62 research outputs found

    Thermo-mechanical and anisotropic response of polymers in contact

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    Characteristics of Iconic High-rise Buildings

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    Iconography is a degree given to a building and an objective of its architectural design. The iconic high-rise buildings are important in various fields. Distinctiveness in skyscrapers is not achieved by chance or by exciting stories told about the building. Exaggeration in one of design elements does not achieve the uniqueness and architectural creativity. Iconicity is a product of gathering specific main cores. The iconic tall buildings have distinct characteristics that set them different from other buildings. This paper proposes to combine the distinctive characteristics of the iconic high-rise buildings from different references to form a unified and clear methodology used when designing to achieve the iconicity. The developed methodology can be relied upon in the critical analysis of those skyscrapers to determine the degree of iconicity, and to know the reasons for the failure of some tall buildings in achieving the iconicity with a simple and systematic methodology

    Characteristics of Iconic High-rise Buildings

    Get PDF
    Iconography is a degree given to a building and an objective of its architectural design. The iconic high-rise buildings are important in various fields. Distinctiveness in skyscrapers is not achieved by chance or by exciting stories told about the building. Exaggeration in one of design elements does not achieve the uniqueness and architectural creativity. Iconicity is a product of gathering specific main cores. The iconic tall buildings have distinct characteristics that set them different from other buildings. This paper proposes to combine the distinctive characteristics of the iconic high-rise buildings from different references to form a unified and clear methodology used when designing to achieve the iconicity. The developed methodology can be relied upon in the critical analysis of those skyscrapers to determine the degree of iconicity, and to know the reasons for the failure of some tall buildings in achieving the iconicity with a simple and systematic methodology

    Regioselective synthesis and antimicrobial studies of novel bridgehead nitrogen heterocycles containing the thienopyrimidinone skeleton

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    Versatile 2-(alkylthio)pyrimidine-type and 2-(phenacylamino)thiophene building blocks (4a-d) and 16 were obtained based on an ortho functionalized thiophene derivative 1. A novel series of thieno[2,3-d]pyrimidin-4-one derivatives with annelated bridgehead nitrogen heterocycles was synthesized starting from precursors 4 and 16 through convenient methods. Cyclocondensation of 2-(phenacylthio)pyrimidinone derivative (4b) with sulfuric acid led to the tricyclic thiazole derivative 5. Initial hydrazinolysis of 3-(carbethoxymethyl)pyrimidinone derivative (4d) followed by nitrous acid deamination of the formed N-aminolactam (7) to obtain a N-protodeamino analogue 8a, which on further treatment with formaldehyde and piperidine yielded the respective Mannich-type base 8b. On the other hand, initial hydrazinolysis of 3-unsubstituted pyrimidinone derivative 4a and subsequent acetylation gave the condensed 3-methyltriazole derivative 12, whereas the condensed pyrrole derivative 19 was obtained by heterocyclization of 2-phenacylamine derivative 16 with malononitrile. All newly-obtained thienopyrimidinones with annelated bridgehead nitrogen were screened for their antimicrobial activity against strains of a representative panel of Gram-positive and Gram-negative bacteria as well as fungi together with reference drugs. The compounds under investigation displayed generally good in vitro antibacterial and antifungal activities, with compound 8b that has a N-piperidinylmethyl moiety showing essentially the highest inhibition in both assays. Despite promising antimicrobial activity of N-1-substituted imidazole derivative 8b, the corresponding N-1-unsubstituted analogue 8a displayed poor activity. The heteroannelation of a N-(piperidinylmethyl)imidazole or 3-methyltriazole moiety to the thienopyrimidinone scaffold could be considered as a potential strategy for the development of new therapeutic antimicrobial agents

    Performance Evaluation and Design Tradeoffs of On-Chip Interconnect Architectures

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    Network-on-Chip (NoC) has been proposed as an alternative to bus-based schemes to achieve high performance and scalability in System-on-Chip (SoC) design. Performance analysis and evaluation of on-chip interconnect architectures are widely based on simulations, which become computationally expensive, especially for large-scale NoCs. In this paper, a Network Calculusbased methodology is presented to analyze and evaluate the performance and cost metrics, such as latency and energy consumption. The 2D Mesh, Spidergong and WK-recursive on-chip interconnect architectures are analyzed using this methodology and results are compared with those produced using simulations. The values obtained by simulations and by analysis show similar trends in the same order of magnitude. Furthermore, WK outperforms the other on-chip interconnects in all considered metric

