20 research outputs found

    Fibonary Spray and Wait Routing in Delay Tolerant Networks

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    Although there has been a tremendous rise in places being connected through the Internet or any other network protocol, there still lie areas, which remain out of reach due to various reasons. For all such places the answer is a Delay Tolerant Network (DTN). A DTN is such a network where there is no fixed or predefined route for messages and no such guarantee whatsoever of all messages being correctly routed. DTN can be considered as a superset of networks wherein other networks such as adhoc, mobile, vehicular etc. form the subset. Therefore routing in DTN is a very chancy affair where one has to maximize on the present network scenarios to get any fruitful result other than depending on past information. Also protocols here need to be less complex and not increase the already high nodal overhead. In this paper we propose a new approach, the Fibonary Spray and Wait, which does exactly this. It forwards copies of a message in a modified Binary Spray and Wait manner so that it performs well even in non independent and identically distributed node structure. We have supported our statements with mathematical as well as simulation analysis

    Climate-Smart Agriculture in Nepal: Champion technologies and their pathways for scaling up

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    This policy brief synthesises key findings and recommendations for decision-making under uncertainty in the agriculture sector in Nepal. This brief highlights the methodologies used for selection of champion climate-smart agriculture (CSA) practices for different agro-ecological regions of Nepal and recommendations for scaling up the champion CSA technologies and practices in Nepal. Adaptation to climate change in the agricultural sector and allied sectors is a major current and future challenge for Nepal. The majority of the population is still dependent on highly climate-sensitive agriculture. In recent years, long drought spells during the monsoon season and increased temperatures and unseasonal heavy rains during winter have caused serious distress to agriculture-dependent communities in many locations. If the Sustainable Development Goals (SDGs) of ending poverty, achieving food security and promoting sustainable agriculture are to be realised, climate change adaptation interventions need to be implemented in earnest

    TREND ANALYSIS OF AREA, PRODUCTION, PRODUCTIVITY, AND SUPPLY OF POTATO IN SINDHULI DISTRICT AND NEPAL: A COMPARATIVE STUDY

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    The study; conducted from January, 2020 to June, 2020; focuses on the comparative study of the area, production, and productivity trend of potatoes over 50 years in Sindhuli district and Nepal and a brief overview on quantity supply to the Kalimati fruits and vegetable market. The time-series data from 1968/69 to 2017/18 of Sindhuli and Nepal along with 6 years supply data (2013/14-2018/19) from different districts to Kalimati market were collected from reliable sources (Ministry of Agriculture and Livestock Development and Kalimati Fruits and Vegetable Market Development Board) and analysis was done using Microsoft Excel. Between 1968/69 and 2017/18, the area under potato cultivation in Nepal and Sindhuli has changed by 573 percent and -46 percent respectively while production increased by 907.6 percent in Nepal and 46 percent in Sindhuli. After 1982 dramatic shift in production was observed in Nepal as there was 7 percent of growth rate while in Sindhuli, the production trend highly fluctuates throughout the period. The average yield was 9.75mt/ha and 8.75mt/ha for Nepal and Sindhuli district. Sindhuli district contributes 1.16 percent of Nepalese potato growing area and 0.91 percent of Nepalese potato production. The trend of quantity supply reveals that during 6 years, Indian potato contributes 58 percent of the total amount that came into Kalimati market, while within-country Kavre has the largest share of 19 percent followed by Kathmandu-6 percent and Dolakha-4 percent. However, the trend of quantity supply of potatoes seems highly fluctuating and the Nepalese market is dominated by Indian imports

    Evaluation of Phytochemical, Antioxidant and Antibacterial Activities of Selected Medicinal Plants

