Density based clustering methods are proposed for clustering spatial databases with noise. Density Based Spatial Clustering of Applications with Noise (DBSCAN) can discover clusters of arbitrary ...shape and also handles outliers effectively. DBSCAN obtains clusters by finding the number of points within the specified distance from a given point. It involves computing distances from given point to all other points in the dataset. The conventional index based methods construct a hierarchical structure over the dataset to speed-up the neighbor search operations. The hierarchical index-structures fail to scale for datasets of dimensionality above 20. In this paper, we propose a novel graph-based index structure method Groups that accelerates the neighbor search operations and also scalable for high dimensional datasets. Experimental results show that the proposed method improves the speed of DBSCAN by a factor of about 1.5–2.2 on benchmark datasets. The performance of DBSCAN degrades considerably with noise due to unnecessary distance computations introduced by noise points while the proposed method is robust to noise by pruning out noise points early and eliminating the unnecessary distance computations. The cluster results produced by our method are exactly similar to that of DBSCAN but executed at a much faster pace.
•A graph-based index structure is built for speeding up neighbor search operations.•No additional inputs are required to build the index structure.•Proposed method is scalable for high-dimensional datasets.•Handles noise effectively to improve the performance of DBSCAN.
Highlights
Operations of metal oxide semiconductors gas sensors at room temperature under photoactivation are discussed.
Emerging two-dimensional (2D) materials-based gas sensors under light ...illumination are summarized.
The advantages and limitations of metal oxides and 2D-materials-based sensors in gas sensing at room temperature under photoactivation are highlighted.
Room-temperature gas sensors have aroused great attention in current gas sensor technology because of deemed demand of cheap, low power consumption and portable sensors for rapidly growing Internet of things applications. As an important approach, light illumination has been exploited for room-temperature operation with improving gas sensor’s attributes including sensitivity, speed and selectivity. This review provides an overview of the utilization of photoactivated nanomaterials in gas sensing field. First, recent advances in gas sensing of some exciting different nanostructures and hybrids of metal oxide semiconductors under light illumination are highlighted. Later, excellent gas sensing performance of emerging two-dimensional materials-based sensors under light illumination is discussed in details with proposed gas sensing mechanism. Originated impressive features from the interaction of photons with sensing materials are elucidated in the context of modulating sensing characteristics. Finally, the review concludes with key and constructive insights into current and future perspectives in the light-activated nanomaterials for optoelectronic gas sensor applications.
Metal oxide semiconductors-based gas sensors have been extensively explored due to their high sensing response, cost-effectivity, long-term stability, and simple fabrication. However, their ...utilization at low operating temperature is still challenging. Thus, reduction in power consumption is highly essential for long-term usage of gas sensors. ZnO nanostructures-based gas sensors are one of the most eligible candidates where a real-time detection of explosive and toxic gases is needed. On this subject, numerous efforts have been made to improve the sensing response at reduced working temperature with the assistance of various methods. In this report, several techniques related to the synthesis of ZnO nanostructures and their efficient performance in sensing are reviewed. The report primarily focuses on different means of improving the sensing properties, such as functionalization of noble metal nanoparticles, doping of metals, inclusion of carbonaceous nanomaterials, using nanocomposites of different MO, UV activation, and post-treatment method of high-energy irradiation on ZnO nanostructures, with their possible sensing mechanisms. This study will therefore shed light on future proposals of ZnO-based gas sensors showing high sensitivity even at low operating temperature.
Survey on software defect prediction techniques Mahesh Kumar Thota; Francis H Shajin; P. Rajesh
International Journal of Applied Science and Engineering,
01/2020, Letnik:
17, Številka:
4
Journal Article
Recenzirano
Recent advancements in technology have emerged the requirements of hardware and software applications. Along with this technical growth, software industries also have faced drastic growth in the ...demand of software for several applications. For any software industry, developing good quality software and maintaining its eminence for user end is considered as most important task for software industrial growth. In order to achieve this, software engineering plays an important role for software industries. Software applications are developed with the help of computer programming where codes are written for desired task. Generally, these codes contain some faulty instances which may lead to the buggy software development cause due to software defects. In the field of software engineering, software defect prediction is considered as most important task which can be used for maintaining the quality of software. Defect prediction results provide the list of defect-prone source code artefacts so that quality assurance team scan effectively allocate limited resources for validating software products by putting more effort on the defect-prone source code. As the size of software projects becomes larger, defect prediction techniques will play an important role to support developers as well as to speed up time to market with more reliable software products. One of the most exhaustive and pricey part of embedded software development is consider as the process of finding and fixing the defects. Due to complex infrastructure, magnitude, cost and time limitations, monitoring and fulfilling the quality is a big challenge, especially in automotive embedded systems. However, meeting the superior product quality and reliability is mandatory. Hence, higher importance is given to V＆V (Verification ＆ Validation). Software testing is an integral part of software V＆V, which is focused on promising accurate functionality and long-term reliability of software systems. Simultaneously, software testing requires much effort, cost, infrastructure and expertise as the development. The costs and efforts elevate in safety critical software systems. Therefore, it is essential to have a good testing strategy for any industry with high software development costs. In this work, we are planning to develop an efficient approach for software defect prediction by using soft computing based machine learning techniques which helps to predict optimize the features and efficiently learn the features.
