Memoryless nonlinear response: A simple mechanism for the 1/f noise

Discovering the mechanism underlying the ubiquity of $"1/f^{\alpha}"$ noise has been a long--standing problem. The wide range of systems in which the fluctuations show the implied long--time correlations suggests the existence of some simple and general mechanism that is independent of the details of any specific system. We argue here that a {\it memoryless nonlinear response} suffices to explain the observed non--trivial values of $\alpha$: a random input noisy signal $S(t)$ with a power spectrum varying as $1/f^{\alpha'}$, when fed to an element with such a response function $R$ gives an output $R(S(t))$ that can have a power spectrum $1/f^{\alpha}$ with $\alpha < \alpha'$. As an illustrative example, we show that an input Brownian noise ($\alpha'=2$) acting on a device with a sigmoidal response function R(S)= \sgn(S)|S|^x, with $x<1$, produces an output with $\alpha = 3/2 +x$, for $0 \leq x \leq 1/2$. Our discussion is easily extended to more general types of input noise as well as more general response functions.Comment: 5 pages, 5 figure

Biointensive integrated management of Lipaphis erysimi Kalt. (Homoptera: Aphididae) in Brassica spp.

Field experiment was conducted at Regional Research station, Samargopalpur, Rohtak (Haryana) during Rabi season of the year 2015-2016 to evaluate bioefficacy of various treatments against mustard aphid, Lipaphis-erysimi on Indian mustard. Treatments were: T1–Verticillium lecanii @ 108 CS/ml, T2–Beauveria bassiana @ 108 CS/ml, T3 - Neem seed kernel extract @ 5%, T4 - Neem seed methanol extract @ 5%, T5 - V. lecanii @ 108 CS/ml + Clipping of infested twigs, T6 - B. bassiana @ 108 CS/ml + Clipping of infested twigs, T7 - NSKE @ 5% + Clipping of infested twigs, T8 - V. lecanii @ 108 CS/ml + NSKE @ 5%, T9 - B. bassiana @ 108 CS/ml + NSKE @ 5%, T10 - Dime-thoate 30EC @ 250 ml/acre. Dimethoate was found to be most effective in reducing the aphid population (95.03 %) followed by V. lecanii @ 108 CS/ml + NSKE @ 5% (88.52 %), NSKE @ 5% + Clipping of infested twigs (87.77 %) and B. bassiana @ 108 CS/ml + NSKE @5% (86.91 %) after ten days of spray. The highest seed yield was recorded in treatment dimethoate 30EC (1702 kg/ha) followed by V.lecanii @ 108 CS/ml +NSKE @ 5% (1635 kg/ha), NSKE @ 5% + Clipping of infested twigs (1626 kg/ha) and B.bassiana @ 108 CS/ml + NSKE @ 5% (1617 kg/ha). Dimethoate was found to be highly cost effective with highest cost benefit ratio (1:14.92) followed by NSKE @ 5% + clipping of infested twigs (1:13.81) and NSKE @ 5% (1:11.41)

Assessment of trends in rainfall-runoff events in a mountain basin: analysis of the influence of initial conditions by means of a hydrological model and GIS