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    Medicinal plants are important reservoirs of bioactive compounds that need to be explored systematically. Because of their chemical diversity, natural products provide limitless possibilities for new drug discovery. This study aimed to investigate the biochemical properties of crude extracts from fifteen Nepalese medicinal plants. The total phenolic contents (TPC), total flavonoid contents (TFC), and antioxidant activity were evaluated through a colorimetric approach while the antibacterial activities were studied through the measurement of the zone of inhibition (ZoI) by agar well diffusion method along with minimum inhibitory concentrations (MIC) by broth dilution method. The methanolic extracts of Acacia catechu and Eupoterium adenophorum showed the highest TPC (55.21 ± 11.09 mg GAE/gm) and TFC (10.23 ± 1.07 mg QE/gm) among the studied plant extracts. Acacia catechu showed effective antioxidant properties with an IC50 value of 1.3 μg/mL, followed by extracts of Myrica esculenta, Syzygium cumini, and Mangifera indica. Morus australis exhibited antibacterial activity against Klebsiella pneumoniae (ZoI: 25mm, MIC: 0.012 mg/mL), Staphylococcus aureus ATCC 25923 (ZoI: 22 mm, MIC: 0.012 mg/mL), Pseudomonas aeruginosa (ZoI; 20 mm, MIC: 0.05 mg/mL), and methicillin-resistant Staphylococcus aureus (MRSA) (ZoI: 19 mm, MIC: 0.19 mg/mL). Morus australis extract showed a broad-spectrum antibacterial activity, followed by Eclipta prostrata, and Hypericum cordifolium. Future study is recommended to explore secondary metabolites of those medicinal plants to uncover further clinical efficacy

    Understanding Host Resistance and Pathogen Biology in the Wheat-Fusarium graminearum Pathosystem

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    Fusarium head blight (FHB) is a major challenge in global wheat production. In the United States, the disease is predominantly caused by the fungus Fusarium graminearum. Utilization of FHB-resistant wheat cultivars integrated with other measures such as fungicide application is the most effective approach for the management of this disease. This study aimed to 1) identify novel quantitative trait loci (QTL) for resistance to FHB in a Brazilian spring wheat cultivar ‘Surpresa’ through bi-parental mapping, 2) detect QTL for FHB resistance in a global panel of 233 spring wheat accessions by genome-wide association analysis (GWAS), and 3) localize genomic regions governing traits associated with virulence in Fusarium graminearum. Using phenotypic and genotypic data from 187 recombinant inbred lines derived from the cross between Surpresa and a susceptible spring wheat cultivar ‘Wheaton’, four QTL (Qfhb.ndwp-2AS, Qfhb.ndwp-2AL, Qfhb.ndwp-3B, and Qfhb.ndwp-4D) were mapped on chromosomes 2A, 3B, and 4D of Surpresa, respectively. Qfhb.ndwp-2AS, Qfhb.ndwp-2AL, and Qfhb.ndwp-3B were found to be novel based on physical locations of the markers tightly linked to these QTL. Two significant marker-trait associations (Qfhb.ndwp-3A and Qfhb.ndwp-2BL) were detected by GWAS of 233 spring wheat accessions, which conferred type II and type III FHB resistance and mapped on chromosomes 3A and 2B, respectively. Both QTL were novel based on the physical locations of tightly linked markers. GWAS of virulence and fungicide sensitivity using 183 F. graminearum isolates collected from North Dakota identified two significant marker-trait associations in chromosomes 1 and 3 for virulence, and two for fungicide sensitivity. The genes associated with virulence that were detected in this study were not previously reported. Identification of these novel genes in metabolic pathways of F. graminearum could help to develop new strategies for the management FHB

    Hybrid Energy Systems with Small Modular Reactor Based Nuclear Power Plants and Renewable Energy Sources: Modeling, Operation and Planning Studies

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    The abstract of this item is unavailable due to an embargo

    Operational Resilience of Nuclear-Renewable Integrated-Energy Microgrids

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    The increasing prevalence and severity of wildfires, severe storms, and cyberattacks is driving the introduction of numerous microgrids to improve resilience locally. While distributed energy resources (DERs), such as small-scale wind and solar photovoltaics with storage, will be major components in future microgrids, today, the majority of microgrids are backed up with fossil-fuel-based generators. Small modular reactors (SMRs) can form synergistic mix with DERs due to their ability to provide baseload and flexible power. The heat produced by SMRs can also fulfill the heating needs of microgrid consumers. This paper discusses an operational scheme based on distributed control of flexible power assets to strengthen the operational resilience of SMR-DER integrated-energy microgrids. A framework is developed to assess the operational resilience of SMR-DER microgrids in terms of system adaptive real-power capacity quantified as a response area metric (RAM). Month-long simulation results are shown with a microgrid developed in a modified Institute of Electrical and Electronics Engineers (IEEE)-30 bus system. The RAM values calculated along the operational simulation reflect the system resilience in real time and can be used to supervise the microgrid operation and reactor’s autonomous control

