1,264 research outputs found

    Electrical and optical properties of carbon nanotube intra-connects and conductive polymers

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    Growth of individual carbon nanotube (CNT) intra-connects (bridges) between two prefabricated electrodes is a great challenge and a pre-requisite to the development of single electron devices. In this thesis, CNT intra-connects were fabricated and studied. Later on, the intra-connects were deposited with electrically conductive polymer (ECP) in the realization of CNT/ECP hybrids. The process started by realizing two electrodes with sharp end on a silicon wafer using e-beam lithography. The intra-connects were then grown by use of chemical vapor deposition (CVD) technique. The intra-connects were later electroplated by various conductive polymers. The morphology, electrical conductivity of these intra-connects as well as their Raman spectroscopy signatures were studied. Scanning electron microscopy (SEM) was also employed. The CNT intra-connects were well-aligned from tip to tip. Their Raman spectra indicated the existence of CNT channels between metal tips and nowhere else on the wafer. Enhancement of photoconductance has been shown to correlate with a novel negative differential resistance (NDR) effect. Electroplated intraconnects exhibited unique properties both for multi-walled and single-walled carbon nanotube channels

    Smartening the Environment using Wireless Sensor Networks in a Developing Country

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    The miniaturization process of various sensing devices has become a reality by enormous research and advancements accomplished in Micro Electro-Mechanical Systems (MEMS) and Very Large Scale Integration (VLSI) lithography. Regardless of such extensive efforts in optimizing the hardware, algorithm, and protocols for networking, there still remains a lot of scope to explore how these innovations can all be tied together to design Wireless Sensor Networks (WSN) for smartening the surrounding environment for some practical purposes. In this paper we explore the prospects of wireless sensor networks and propose a design level framework for developing a smart environment using WSNs, which could be beneficial for a developing country like Bangladesh. In connection to this, we also discuss the major aspects of wireless sensor networks.Comment: 5 page

    Identification of a potential pathway of the exotic black weevil (Coleoptera: Curculionidae) in South Korea

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    The black weevil, Aclees taiwanensis Kôno (Coleoptera: Curculionidae), is one of the primary pests of fig trees in southeastern Asia and southern Europe. Thought to be of subtropical and tropical Asian origin, including China, the weevil was first found in southern areas of South Korea in July 2020. Subsequently, it was found in the following five cities: Haenam, Hampyeong, Jindo, Sinan, and Tongyeong (RDA 2020). Attempts to trace a possible pathway for the exotic black weevil suggested that this species probably followed pathways of illegal importation of infested plants from Taiwan and was unintentionally introduced into South Korea based on analysis of a Pest Information System (PIS) database, a phylogenetic analysis of mitochondrial cytochrome c oxidase subunit I gene (COI) sequences data, and interviews with fig growers. In addition, this exotic weevil could expand to other regions of South Korea since proper control methods for this weevil pest have not yet been developed and some fig trees are cultivated using eco-friendly farming practices. Therefore, constant monitoring will be required for the invasive alien weevil species which seriously damages the trunk of fig trees

    Towards developing smart environment using wireless sensor and ad hoc networks

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    The miniaturization process of various sensing devices has become a reality by enormous research and advancements accomplished in MEMS (Micro Electro-Mechanical Systems) and VLSI (Very Large Scale Integration) lithography. With the advancements of such optimization techniques for hardware, algorithms, and protocols for networking, various wireless technologies have also emerged. The attractive features of these modern technologies have attracted many researchers to work on the design, application and utilization of systems benefited by these high-tech equipments. As a consequence, the idea of smart environment has been come into vision. The focus of this paper is to propose a framework for developing a smart environment aided with the wireless technologies which not only aims at smartening the surrounding environment but also could facilitate the use of a number of smart systems

    Estimation of utility weights for human papilloma virus-related health states according to disease severity

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    Scenarios for the different HPV-related health states. (DOCX 38 kb

    When sex doesn’t sell to men: Mortality salience, disgust and the appeal of products and advertisements featuring sexualized women

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    Although men typically hold favorable views of advertisements featuring female sexuality, from a Terror Management Theory perspective, this should be less the case when thoughts of human mortality are salient. Two experiments conducted in South Korea supported this hypothesis across a variety of products (e.g., perfume and vodka). Men became more negative towards advertisements featuring female sexuality, and had reduced purchase intentions for those products, after thinking about their own mortality. Study 2 found that these effects were mediated by heightened disgust. Mortality thoughts did not impact women in either study. These findings uniquely demonstrate that thoughts of death interact with female sex-appeal to influence men’s consumer choices, and that disgust mediates these processes. Implications for the role of emotion, and cultural differences, in terror management, for attitudes toward female sexuality, and for marketing strategies are discussed

    Minimax Approximation of Sign Function by Composite Polynomial for Homomorphic Comparison

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    The comparison operation for two numbers is one of the most commonly used operations in several applications, including deep learning. Several studies have been conducted to efficiently evaluate the comparison operation in homomorphic encryption schemes, termed homomorphic comparison operation. Recently, Cheon et al. (Asiacrypt 2020) proposed new comparison methods that approximate the sign function using composite polynomial in homomorphic encryption and proved that these methods have optimal asymptotic complexity. In this paper, we propose a practically optimal method that approximates the sign function by using compositions of minimax approximate polynomials. It is proved that this approximation method is optimal with respect to depth consumption and the number of non-scalar multiplications. In addition, a polynomial-time algorithm that determines the optimal compositions of minimax approximate polynomials for the proposed homomorphic comparison operation is proposed by using dynamic programming. The numerical analysis demonstrates that the proposed homomorphic comparison operation reduces running time by approximately 45\% (resp. 41\%) on average, compared with the previous algorithm if running time (resp. depth consumption) is to be minimized. In addition, when NN is 2172^{17}, and the precision parameter α\alpha is 20, the previous algorithm does not achieve 128-bit security, while the proposed algorithm achieves 128-bit security due to small depth consumption
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