whitish setae. S 2 –S 6 with apical fringes of whitish setae. FEMALE. Unknown. Type material. Holotype ♂, Pakistan: Margalla Hills National Park, 5.VII. 2005, MT, H. Khurram & M. Fida [PMNH]. Paratypes. Margalla Hills National Park, 24, 28, 30.VI, 5, 7, 12, 18, 27.VII, 1, 9.VIII. 2005, MT, H. Khurram & M. Fida, 23 ♂ [PMNH, IBSS]. Distribution. Pakistan. Etymology. The specific name is a Latin adjective derived from Pakistan, referring to the country where the species has been found.Published as part of Lelej, Arkady S., Ullah, Mishkat & Mahmood, Khalid, 2007, Additions to the knowledge of the Mutillidae (Hymenoptera) of Pakistan, pp. 53-60 in Zootaxa 1444 on pages 56-57, DOI: 10.5281/zenodo.17609
Ephutomma himalayana Lelej and Ullah, sp. nov.
No full textEphutomma himalayana Lelej and Ullah, sp. nov. (Figs 16–25) Diagnosis. The male of Ephutomma himalayana is most similar to that of E. kerzhneri (Lelej 1977) [holotype is examined, deposited in ZIN] in the key to the Palaearctic species (Lelej 1985). It can be distinguished from the latter species in having an additional subapical tooth on the ventral mandibular margin (lacking in E. kerzhneri), in having a subbasal ventral mandibular tooth that is unidentate apically (bidentate in E. kerzhneri), and in having infuscated wings (hyaline with infuscated apex in E. kerzhneri). Description. MALE. Body length 5.4–9.6 mm (holotype – 7.2 mm). Head width 1.2 X head height. Ocelli small, POD: OOD 0.5–0.6 X. Clypeus with anterior shiny depression bordered by arcuate carina which ends anteriorly in two tubercles. Occipital carina weak. Hypostomal carina weakly dilated. Mandible dilated, with inner tooth and additional subapical ventral tooth, bidentate apically, excised beneath, subbasal ventral tooth with one apex (Figs 18–21). Relation of pedicel and three first flagellomeres 0.5: 1.0: 2.0: 2.0. Frons without process between antennal tubercles. Ocellar area weakly elevated. Frons, vertex, pronotum, mesoscutum, scutellum, and mesopleura densely punctate. Mesoscutum with complete notauli and short parapsidal furrows. Parascutal carinae well developed. Propodeum reticulate with median elongated and two rounded cells on dorsum. Mesopleura beneath without precoxal tubercle. Posterior coxae carinate inside, carina not dentate apically. Tegulae punctate, disc and posterior margin glabrous. Forewing venation as in Fig. 16. S 1 carinate beneath. Metasomal segment 2 densely punctate, punctures sparser on tergal disc. T 2 with long lateral felt line. S 2 without any trace of felt line. T 3 –T 6 densely punctate. T 7 densely punctate, apically with median glabrous area. Genitalia laterally, dorsally, and ventrally as in Figs. 22–25. Body, legs, and antennae black; pronotum, mesoscutum, scutellum, tegulae, metanotum, upper part of mesopleura, and upper part of metapleura red. Wings infuscated. Mandibles preapically piceous. Fore tibial spurs yellowish, mid- and hind tibial spurs whitish. Lower frons, genae, antennal tubercles, scape, tibiae, and tarsi covered with dense, recumbent short and scattered, long, erect whitish pubescence. Upper frons, vertex, pronotum, scutellum, tegulae, metanotum medially, propodeum, T 1 –T 8, S 1 –S 8, and femorae covered with sparse whitish setae. Mesoscutum with sparse black setae. Scutellum and metanotum laterally covered with dense recumbent silvery micropubescence. T 1 –T 3 with apical fringe of dense yellowish setae. S 2 –S 5 with apical fringes of sparse whitish setae. FEMALE. Unknown. Type material. Holotype ♂, Nepal, Chitwan National Park, Sauraha, 27 ° 34 'N, 84 ° 29 'E, 200 m, 31.V. 1997, M. Hauser [Oberoesterreichisches Landesmuseum Linz, Austria]. Paratypes. Nepal: the same label as holotype, 1 ♂ [IBSS]; the same place, 31.V– 4.VI. 1997, M. Hauser, 3 ♂ [col. Schmid-Egger, IBSS]. Pakistan: Margalla Hills National Park, 1, 13, 23.VI, 1, 12.VII, 8.IX. 2005, MT, H. Khurram & M. Fida, 6 ♂ [PMNH, IBSS]; 25.VIII. 2006, MT, H. Khurram & M. Fida, 1 ♂ [PMNH]. Distribution. Pakistan, Nepal. Etymology. The specific name is a Latin adjective derived from the Himalaya Mountain range, referring to the region where the species has been found.Published as part of Lelej, Arkady S., Ullah, Mishkat & Mahmood, Khalid, 2007, Additions to the knowledge of the Mutillidae (Hymenoptera) of Pakistan, pp. 53-60 in Zootaxa 1444 on page 58, DOI: 10.5281/zenodo.17609
Microwave Sensing Dataset for Noninvasive Monitoring of Ventricle Enlargement due to Alzheimer's Disease
No full textThe research hypothesis for this study was to investigate the potential of microwave imaging using unidirectional antennas for monitoring neurodegenerative diseases, specifically Alzheimer's disease. The data was collected using a wearable device and measurement setup that included five lamb brain phantoms that were designed to mimic the lateral ventricle enlargement due to Alzheimer's disease .The data include both the magnitude and the phase for each of the five phantoms at each discrete frequency.The most interesting thing about this study is that the data from the microwave imaging with unidirectional antennas was able to accurately show the enlargement of the lateral ventricles and the presence of cerebral spinal fluid in the lamb brain phantoms. This suggests that this method could be used to track neurodegenerative diseases like Alzheimer's.This data can be interpreted and used by researchers and scientists working on developing novel signal processing and imaging techniques, as well as those interested in validating simulation results. It can also be used to further investigate the potential of microwave imaging for monitoring neurodegenerative diseases
Denitrification and greenhouse gas emissions in natural and semi-natural terrestrial ecosystems [LTLS]
