Research Directions, Challenges and Issues in Opinion Mining

Rapid growth of Internet and availability of user reviews on the web for any product has provided a need for an effective system to analyze the web reviews. Such reviews are useful to some extent, promising both the customers and product manufacturers. For any popular product, the number of reviews can be in hundreds or even thousands. This creates difficulty for a customer to analyze them and make important decisions on whether to purchase the product or to not. Mining such product reviews or opinions is termed as opinion mining which is broadly classified into two main categories namely facts and opinions. Though there are several approaches for opinion mining, there remains a challenge to decide on the recommendation provided by the system. In this paper, we analyze the basics of opinion mining, challenges, pros & cons of past opinion mining systems and provide some directions for the future research work, focusing on the challenges and issues

Behavior of reinforced higher-strength concrete beams in bending and shear

Call number: LD2668 .T4 CE 1987 N37Master of ScienceCivil Engineerin

Strength and microstructure of mortar with sand substitutes

U radu se razmatra čvrstoća i mikrostruktura morta u kojem se kao zamjena za riječni pijesak (RS) koriste drobljeni pijesak (MS) i granitni prah (GP) u raznim udjelima. Za postizanje maksimalne tlačne čvrstoće i vlačne čvrstoće pri cijepanju, optimalni težinski udio GP u RS iznosi 15 %. Svojstva čvrstoće morta koji sadrži MS bolja su od odgovarajućih svojstava mortova RS i GP, bez obzira na vrijeme njege. Za mortove MS i GP provedena je toplinska analiza, mikrostrukturna analiza i mineraloška analiza, a pritom su korišteni postupci TGA, SEM, XRD i FT-IR.The strength and microstructure of mortars incorporating manufactured sand (MS) and various levels of granite powder (GP) as substitutes for river sand (RS) are considered in the paper. The optimum RS substitution by GP is 15 % by mass for the maximum compressive and splitting tensile strength. Strength properties of mortars containing MS are better when compared to RS and GP mortars, irrespective of the curing period. The thermal analysis, microstructural analysis, and mineralogical analysis are conducted on MS and GP mortars using TGA, SEM, XRD and FT-IR techniques

Rebar properties in sand-substitute mortars after exposure to high temperatures

U ovom se radu istražuje utjecaj zagrijavanja, metoda hlađenja i debljine zaštitnog sloja na ponašanje (čvrstoću i duktilnost) rebraste armature promjera 12 mm ugrađene u mort u kojem je riječni pijesak zamijenjen granitnim prahom i proizvedenim pijeskom, pri čemu debljina zaštitnog sloja iznosi 30 i 50 mm. Na temperaturama iznad 500 °C, toplinsko naprezanje uzrokovalo je nasumično ljuskanje zaštitnog sloja, a vlačna ispitivanja upozorila su na smanjenje čvrstoće i povećanje duktilnosti armature pri hlađenju na zraku, dok je suprotna pojava uočena pri gašenju vodom.This study investigates the effects of fire, cooling methods, and cover thickness, on the behaviour (strength and ductility) of 12-mm diameter rebars embedded in mortars with river sand (RS) substitutes such as granite powder and manufactured sand, with 30 and 50 mm cover thickness. Beyond 500°C, thermal stress induced random spalling of mortar cover, and tension test results showed strength decrement and ductility increment of rebars for air cooling, while the vice versa was observed for water quenching

Silica nanoparticles from coir pith synthesized by acidic sol-gel method improve germination economics

Lignin is a natural biopolymer. A vibrant and rapid process in the synthesis of silica nanoparticles by consuming the lignin as a soft template was carefully studied. The extracted biopolymer from coir pith was employed as capping and stabilizing agents to fabricate the silica nanoparticles (n Si). The synthesized silica nanoparticles (n Si) were characterized by ultraviolet–visible (UV–Vis) spectrophotometry, X-ray diffraction analysis (XRD), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Analysis (EDAX), Dynamic Light Scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FTIR). All the results obtained jointly and independently verified the formation of silica nanoparticles. In addition, EDAX analysis confirmed the high purity of then Si composed only of Si and O, with no other impurities. XRD spectroscopy showed the characteristic diffraction peaks forn Si and confirmed the formation of an amorphous nature. The average size ofn Si obtained is 18 nm. The surface charge and stability ofn Si were analyzed by using the dynamic light scattering (DLS) and thus revealed that then Si samples have a negative charge (−20.3 mV). In addition, the seed germination and the shoot and root formation on Vigna unguiculata were investigated by using then Si. The results revealed that the application ofn Si enhanced the germination in V. unguiculata. However, further research studies must be performed in order to determine the toxic effect of biogenicn Si before mass production and use of agricultural applications. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.1/2018/187DST-FIST fund [SR/FST/LS-1/2018/187