    Design and Evaluation of a Reliable TRNG using Probabilistic Switching Circuits

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    On-chip true random number generator (TRNG) circuits are designed by harnessing physical random variations, such as thermal noise or supply noise, and are ideally expected to generate sequence of random bits with very high bit-entropy and zero correlation. However, increasing variations in the fabrication process and the sensitivity of transistors to operating conditions (e.g., process, voltage and temperature, (PVT)) have significant effect on the bit-entropy of TRNGs designed in deep nanometer technologies. Moreover, the process variation and operating conditions can be exploited by an adversary as effective tools to attack TRNGs. In order to mitigate these issues, we propose a probabilistic approach to design and analyze a TRNG by leveraging a probabilistic switching circuit based design paradigm. The basic component of our proposed TRNG is a probabilistic switch (pswitch). We use probabilistic complementary metal-oxide-semiconductor (PCMOS) inverter as the probabilistic switch in our design. The probabilistic switch is the source of entropy and is modeled as a Beta-Bernoulli process. We simulate our TRNG circuit using Dsch and Microwind simulator using 65 nm65\,nm and 32 nm32\,nm process technology. Results reveal that our proposed TRNG can generate random numbers with bit-entropy in the range [0.998,1][0.998, 1] at data rate of 200200 Mbps. Moreover, simulation results indicates that our proposed TRNG is robust against the temperature, power supply, and fabrication process variations

    Design and Validation of Low-Power Secure and Dependable Elliptic Curve Cryptosystem

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    The elliptic curve cryptosystem (ECC) has been proven to be vulnerable to non-invasive side-channel analysis attacks, such as timing, power, visible light, electromagnetic emanation, and acoustic analysis attacks. In ECC, the scalar multiplication component is considered to be highly susceptible to side-channel attacks (SCAs) because it consumes the most power and leaks the most information. In this work, we design a robust asynchronous circuit for scalar multiplication that is resistant to state-of-the-art timing, power, and fault analysis attacks. We leverage the genetic algorithm with multi-objective fitness function to generate a standard Boolean logic-based combinational circuit for scalar multiplication. We transform this circuit into a multi-threshold dual-spacer dual-rail delay-insensitive logic (MTD3L) circuit. We then design point-addition and point-doubling circuits using the same procedure. Finally, we integrate these components together into a complete secure and dependable ECC processor. We design and validate the ECC processor using Xilinx ISE 14.7 and implement it in a Xilinx Kintex-7 field-programmable gate array (FPGA)

    Design and Validation of Low-Power Secure and Dependable Elliptic Curve Cryptosystem

    No full text
    The elliptic curve cryptosystem (ECC) has been proven to be vulnerable to non-invasive side-channel analysis attacks, such as timing, power, visible light, electromagnetic emanation, and acoustic analysis attacks. In ECC, the scalar multiplication component is considered to be highly susceptible to side-channel attacks (SCAs) because it consumes the most power and leaks the most information. In this work, we design a robust asynchronous circuit for scalar multiplication that is resistant to state-of-the-art timing, power, and fault analysis attacks. We leverage the genetic algorithm with multi-objective fitness function to generate a standard Boolean logic-based combinational circuit for scalar multiplication. We transform this circuit into a multi-threshold dual-spacer dual-rail delay-insensitive logic (MTD3L) circuit. We then design point-addition and point-doubling circuits using the same procedure. Finally, we integrate these components together into a complete secure and dependable ECC processor. We design and validate the ECC processor using Xilinx ISE 14.7 and implement it in a Xilinx Kintex-7 field-programmable gate array (FPGA)
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