The current work aims at assessing the single cylinder, diesel engine fueled with nano-emulsion of orange peel oil biodiesel. The orange oil was elicited from orange peels through solvent extraction ...method then converted into methyl ester. By using the solvent extraction method, the orange peel oil (Limonene) yield was achieved up to 82.3%. Later, nanofluid was prepared in two different concentrations by doping 50 and 100 ppm of TiO2 nanoparticles. The orange oil biodiesel nano-emulsions namely OOME-T50 and OOME-T100 were prepared with the proportion of 88% of pure orange oil methyl ester, 10% of TiO2 nanofluid and 2% of span-80 as a surfactant. Experiments were performed with prepared fuels (pure OOME, OOME-T50 and OOME-T100) in a test engine and its results were discussed. The BTE of the engine increased up to 1.4% and 3.0% with OOME OOME-T50 and OOME-T100 fuels when correlated with pure OOME fuel. However, neat diesel fuel indicates maximum BTE at peak load condition. Significant reduction of about 24.2%, 9.7%, 18.4%, 16.0% in smoke, NOx, CO and HC were observed for OOME-T100 nano-emulsion fuel as correlated to pure OOME at peak load. Also, it can be noted that the cylinder peak pressure and heat release rate were increased for OOME nano-emulsion fuels when compared to pure OOME at greatest power output.
•Orange oil extracted from orange peels waste was effectively utilized as a fuel for diesel engine.•Solvent extraction method shows the better yield for orange oil.•Nano emulsion with OOME fuel blend offers 1.4%–3.0% improvement in BTE with raw OOME fuel.•Overall diesel engine tailpipe emissions were reduced for the fuel blend nano emulsion + OOME.•Cylinder pressure and HRR was increased for nano emulsion + OOME fuel blend with raw OOME fuel.
Acute renal failure is a serious complication of the anticancer drug cisplatin. The potential role of baicalein, a naturally occurring bioflavonoid on cisplatin-induced renal injury is unknown. Here, ...we assessed the effect of baicalein against a murine model of cisplatin-induced acute renal failure and investigated the underlying possible mechanisms. Renal function, kidney histology, inflammation, oxidative stress, renal mitochondrial function, proteins involved in apoptosis, nuclear translocation of Nrf2 and effects on intracellular signaling pathways such as MAPKs, and NF-κB were assessed. Pretreatment with baicalein ameliorated the cisplatin-induced renal oxidative stress, apoptosis and inflammation and improved kidney injury and function. Baicalein inhibited the cisplatin-induced expression of iNOS, TNF-α, IL-6 and mononuclear cell infiltration and concealed redox-sensitive transcription factor NF-κB activation via reduced DNA-binding activity, IκBα phosphorylation and p65 nuclear translocation in kidneys. Further studies demonstrated baicalein markedly attenuated cisplatin-induced p38 MAPK, ERK1/2 and JNK phosphorylation in kidneys. Baicalein also restored the renal antioxidants and increased the amount of total and nuclear accumulation of Nrf2 and downstream target protein, HO-1 in kidneys. Moreover, baicalein preserved mitochondrial respiratory enzyme activities and inhibited cisplatin-induced apoptosis by suppressing p53 expression, Bax/Bcl-2 imbalance, cytochrome c release and activation of caspase-9, caspase-3 and PARP. Our findings suggest that baicalein ameliorates cisplatin-induced renal damage through up-regulation of antioxidant defense mechanisms and down regulation of the MAPKs and NF-κB signaling pathways.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This article investigates the time-dependent MHD heat transfer flow of Jeffrey fluid from a stretching sheet, the topic significance to non-Newtonian viscoelastic material processing. Using ...similarity transformations, the governing coupled non-linear PDE’s are remodel into ODE’s with suitable free stream and wall boundary conditions. The developed non-dimensional non-linear problem is revealed to be analysed by several key thermosphysical and rheological parameters, namely, Jeffrey fluid parameter (
), Deborah number (
), Prandtl number (Pr), buoyancy parameter (
), magnetic parameter (
) and unsteadiness parameter (
). The semi-exact differential transform technique is applied to elucidate the coupled nonlinear governing equation of non-Newtonian Jeffrey fluid problem. Also, the solution is validated with numerical results attained via the MATLAB bvp4c function. Excellent accurateness is attained through the DTM approach. Further validation with available consequences from the existing literature is incorporated. The results indicate that fluid velocity and temperature are boosted with increasing Deborah number and stretching parameter however it shows a decreasing trend with Jeffrey fluid parameter and convection parameter. It also shows when augmenting the magnetic parameter which reduces the flow and increases the thickness of the boundary layer.