    Optimized superpixel and AdaBoost classifier for human thermal face recognition

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    Infrared spectrum-based human recognition systems offer straightforward and robust solutions for achieving an excellent performance in uncontrolled illumination. In this paper, a human thermal face recognition model is proposed. The model consists of four main steps. Firstly, the grey wolf optimization algorithm is used to find optimal superpixel parameters of the quick-shift segmentation method. Then, segmentation-based fractal texture analysis algorithm is used for extracting features and the rough set-based methods are used to select the most discriminative features. Finally, the AdaBoost classifier is employed for the classification process. For evaluating our proposed approach, thermal images from the Terravic Facial infrared dataset were used. The experimental results showed that the proposed approach achieved (1) reasonable segmentation results for the indoor and outdoor thermal images, (2) accuracy of the segmented images better than the non-segmented ones, and (3) the entropy-based feature selection method obtained the best classification accuracy. Generally, the classification accuracy of the proposed model reached to 99% which is better than some of the related work with around 5%

    Flotation-separation of toxic metal ions from aqueous solutions using thiosemicarbazide derivatives as chelating agents and oleic acid as a surfactant

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    A simple and rapid procedure was developed for flotation-separation of toxic metal ions namely Hg2+, Mn2+ and Cd2+ from aqueous solutions. Thiosemicarbazide derivatives such as: 1-(amino-N-phenylmethanethio)-4-(pyridine-2-yl)thiosemicarbazide (H2PPS), N-phenyl-2-(pyridine-2-ylcarbamothioyl)hydrazinecarboxamide (H2PBO), 1-(amino(thioformyl)-N-phenylform)-4-(pyridine-2-yl)thiosemicarbazide (H2APO), and 1-(amino-N-(pyridine-3-yl) methanethio)-4-(pyridine-2-yl)thiosemicarbazide (H2PPY) have been used as organic chelating agents and oleic acid (HOL) as a surfactant. The different parameters affecting the flotation process namely, metal ion, ligands and surfactant concentrations, foreign ions (which are normally present in fresh and saline waters), pH and temperature are examined. About 100% of mercury, cadmium and manganese ions float at room temperature (~ 25 oC), at a metal:ligand ratio of 1:2  and at pH ~5. The procedure was successfully applied to recover Hg2+, Mn2+ and Cd2+ ions spiked into some water samples. The flotation mechanism is suggested based on some physical and chemical studies on the ligands and metal-complexes isolated from the floated layers

    Implications of regulatory policy for building secure agile software in Nigeria: A grounded theory

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    Nigeria is ranked second worldwide, after India, in reported incidences of cyberattacks. Attackers usually exploit vulnerabilities in software which may not have adequately considered security features during the development process. Agile methods have the potential to increase productivity and ensure faster delivery of software, although they tend to neglect non-functional requirements such as security. The implementation of government policies, such as the Nigeria Data Protection Regulation (NDPR) Act 2019, impacts the security activities carried out by agile teams. Despite its significance, there is a paucity of research on security issues especially in the Agile Software Development (ASD) domain. To address this gap, a grounded theory study was conducted with 15 agile software practitioners in Nigeria. Based on our analysis of the interview transcripts, we developed a grounded theory of the security challenges confronting agile practitioners. The four challenges identified were (a) a lack of collaboration betweensecurity and agile teams; (b) the tendency to use foreign software hosting companies; (c) a poor cybersecurity culture; and (d) the high cost of building secure agile software. We used these challenges to identify gaps within the existing secure ASD and found a lack of indigenous software hosting companies in Nigeria. Our study also revealed tensions between the Nigerian regulatory environment and agile software developers' compliance. While practitioners acknowledged the government's efforts, there were concerns about the practicality of implementing such legislation. We recommend government action to increase awareness of local software hosting companies' capabilities, and closer collaboration between agile and security teams. Thus, the novel contribution of this article is the development of the policy adherence challenges (PAC) model

    A New English/Arabic Parallel Corpus for Phishing Emails

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    Phishing involves malicious activity whereby phishers, in the disguise of legitimate entities, obtain illegitimate access to the victims’ personal and private information, usually through emails. Currently, phishing attacks and threats are being handled effectively through the use of the latest phishing email detection solutions. Most current phishing detection systems assume phishing attacks to be in English, though attacks in other languages are growing. In particular, Arabic is a widely used language and therefore represents a vulnerable target. However, there is a significant shortage of corpora that can be used to develop Arabic phishing detection systems. This paper presents the development of a new English-Arabic parallel phishing email corpus that has been developed from the anti-phishing share task text (IWSPA-AP 2018). The email content was to be translated, and the task had been allotted to 10 volunteers who had a university background and were English and Arabic language experts. To evaluate the effectiveness of the new corpus, we develop phishing email detection models using Term Frequency–Inverse Document Frequency (TF-IDF) and Multilayer Perceptron using 1258 emails in Arabic and English that have equal ratios of legitimate and phishing emails. The experimental findings show that the accuracy reaches 96.82% for the Arabic dataset and 94.63% for the emails in English, providing some assurance of the potential value of the parallel corpus developed
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