1,291 research outputs found

    Energy absorption capability of thin-walled aluminium tubes under crash loading

    Get PDF
    This paper investigates the interaction of design factors such as tube thickness, tube length, and tube cross-sectional aspect ratio, along with friction and impacting mass on crashworthiness parameters such as specific energy absorption contact time, peak force and crush distance. The impact velocity is assumed to be constant at 15 m/s. The focus is on rectangular aluminium tubes and the analysis was carried out by using a validated finite element model. The analysis shows that the factors are not independent of each other and there is some degree of interaction between them. It was found that the trigger mechanism is a very important design factor to be included in the design of thin-walled tubes for energy absorption applications. The effect of the friction coefficient was found to be insignificant and finally, based on the interactions, it can be concluded that the most effective design would be a larger tube with small wall thickness, and a larger aspect ratio to avoid buckling.Universiti Tenaga Nasional, Malaysi

    The Ethics Of Cyberveillance In A Global Context

    Get PDF
    Whether one calls it “cyberveillance,” “cybermonitoring,” “cybersnooping,” or “cyberspying,” one thing is clear, the computer activities of employees are increasingly being monitored by their companies. Some reports suggest that up to 17% of the Fortune 1,000 companies now utilize some form of computer monitoring software and the predictions are that this figure will jump to 80% very soon. Such software allows an employer to monitor virtually every message sent, website visited and key stroked. Given the global reach of many of these large firms, there are at least two major concerns that need to be addressed. First, what are the ethical implications of this practice? Given that 12% of all firms report that they do not notify their employees of their monitoring activities, are employees being treated fairly? And second, in what ways are local customs, mores and values in various parts of the world being violated or ignored? Like it or not, we are awash in what various popular writers have termed “cyberveillance,” “cybermonitoring,” “cybersnooping,” or “cyberspying.” Simply put, employees’ use of the Internet and email today are increasingly being monitored by their companies. What seems to be missing in this rush to monitor are the ethical implications of doing so, which are significantly exacerbated in multinational firms. In order to understand how such actions are likely to be seen from a variety of multinational perspectives, we first developed a case involving a multinational company contemplating cybermonitoring and then we queried a group of international scholars, asking them to first approach managers in their region for reactions to the case, and then to provide a summary and synthesis of as to how such actions would be received in their respective parts of the world. Finally, we conclude by presenting a reasoned analysis regarding the general ethical questions involved.Before you read this analysis, we invite you to first read the case below and think about your own reactions. This is a hypothetical case involving composite information from the popular press involving a multinational bank. The bank is trying to decide if it should purchase and utilize monitoring software

    Synthesis of new hybrid quinazoline compounds as antiproliferative agents for breast and colon cancer treatment

    Get PDF
    Purpose: To evaluate newly synthesized fuoryl quinazoline derivatives for antitumor efficacy.Methods: Fuoryl quinazoline derivatives were synthesized and the structures of the synthesized compounds were characterized using standard techniques. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) technique was used to assess the anti-proliferative properties of the synthesized derivatives in vitro.Results: All quinazoline compounds displayed cytotoxic activity against breast and colon cancer cell lines to varying degrees. Compound IXa with acetohydrazide moiety was the most effective on MCF7 and HCT116 cell lines, with half-maximal inhibitory concentration (IC50) values of 16.70 and 12.54 μM, respectively.Conclusion: N'-benzylidene-2-((2-(furan-2-yl) quinazolin-4-yl) oxy) acetohydrazide IXa showed the strongest anti-proliferative activity against MCF-7 and HCT116 human cancer cell lines

    Mapping curie point depth of the west African Craton from satellite magnetic data and its implication for diamond exploration

    Get PDF
    The main objective of this work is to map the Curie depth of the West African Craton (WAC) using satellite magnetic data with the aim to provide first order evaluation, within this vast territory, for the spatial association between Curie-depth surface and known kimberlite locations. Taking into account Clifford's rule, the first and foremost exploration guideline for diamond exploration is the existence of a sufficiently thick lithosphere that expected to have a low surface heat flow. The Curie depth is closely related to the surface heat-flow conditions and lithosphere thickness. In actual fact, the only few regions that have sufficient density of surface heat flow measurements corroborate the association of these conditions with the diamond resources. To better explore in an efficient way the spatial relationship between the Curie depth and known diamondiferous primary sources within the WAC, we used GIS-based weights of evidence method to provide a quantitative analysi