openDespite the expectation that increases in rainfall with climatic change will result in increases in pluvial flooding, there is more historical evidence for decreases in flood magnitude. The small basin of La Vizza, in the Eastern Italian Alps, provides a clear example for this type of trend divergence. In this basin, flood magnitudes are decreasing, despite increasing rainfall extremes. In this thesis we investigate how changes in soil moisture and snow water equivalent play a role in controlling the above divergence. Using catchment average precipitation and temperature, and a continuous hydrological model able to specify soil moisture and snow water equivalent at the start of each rainfall-runoff events, we aim to better understand the relative role of the two drivers in controlling the trends in runoff events (both volumes and peaks). With this overarching objective, the thesis has the following specific objectives: i) Quantify the diverging trends in annual maxima of rainfall and runoff events for the study basin; ii) Quantifying the snow cover area and snow water equivalent by means of the TOPMELT model and validating it by using MODIS satellite images; iii) Quantify the trends for event-generating precipitation, antecedent soil moisture, and antecedent snow water equivalent and assess their role in controlling the trend in runoff events. The monotonic trends will be assessed using the non-parametric Mann-Kendall test and the trend slopes will be determined by Sen’s slope method. The findings of this research will have significant implications for understanding the role of the underlaying hydrological factors such as soil moisture and snow water equivalent controlling the trends in rainfall-runoff events in other similar mountain basin.Despite the expectation that increases in rainfall with climatic change will result in increases in pluvial flooding, there is more historical evidence for decreases in flood magnitude. The small basin of La Vizza, in the Eastern Italian Alps, provides a clear example for this type of trend divergence. In this basin, flood magnitudes are decreasing, despite increasing rainfall extremes. In this thesis we investigate how changes in soil moisture and snow water equivalent play a role in controlling the above divergence. Using catchment average precipitation and temperature, and a continuous hydrological model able to specify soil moisture and snow water equivalent at the start of each rainfall-runoff events, we aim to better understand the relative role of the two drivers in controlling the trends in runoff events (both volumes and peaks). With this overarching objective, the thesis has the following specific objectives: i) Quantify the diverging trends in annual maxima of rainfall and runoff events for the study basin; ii) Quantifying the snow cover area and snow water equivalent by means of the TOPMELT model and validating it by using MODIS satellite images; iii) Quantify the trends for event-generating precipitation, antecedent soil moisture, and antecedent snow water equivalent and assess their role in controlling the trend in runoff events. The monotonic trends will be assessed using the non-parametric Mann-Kendall test and the trend slopes will be determined by Sen’s slope method. The findings of this research will have significant implications for understanding the role of the underlaying hydrological factors such as soil moisture and snow water equivalent controlling the trends in rainfall-runoff events in other similar mountain basin

Phytoremediation of Hazardous Radioactive Wastes

Phytoremediation technology incorporates living plants for in situ remediation of contaminated soils, sediments, tailings and groundwater. These practices integrates the removal, or degradation of toxic wastes that is capable of cleaning up an area with low to moderate levels of contamination. Phytoremediation has been studied widely for metals, pesticides, solvents, explosives, crude oil, etc. These studies and research are advanced, especially in small-scale operations. Phytoremediation has been successfully tested to decontamination of radioactive sites. The chapter initiates with possible remediation methods used for radioactive wastes where we will discuss types and nature of radioisotope contamination. Then we discuss discusses the classifications of phytoremediation techniques to treat radioactive contaminated waste. Phytoremediation performance depends on numerous factors such as soil composition, level of toxicity, suitable plant species, etc. Conversely, phytoremediation prospects low cost, practical and ecologically viable approach for low-level radiation waste clean-up

Generic Home Automation System Using IoT Gateway Based on Wi-Fi and ant+ Sensor Network

This research article explores the use of internet of things (IoT) technology in home automation, including cloud computing and sensor networks to improve quality of life, and the increasing affordability through mobile connectivity. In this proposed smart home system, our main objective is to build a home automation system for the common consumer, which can help him to use home appliances with confidence and control at a low cost. The paper describes the building of an IoT gateway using the ANT multi-hop wireless network protocol and the Wi-Fi protocol, specifically utilizing the nRF24L01 and Esp8266 chips. Various sensor nodes, such as a water tank level sensor, human presence sensor, smart LED door sensor, and smart switch, will be integrated into the system. The main goal of the research is to develop an affordable solution for smart home technology for everyday consumers

Evaluation of flexible SPA based LPDC decoder using hardware friendly approximation methods

