325 research outputs found

    A hybrid three-phased approach in requirement elicitation

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    Requirement elicitation is one of the most important activities in requirement engineering and allocating limited amount of time in this activity is considered to significantly contribute towards failure of software projects. Having quality requirements is also greatly influenced by the techniques utilized during requirement elicitation process. The adoption of a single requirement elicitation technique within software development projects has various drawbacks. As solution, hybrid techniques are being considered as the way towards comprehensive requirements engineering. This paper investigates the hybrid requirement elicitation technique to tackle the challenges developers are facing in the process of software development. In this paper, the combination of 3 requirement elicitation techniques, namely use of questionnaire, interview and prototyping in a unified framework is investigated during the implementation of an online educational system

    Towards improving the security of low-interaction honeypots: insights from a comparative analysis

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    The recent increase in the number of security attacks by cyber-criminals on small businesses meant that security remained a concern for such organizations. In many such cases, detecting the attackers remained a challenge. A common tool to augment existing attack detection mechanisms within networks involves the use of honeypot systems. A fundamental feature of low-interaction honeypots is to be able to lure intruders, but the effectiveness of such systems has nevertheless been affected by various constraints. To be able to secure honeypots systems, it is important to firstly determine its requirements, before taking appropriate actions to ensure that the identified requirements have been achieved. This paper critically examines how existing low-interaction honeypot systems abide to major requirements before recommending how their security could be improved

    Evaluation of potentially toxic metals (PTMs) accumulation and translocation by Albizia lebbeck from industrial soil

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    Field samples of Albizia lebbeck, deciduous tree with drought tolerant properties, growing on industrial soil (Challawa Industrial Estate) were collected and separated into leaves, stems, roots and associated ground soil to assess the accumulation and translocation of Six Potentially Toxic Metals (PTMs) (Zn, Cu, Cd, Cr, Pb and Ni ) from the soil. Atomic Absorption Spectroscopy (AAS) was used to assess their levels. The bioaccumulation/ transfer of metals from roots to shoots and from soil to roots were evaluated in terms of translocation and bioconcentration factor. TF values of 1.22 , 1.41, 3.57 and 1.86 for Cu , Cd , Pb and Ni respectively indicate that A. lebbeck was efficient in translocation of PTMs from roots to shoots and follows the trend Cu > Zn > Ni > Cr respectively. This depicts the plant as a likely candidate for phytoextraction of Zn, Cu, Cr and Ni. BCF values of Zn (0.94), Cu (0.85), Cd (1.37), Cr (1.25), Pb (2.3) and Ni (1.66) were noted for the PTMs. This reveals that A. lebbeck may be suitable for phytostabilization of Zn and Cr in the contaminated soils as it retains high concentration of these PTMs in its roots in the study area

    Accumulation and Translocation of Potentially Toxic Elements (PTEs) from Industrial Soil by a Woody Drought Tolerant Tree, Eucalyptus citridora

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    Field samples of Eucalyptus citridora, a drought tolerant tree, growing in an industrial area with high anthropogenic activities (Challawa) were collected and were separated into leaves, stems and roots. The aim was to assess the levels of accumulation and translocation of six Potentially Toxic Elements (PTEs) (Zn, Cu, Cd, Cr, Pb and Ni) from the soil media. Atomic Absorption Spectroscopy (AAS) was used to assess the concentrations. The bioaccumulation/ transfer of metals from roots to shoots and from soil to roots were evaluated in terms of translocation (TF) and bioconcentration factors (BCF). TF values of 1.58, 1.98 , 1.07, and 1.26 for Zn , Cu , Cr and Ni respectively indicated that Eucalyptus citridora was efficient in translocation of PTEs from roots to shoots and follows the trend Cu>Zn > Ni > Cr. This is an indication that the plant is therefore suitable for phytoextraction of Zn, Cu, Cr and Ni. BCF values of Zn (0.94), Cu (0.85), Cd (1.37), Cr (1.25), Pb (2.3) and Ni(1.66)were recorded for the elements under investigation. This show that Eucalyptus citridora may be a suitable candidate for phytostabilization of Cd and Pb in the contaminated soils as it retains high concentration of these metals in its roots as seen in the study area

    On the fuzzy nature of constructed algebraic structure

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    Cyber Security and the Internet of Things : vulnerabilities and Security requirements

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    The Internet of Things (IoT) enables billions of embedded computing devices to connect to each other. It includes various kinds of devices, e.g., sensors, actuators, RFID tags, or smartphones, which are very different in terms of size, weight, functionality and capabilities. Their success is very noticed and the number of threats and attacks against IoT devices and services are on the increase as well. In IoT, The objects can be discovered, controlled and managed from the Internet. This articulation, which represents a strong point of the IoT, also inherit all the problematic of the security already present in the Internet. The latter rests even with renewed acuteness in this new environment, because of its characteristics special. It is important to analyze how conventional security requirements (CIA, AAA, etc.) as well as those related to respect for privacy can be broken down in this new environment. This paper is an attempt to classify different vulnerabilities, besides analyze and characterize security requirements