    Novel Framework for Hidden Data in the Image Page within Executable File Using Computation between Advanced Encryption Standard and Distortion Techniques

    Full text link
    The hurried development of multimedia and internet allows for wide distribution of digital media data. It becomes much easier to edit, modify and duplicate digital information. In additional, digital document is also easy to copy and distribute, therefore it may face many threats. It became necessary to find an appropriate protection due to the significance, accuracy and sensitivity of the information. Furthermore, there is no formal method to be followed to discover a hidden data. In this paper, a new information hiding framework is presented.The proposed framework aim is implementation of framework computation between advance encryption standard (AES) and distortion technique (DT) which embeds information in image page within executable file (EXE file) to find a secure solution to cover file without change the size of cover file. The framework includes two main functions; first is the hiding of the information in the image page of EXE file, through the execution of four process (specify the cover file, specify the information file, encryption of the information, and hiding the information) and the second function is the extraction of the hiding information through three process (specify the stego file, extract the information, and decryption of the information).Comment: 6 Pages IEEE Format, International Journal of Computer Science and Information Security, IJCSIS 2009, ISSN 1947 5500, Impact Factor 0.42

    State-of-the-art application of artificial neural network in digital watermarking and the way forward

    Get PDF
    Several high-ranking watermarking schemes using neural networks have been proposed in order to make the watermark stronger to resist attacks.The ability of Artificial Neural Network, ANN to learn, do mapping, classify, and adapt has increased the interest of researcher in application of different types ANN in watermarking.In this paper, ANN based approached have been categorized based on their application to different components of watermarking such as; capacity estimate, watermark embedding, recovery of watermark and error rate detection. We propose a new component of water marking, Secure Region, SR in which, ANN can be used to identify such region within the estimated capacity. Hence an attack-proof watermarking system can be achieved

    Rickettsial infection in hospitalised patients in central Tunisia: report of 119 cases

    Get PDF

    Improvement of Synchronous Machine Dynamic Characteristics via Neural Network Based Controllers

    Get PDF
    This paper presents Simulation and experimental study aimed at investigating the effectiveness of an adaptive artificial neural network stabilizer on enhancing the damping torque of a synchronous generator. For this purpose, a power system comprising a synchronous generator feeding a large power system through a short tie line is considered. The proposed adaptive neuro-control system consists of two multi-layered feed forward neural networks, which work as a plant model identifier and a controller. It generates supplementary control signals to be utilized by conventional controllers. The details of the interfacing circuits, sensors and transducers, which have been designed and built for use in tests, are presented. The synchronous generator is tested to investigate the effect of tuning a Power System Stabilizer (PSS) on its dynamic stability. The obtained simulation and experimental results verify the basic theoretical concepts

    Comparative analysis of the efficacy of astigmatic correction after wavefront-guided and wavefront-optimized LASIK in low and moderate myopic eyes

    Get PDF
    AIM: To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis (LASIK) in eyes with myopic astigmatism using wavefront-guided (WFG) and wavefront-optimized (WFO) ablation profiles. METHODS: Prospective study included 221 eyes undergoing LASIK: 99 and 122 eyes with low and moderate myopic astigmatism (low and moderate myopia groups). Two subgroups were differentiated in each group according to the ablation profile: WFG subgroup, 109 eyes (45/64, low/moderate myopia groups) treated using the Advanced CustomVue platform (Abbott Medical Optics Inc.), and WFO subgroup, 112 eyes (54/58, low/moderate myopia groups) treated using the EX-500 platform (Alcon). Clinical outcomes were evaluated during a 6-month follow-up, including a vector analysis of astigmatic changes. RESULTS: Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group (P≤0.041). Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups (P≤0.003). In moderate myopia group, a higher percentage of eyes with a postoperative cylinder ≤0.25 D was found in the WFG subgroup (90.6% vs 65.5%, P=0.002). In low and moderate myopia groups, the difference vector was significantly higher in the WFO subgroup compared to WFG (P<0.001). In moderate myopia group, the magnitude (P=0.008) and angle of error (P<0.001) were also significantly higher in the WFO subgroup. Significantly less induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups (P≤0.006). CONCLUSION: A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.Partially supported by a grant from Abbott Medical Optics
    corecore