Due to computation-intensive nature of LDPC decoders, a lot of research is going towards efficient implementation of their original algorithm (SPA). As "Min-Sum" approximation is basically an overestimation of SPA, this thesis investigates more accurate, yet area efficient, approximations of SPA, to select an optimum one. In a general comparison between main approximation methods (e.g. LUT, PWL, CRI), PWL showed the most area-efficiency. Studying different mathematical formats of SPA, Soft-XOR based format with forward-backward scheme was chosen for hard- ware implementation. Its core function (Soft-XOR) was implemented with CRI approximation, which achieved the highest efficiency, compare to other approxi- mations. Using this core function, a flexible, pipe-lined, Soft-XOR based CNU (the computational unit of LDPC decoders) with forward-backward architecture was developed in 18nm CMOS. The implemented CNU’s area and speed can eas- ily be changed in instantiation. A SPA decoder based on the developed CNU was estimated to have an area of 1.6M as equivalent gate count and a throughput of 10Gb/s, with a frequency of 1.25GHz and for 10 iterations. The decoder uses IEEE 802.11n Wi-Fi standard with flooding schedule. The BER/SNR loss, com- pare to floating-point SPA, is 0.3dB for 10 iterations and less than 0.1dB for 20 iterations.You have to get lost before you can be found, a quote by Jeff Rasley goes very well for Low Density Parity Check (LDPC) codes. First invented by Gallager in 1962 but kind of lost during the journey of evolution of telecommunication networks because of their high complexity and demanding computations, which technology was not so advanced to handle, at that time. However, during late 1990s, success of turbo codes invoked the re-discovery of Low Density Parity Check (LDPC) codes. Recently it has attracted tremendous research interest among the scientific com- munity, as today’s technology is advanced enough and to make LDPC decoders completely commercial. In a wireless network, the information is not just sim- ply sent, but first encoded. In a sense, all the transmitted bits are tied together, according to some mathematical rules. Therefore, if noise destructs parts of the information while traveling, the LDPC decoder at the receiver side, can automat- ically detect and retrieve those parts, based on the other parts. Here, our main focus is on the decoder. For actual hardware implementation of the decoder, some level of approximation of the ideal algorithm is always necessary, which reduces the accuracy depending on the approximation. Ericsson is developing the next-generation wireless network for 5G, and already possesses the "Min-Sum" approximation of the LDPC decoder. As the current requirements demand more accurate decoders, the goal of this thesis is to evalu- ate a more accurate but more costly version of the LDPC decoder, as well as its flexibility. Thus, several candidates were selected and evaluated based on their complexity, cost, and their accuracy towards error correction. After performing several trade-offs, an approximation method is chosen and the corresponding cost is derived. With this acquired data, a trade-off between accuracy and cost can be made, depending on the application

Avian Community Composition in and around Mandothi Wetlands, Haryana, India

Comprising an area of approximately 1000 acres, Mandothi wetlands are located in Bahadurgarh tehsil of Jhajjar district of Haryana, India and provide an important wintering ground for migratory birds. From December 2021 to June 2022, fortnightly surveys were made to document the avian community composition of the study area in Mandothi wetlands using point-count and line-transect methods. A total of 124 species belonging to 90 genera, 38 families, and 15 orders were recorded. Passeriformes was the most represented avian order, with 38 species and 15 families. Feeding guild analysis revealed that carnivore was the most dominant feeding guild in the study area. Of the recorded 124 avian species, 73 species were residents, 44 species were winter migrants and 7 species were summer migrants. As per the IUCN Red List 8 species were classified as Near Threatened (Ferruginous Duck Aythya nyroca, Black-tailed Godwit Limosa limosa, Eurasian Curlew Numenius arquata, Painted Stork Mycteria leucocephala, Woolly-necked Stork Ciconia episcopus, Black-necked Stork Ephippiorhynchus asiaticus, Black-headed Ibis Threskiornis melanocephalus, Darter Anhinga melanogaster) and 2 species were classified as Vulnerable (Sarus Crane Antigone antigone and River Tern Sterna aurantia). In addition to the present survey, 17 species were also reported from secondary sources, resulting in a checklist of 141 bird species. The occurrence of migratory and species of global conservation priority documents the importance of this wetland as a potential habitat for avifauna in Haryana

A Review on OFDMA and MU-MIMO MAC Protocols for upcoming IEEE Standard 802.11ax

IEEE introduced a new standard IEEE 802.11ax for the next generation WLANs.As we know,the current throughput is very low because of the current Media Access Control(MAC) in present wireless area networks.So,the concept of Orthogonal Frequency Multiple Access(OFDMA) to facilitate multi user access is introduced.The main challenges of adopting OFDMA areoverhead reduction and synchronization.To meet these challenges this paper revised an OFDMA based OMAX protocol.And due to various various bandwidth consuming applications and devices today’s WLANs have become stressed and low at throughput.To handle this problem MU MIMO is used to improve the performance of WLANs.This paper surveys uplink/downlink mutli user MAC protocols for MIMO enabled devices.It also identifies the key requirements of MAC protocol design