    Effects of disc speed and height of flow mechanism of a solid manure spreader on uniformity of spreading and swath width

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    The aim of this study was to investigate the effects of disc speed and height of flow mechanism of a solid manure spreader in order to maintain uniformity of spread and swath width for optimum crop growth. The study was done using complete randomized design with three factors considered: tractor forward speed, height of flow mechanism (broadcasters) gate opening rates, (15, 30, 45cm) and disc speed (150, 300, 450rpm) applied according to SAE S341.2, 1999 test code. Results obtained and compared with an imported spreader shows that the developed spreader recorded the highest application rate of 4082.1kg/ha against that of the imported spreader of 1875.3kg/ha while the swath width was 9.5m compared to 9.0m of the imported. Results obtained also shows that the spreader gave a more uniform spread pattern of manure at a lower openning of 15cm height of flow mechanism and lesser disc speed of 150rpm. Disc speed and height of flow mechanism were found to be the major determining factor influencing spreading uniformity and swath width of cow dung manure for optimum crop growth

    Evaluation of qualitative phytochemicals and antifungal activity of aqueous leaf extract of Senna tora on downy mildew of cabbage

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    This study was embarked upon to evaluate the efficacy of aqueous extracts of Senna tora leaf against Perenospora parasitica, causing downy mildew on cabbage. Phytochemical analysis of the leaf extracts revealed the presence of some secondary metabolites (Tannins, Saponins, Flavonoid, Glycosides, Alkaloids, Phenolic compounds and Carbohydrates) which have been reported to have antimicrobial effects. Assays were performed using extract concentrations of 1000, 500, 250, 125 mg/ml by agar well diffusion technique. Results obtained, revealed a significant difference in diameter of mycelial zone of inhibition between the concentrations. Highest zone of inhibition was recorded at 1000 and 500 mg/ml (20 and 15 mm) respectively. Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) were determined and recorded at 250 mg/ml. The antifungal screening revealed that the extract exhibited inhibitory activities at varying concentrations against the downy mildew pathogen. These activities observed could be attributed to the presence of active metabolites contained in the extract.Keywords: Aqueous leaf extract, Downy mildew, Perenospora parasitica and Senna tor

    Fluoroscopic-guided sacroiliac joint injections for treatment of chronic axial low back pain in a tertiary Hospital in Nigeria: a preliminary study

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    Background: The injection of mixture of plain bupivacaine and triamcinolone acetonide into the sacroiliac joint (SIJ) to relieve chronic low back pain is uncommon in the West African sub-region. The objective of this study was to demonstrate the efficacy or otherwise of fluoroscopic-guided SI joint injection in the management of chronic axial low back pain in Nigeria.Design: This was a prospective observational interventional studySetting: The study was carried out at a tertiary hospital in NigeriaParticipants: Twenty-six patients with SI joint pain, based on IASP diagnostic criteria, who presented to our unit over 36 months from March 2012 to March 2015 and.Interventions: Fluoroscopic-guided injections of 5mls mixture of bupivacaine and triamcinolone acetonide into the sacro-iliac (SI) joints of 26 patients with SI joint pain out of 116 patients who were offered different interventions for chronic low back pain. The patients were followed up for year and pain intensity and functional status were assessed at 3-, 6- and 12 months post-intervention.Main outcome measures: Pain relief and functional improvement were the main outcome measures.Results: The mean numeric rating score (NRS) and Oswestry Disability index (ODI) score in 14 (53.9%) patients at 12 months post-interventions were significantly lower compared with baseline values; 3.19 ± 1.10 vs 8.54 ±1.14 p=0.000 and 25.35 ± 5.40 vs 37.54 ±8.41, p=0.000 respectively.Conclusion: Fluoroscopic-guided steroid injection into the SI joint resulted into reduction in pain intensity and improved physical function in the majority of patients with SI joint pain. Funding: Not declaredKeywords: Axial low back pain, sacroiliac joint, steroid injection, fluoroscopy, pain relie

    New cosmological solutions and stability analysis in full extended thermodynamics

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    The Einstein's field equations of FRW universes filled with a dissipative fluid described by full theory of causal transport equations are analyzed. New exact solutions are found using a non-local transformations on the nonlinear differential equation for the Hubble factor. The stability of the de Sitter and asymptotically friedmannian solutions are analyzed using Lyapunov function method.Comment: 13 pages, LaTeX 2.09. To be published in International Journal of Modern Physics
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