TCP CERL+: revisiting TCP congestion control in wireless networks with random loss

Wireless Networks - In this paper, we analyze the performance of wireless networks subject to random loss. In this regard, we revisit our TCP Congestion Control Enhancement for Random Loss (CERL)...     

Fuzzy Learning of Talbot Effect Guides Optimal Mask Design for Proximity Field Nanopatterning Lithography

Processing methods used in photonics and nanotechnology possess many limitations restricting their application areas such as high cost, inability to produce fine details, problems with scalability, and long processing time. Proximity field nanopatterning is a lithography method which surpasses these limitations. By using interference patterns produced by a two-dimensional phase mask, the technique is able to generate a submicron detailed exposure on a millimeter-size slab of light sensitive photopolymer, which is then developed like a photographic plate to reveal three-dimensional interference patterns from the phase mask. While it is possible to use simulations to obtain the interference patterns produced by a phase mask, realizing the mask dimensions necessary for producing a desired interference pattern is analytically challenging due to the intricacies of light interactions involved in producing the final interference pattern. An alternative method is to iteratively optimize the phase mask until the interference patterns obtained converge to the desired pattern. However, depending on the optimization technique used, one either risks a significant probability of failure or requires a prohibitive number of iterations. We argue that an optimization technique that is to take advantage of the physics of the problem using machine learning methods (here fuzzy learning) can lead to competent mask design. This technique is described in this letter.     

Pyranoxanthones from Calophyllum Inophyllum

Phytochemical investigation of the stem bark of Calophyllum inophyllum resulted in the isolation of a new dipyrenoxanthone, calophinone ( 1 ), together with four related xanthones ( 2–5 ). Identification of the isolated compounds was achieved through intensive studies of their spectral data, especially 2D NMR.     

Equilibrium Studies of Binary and Ternary Complexes Involving Tricine and Some Selected α-Amino Acids

Summary. The formation equilibria for the binary complexes of Co^II, Ni^II, Cu^II, Zn^II, Cd^II, Mn^II, Pb^II, Th^IV, UO₂^II, and Ce^III with tricine and for the ternary complexes involving some -amino acids (glycine, -alanine, proline, serine, asparagine, and aspartic acid) were investigated using pH-metric technique. The formation of binary and ternary complexes was inferred from the pH-metric titration curves. It was deduced that tricine acts as a primary ligand in the ternary complexes involving the monocarboxylic amino acids (glycine, -alanine, proline, serine, and asparagine), whereas it behaves as a secondary ligand in the ternary systems containing the dicarboxylic aspartic acid. The ternary complex formation was found to take place in a stepwise manner. The stability constants of the complexes formed in aqueous solutions were determined potentiometrically under the experimental conditions (t=25°C, I=0.1moldm^–3 NaNO₃). The order of stability of the ternary complexes in terms of the nature of the amino acids is investigated and discussed. The values of log K for the ternary complexes have been evaluated and discussed. Evaluation of the effects of ionic strength and temperature of the medium on the stability of the ternary system M^II-tricine--alanine (M^II=Co^II, Ni^II, and Cu^II) has been studied. The thermodynamic parameters were calculated and discussed.     

Antiplatelet and anti-HIV constituents from Euchresta formosana

Phytochemical investigation of the methanol extract of Euchresta formosana resulted in the isolation of thirty-four compounds. Compounds 1, 3-12, 15, 27, 29 and 32-24 were isolated from this species for the first time. These compounds were identified by spectral analyses and tested for antiplatelet aggregation and anti-HIV activities. Among these compounds, tectorigenin (1), 3',4',5-trihydroxyisoflavone (3), and euchretin F (19) were the most effective antiplatelet aggregation compounds; they inhibited both AA- (arachidonic acid) and collagen-induced platelet aggregation. Meanwhile, flemiphyllin (B), quercetin (13), euchretin M (23), and formosanatin C (26) inhibited HIV replication in H9 lymphocyte cells.     

Trace measurements of rhodium by adsorptive stripping voltammetry

A sensitive stripping voltammetric procedure for quantifying rhodium is described. The complex of rhodium with chloride ions is adsorbed on the hanging mercury drop electrode, and the reduction current of the accumulated complex is measured during a negative-going scan. Cyclic voltammetry is used to characterize the interfacial and redox behaviors. The effect of pH, chloride concentration, accumulation potential and other variables is discussed. The detection limit is 1 x 10(-8)M ( approximately 1 ng/ml) with 5-min accumulation. A linear current-concentration relationship is observed up to 7 x 10(-7)M and the relative standard deviation (at the 2 x 10(-7)M level) is 3.0%. Possible interferences by co-existing metals are investigated.     