No full textUllah, S.; Sgouridis, F. (2017). Denitrification and greenhouse gas emissions in natural and semi-natural terrestrial ecosystems [LTLS]. NERC Environmental Information Data Centre. https://doi.org/10.5285/d970c095-129a-41ac-9c82-950ab780458
Fabrication of superhydrophillic and graded index antireflective double layer coating for solar photovoltaics module using aerosol impact deposition assembly
No full textIn the study presented, a double layer graded refractive indices silicon dioxide nano-porous coating was deposited on glass substrates to reduce the optical losses in solar photovoltaics using the technique referred as Aerosol Impact Deposition Assembly (AIDA). The proposed system consists of the gaseous precursors namely Silane, Oxygen and Helium that ionize in the plasma reaction chamber of AIDA to form silica nanoparticles. The nanoparticles size and shape can be controlled by the flow rates of each precursor gas, pressure difference in reaction and deposition chamber, and the proportion of helium gas. The assembly accelerates the silica nanoparticles towards deposition chamber with high impact speed using a small slit nozzle where they are coated on a glass/silicon substrate placed on a moving stage. Using this technique, thin film silica nanoparticle double layer was coated and characterized using Transmission electron microscope (TEM), Scanning Electron Microscope and Atomic Force Microscope to determine the particle shape, size, and morphology respectively. The average nanoparticle size determined from TEM image was 12.5 nm while the porosity of the top and bottom thin films was 60% and 42%, respectively. The UV-Spectroscopy results showed that reflection losses were decreased from 9% to 2% in a broad range of solar spectrum i.e., wavelength 300-1200 nm. In addition, due to high porosity and sufficient roughness, the coated thin film showed excellent self-cleaning and antifogging properties with water contact angle less than 5o. Moreover, short current density of the cell was increased by 1.4 mA/cm2, from 39.1 mA/cm2 to 40.5 mA/cm2, which shows enhancement in the electrical performance of the solar cell
Double overt-leaf shaped cpw-fed four port uwb mimo antenna
No full textThis paper presents a 4 × 4 multi-input multi-output antenna array for ultra-wideband applications. The single element of the array is comprised of a modified co-planar waveguide-fed double overt-leaf shaped patch radiator. The co-planar ground is optimized to achieve maximum impedance matching in the operating frequency band. The results show that the single antenna element offers an impedance bandwidth of 13.2 GHz starting from 3.2 GHz to 16.7 GHz. It is also observed from the results that the antenna offers good radiation characteristics and acceptable gain for the frequency band of interest. Furthermore, a 4 × 4 MIMO array is designed by utilizing the polarization diversity technique. To improve the isolation performance among antenna elements, a fan-shaped decoupler is introduced on the other side of the substrate, which ensures minimum isolation of 20 dB. Moreover, the proposed MIMO array operates in the frequency range of 2.75– 16.05 GHz. The proposed MIMO array is fabricated and measured for the validation of simulation results, and it is observed that both the results are well in agreement
Lateral boundary effects in centrifuge foundation tests
No full textUllah, S ORCiD: 0000-0002-5522-5341Large deformation finite-element analyses were conducted to explore the effect of the container lateral boundary in centrifuge tests where a large offshore foundation is tested. A spudcan foundation, typically used to support jack-up drilling rigs, was penetrated into uniform clay, uniform sand and sand overlying clay stratigraphies under rough and smooth lateral boundary conditions. The effect that the proximity of the container lateral boundary has on the measured load–penetration response is quantified. The boundary impact varies with the soil profile and boundary roughness, and for sand-only or sand-over-clay conditions the required separation between the foundation and the container boundary is far greater than in clay-only conditions. In most cases, during large penetration of the spudcan foundation, the largest influence from the lateral boundary was on peak resistance, and diminished during the subsequent deeper penetration. For practical use, a centrifuge container design chart is proposed to check whether the dimensions are adequate for the foundation and model size to be used in an experiment. It is shown that the results from many earlier studies could have been potentially influenced by container boundary effects
Design-Space Exploration of Biologically-Inspired SNN Models for Application-Specific Many-Core Systems
No full textUllah S. Design-Space Exploration of Biologically-Inspired SNN Models for Application-Specific Many-Core Systems. Universität Bielefeld; 2025
Recent Findings in (Ti)POSS-based Polymer Systems
No full textNovel polymer hybrids based on a Ti-containing polyhedral oligomeric silsesquioxane-(Ti)POSS-and two polymer matrices-polyamide 6 (PA6) and a styrene-maleic anhydride copolymer (PSMA)-have been prepared by different approaches (namely, in situ polymerization, melt blending, grafting) in order to investigate the dispersion level of (Ti)POSS within the organic polymer matrices in view of potential in situ catalytic activity of the metal. The chemical characterization of the prepared hybrid systems, performed by infrared spectroscopy and nuclear magnetic resonance, and their morphological analysis, evaluated by electron microscopy and X-ray diffraction, have shown that it is possible to homogeneously distribute and finely disperse (Ti)POSS at nanometric level within PA6 and PSMA. In this manner, an easy incorporation of metal functionalities into the above polymer matrices has been achieved and extension to other polymer systems can be foreseen
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