This paper proposes an algorithm for coordinated control of the distributed generators integrated to a dc microgrid (DCMG), in islanded and grid connected modes of operation. The proposed DCMG ...connects various types of nonconventional energy sources, storage system to the dc, and three-phase, as well as single-phase ac loads. A control strategy for three-phase voltage source inverter to integrate the three-phase load, as well as utility grid into the DCMG, under various operating scenarios, has also been proposed. The proposed control strategy uses a combination of the feed-back and feed-forward control loops. Dual proportional integral controllers for ac voltage regulation and inner current control have been suggested in two rotating direct- and quadrature- axis synchronous reference frames for controlling the respective positive and negative sequence components. Simulations are carried out to verify the robustness of the proposed algorithm and control strategy under different operating conditions including fault scenario and its effectiveness in maintaining the dc voltage of the microgrid.
In gas sensor technology, current research efforts are focused on developing a high performance miniaturized gas sensor operating at room temperature. In recent years, layered semiconducting material ...MoS2 has gained vast attention in sensing field owing to the detection of a variety of analytes at room temperature, high surface‐to‐volume ratio, and also provided substantial advantages in emerging flexible and wearable sensing field. Herein, a state‐of‐art overview of the utilization of burgeoning MoS2 research in gas sensing applications is provided. The synthesis of some exciting different nanostructures and hybrids of the MoS2 on a rigid as well as flexible substrate is summarized, as they play an important role in tuning the gas sensing characteristic of the MoS2. The gas sensing performance of the MoS2 sensors with proposed mechanisms is discussed in the context of a wide range of different morphologies/nanostructures, nanocomposites, van der Waals heterostructures, and photoactivation effects. Moreover, rapid advances and growing significance of the MoS2 on the emerging flexible gas sensing platform are also highlighted. Finally, some insights into new challenges and future perspectives in the promising MoS2 research for gas sensing applications are presented.
Herein, a state‐of‐art overview of the utilization of burgeoning 2D semiconducting material MoS2 research in gas sensing field is presented. New challenges and future perspectives in the promising MoS2 research for gas sensing applications are also comprehensively discussed.
Abstract
We have designed a series of new conjugated donor–acceptor-based macrocyclic molecules using state-of-the-art computational methods. An alternating array of donors and acceptor moieties in ...these macrocycle molecules are considered to tune the electronic and optical properties. The geometrical, electronic, and optical properties of newly designed macrocyclic molecules are fully explored using various DFT methods. Five conjugated macrocycles of different sizes are designed considering various donor and acceptor units. The selected donor and acceptors, viz., thiophene (PT), benzodithiophene (BDT), dithienobenzodithiophene (DTBDT), diketopyrrolopyrrole (DPP), and benzothiazole (BT), are frequently found in high performing conjugated polymer for different organic electronic applications. To fully assess the potential of these designed macrocyclic derivatives, analyses of frontier molecular orbital energies, excited state energies, energy difference between singlet–triplet states, exciton binding energies, rate constants related to charge transfer at the donor–acceptor interfaces, and electron mobilities have been carried out. We found significant structural and electronic properties changes between cyclic compounds and their linear counterparts. Overall, the cyclic conjugated D–A macrocycles’ promising electronic and optical properties suggest that these molecules can be used to replace linear polymer molecules with cyclic conjugated oligomers.
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