Strength of dapped end beams

Bibliography: p. 113-118

Echo Cancellation For Voice Over Internet Protocol (VOIP) Networks

In this research, a Packet Based Echo Canceller (PBEC) is introduced as a new solution for Echo Cancellation in the VoIP network. The PBEC would receive the packets that come from the gateway and cancel the echo by using the conventional adaptive filter algorithms

GA-DoSLD: Genetic Algorithm Based Denial-of-Sleep Attack Detection in WSN

Denial-of-sleep (DoSL) attack is a special category of denial-of-service attack that prevents the battery powered sensor nodes from going into the sleep mode, thus affecting the network performance. The existing schemes used for the DoSL attack detection do not provide an optimal energy conservation and key pairing operation. Hence, in this paper, an efficient Genetic Algorithm (GA) based denial-of-sleep attack detection (GA-DoSLD) algorithm is suggested for analyzing the misbehaviors of the nodes. The suggested algorithm implements a Modified-RSA (MRSA) algorithm in the base station (BS) for generating and distributing the key pair among the sensor nodes. Before sending/receiving the packets, the sensor nodes determine the optimal route using Ad Hoc On-Demand Distance Vector Routing (AODV) protocol and then ensure the trustworthiness of the relay node using the fitness calculation. The crossover and mutation operations detect and analyze the methods that the attackers use for implementing the attack. On determining an attacker node, the BS broadcasts the blocked information to all the other sensor nodes in the network. Simulation results prove that the suggested algorithm is optimal compared to the existing algorithms such as X-MAC, ZKP, and TE2P schemes

Intracranial dural arteriovenous fistulas: A Review

Dural arteriovenous fistulas are fistulas connecting the branches of dural arteries to dural veins or a venous sinus. Digital subtraction angiography remains the gold standard for diagnosing these fistulas. Endovascular treatment is one of the first line options available for their management. This review article reviews the etiopathogenesis, natural history, common classification systems and various available treatment options

<SUP>1</SUP>H NMR studies on strongly antiferromagnetically coupled dicopper(II) systems

The 1H NMR spectra of three well-characterized &#956; -phenoxo and &#956; -hydroxo spin coupled dicopper(II) complexes 1, 2, and 3 which are strongly antiferromagnetically coupled in the solid state have been studied in solution. The complexes studied were [(Cu2(DAP)2IPA)(OH)(H2O)](ClO4)2&#183;H2O (1) (DAP = 1,3-diaminopropane; IPA = 2-hydroxy-5-methylisophthalaldehyde), [(Cu2(DMDAP)2IPA)(OH)(H2O)](ClO4)2 (2) (DMDAP = N,N-dimethyl-1,3-diaminopropane), and [(Cu2(AEP)2IPA)(OH)(H2O)](ClO4)2 (3) (AEP = 2-(2-aminoethyl)pyridine). All three complexes exhibit relatively sharp hyperfine shifted NMR signals. Signal assignments were based on intensity and T1 values. An analysis of the relaxation data shows that, for these binuclear copper(II) systems, the reorientational correlation time (&#964;c) is dominated probably by a combination of electronic relaxation &#964;s and rotational correlation time (&#964;r) due to an exchange-modulated dipolar mechanism. The temperature dependence of the isotropic shifts has been interpreted in terms of the contact hyperfine interaction constant (A) and exchange coupling constant (-2J). The fitting of these shifts represents a good method for the evaluation of -2J in solution, which is compared to the solid state -2J value obtained by the SQUID method. The results indicate that the structures and magnetic properties of all three complexes (1-3) support a general correlation with the antiferromagnetic coupling constants as evidenced by both solid and solution studies. Our results show that 1H NMR spectroscopy is an excellent tool to probe the solution structures of magnetically coupled binuclear Cu(II) centers in model complexes as well as biological systems. One of these complexes was crystallized from aqueous solution. The crystal and molecular structure of [(Cu2(DMDAP)2IPA)(OH)(H2O)](ClO4)2 (2) has been determined. This crystallizes in the monoclinic system, space group Cc with formula weight = 692.48, a = 12.472(2) &#197;, b = 19.554(2) &#197;, c = 12.185(12) &#197;, &#946; = 107.48 (9)&#176;, Z = 4. The two Cu atoms in this copper(II) complex are bridged by the oxygen atoms of the phenolate and hydroxy groups. The axial position at one Cu atom is occupied by a water molecule, while another Cu has weak interaction with a perchlorate group. The coordination geometries around the two Cu atoms are distorted square pyramidal and square planar