O. Carboxyphenylhydrazoethylacetoacetate as an Analytical Reagent for the Determination of Cu(II) and Co(II) in Complex Materials

An extraction‐spectrophotometric method for the determination of trace amounts of copper and cobalt based on their extraction into n‐pentanol with 0. carboxyphenylhydrazoethylacetoacetate (O.CPHEAA) was per formed. Copper was extracted from pH 6.0 – 8.0 and ionic strength 0.5 M – KCl. The maximum absorption of the extracted Cu(II) ‐ O.CPHEAA complex (1:1 & 1:2 species) occurs at 415 nm. The proposed method succeeded in as saying a concentration of 3–63 μg per 10 mL of n‐pentanol (? = 1.25 × 10⁴L mol^?1 cm^?1). The method failed to ex tract cobalt ion into various organic sol vents over a pH range of 2–11. The suggested method is highly selective and sensitive according to a wide scheme of interference studied. Copper in some plant samples was accurately estimated using the suggested method. The obtained results and the results of the AAS method were consistent. The reproducibility test shows a relative standard deviation of 1%. Sandell sensitivity for A = 0.001 is 5 × 10^?3 μg cm^?2.     

Tasumatrols P – T,Five New Taxoids from Taxus sumatrana

The phytochemical investigation of the more polar fractions from the leaves and twigs of Taxus sumatrana (Taxaceae) afforded five new taxane diterpene esters, tasumatrols P–T ( 1 – 5 ) possessing an 11(15→1),11(10→9)‐diabeotaxane skeleton. Compounds 1, 4 , and 5 contain an α‐hydroxy group at C(14), while 3 has no OH group at either C(13) or C(14). Compound 2 is a natural 4,5‐acetonide derivative, while 4 has an unusual spiro‐connected 2‐hydroxy‐2‐phenyl‐1,3‐dioxolane ring. Ten known taxoids, were also isolated in the course of the chromatographic fractionation. Five additional new O‐acetyl derivatives 3a, 4a, 4b, 5a , and 5b were prepared from the taxanes 3 – 5 . The structures of all new compounds were established on the basis of their spectroscopic analyses. Compound 1 showed mild cytotoxic activity against human Hela and Daoy tumor cells.     

Detection of Abnormal Activities from Various Signals Based on Statistical Analysis

We perceive big data with massive datasets of complex and variegated structures in the modern era. Such attributes formulate hindrances while analyzing and storing the data to generate apt aftermaths. Privacy and security are the colossal perturb in the domain space of extensive data analysis. In this paper, our foremost priority is the computing technologies that focus on big data, IoT (Internet of Things), Cloud Computing, Blockchain, and fog computing. Among these, Cloud Computing follows the role of providing on-demand services to their customers by optimizing the cost factor. AWS, Azure, Google Cloud are the major cloud providers today. Fog computing offers new insights into the extension of cloud computing systems by procuring services to the edges of the network. In collaboration with multiple technologies, the Internet of Things takes this into effect, which solves the labyrinth of dealing with advanced services considering its significance in varied application domains. The Blockchain is a dataset that entertains many applications ranging from the fields of crypto-currency to smart contracts. The prospect of this research paper is to present the critical analysis and review it under the umbrella of existing extensive data systems. In this paper, we attend to critics' reviews and address the existing threats to the security of extensive data systems. Moreover, we scrutinize the security attacks on computing systems based upon Cloud, Blockchain, IoT, and fog. This paper lucidly illustrates the different threat behaviour and their impacts on complementary computational technologies. The authors have mooted a precise analysis of cloud-based technologies and discussed their defense mechanism and the security issues of mobile healthcare.

     

Electroanalysis at modified carbon-paste electrodes containing natural ionic polysaccharides

The strong affinity of natural ionic polysaccharides for certain metal ions is exploited in the design of a new class of voltammetric sensing devices. In particular, carbon-paste electrodes containing pectic and alginic acids are used for the nonelectrolytic collection and subsequent voltammetric determination of copper and lead, respectively. Cyclic and differential pulse voltammetry are used to quantify the accumulated ions. The response is characterized with respect to modifier loading, preconcentration period, metal concentration, reproducibility, possible interferences and other variables. Titrimetric experiments illustrate the potential of polysaccharide electrodes for speciation work. Preliminary data are also given for analogous measurements of copper at heparin-modified electrodes. Detection limits are 1 mug/ml and the relative standard deviation is 4.8%.