A Multi-channel Application Framework for Customer Care Service Using Best-First Search Technique

It has become imperative to find a solution to the dissatisfaction in response by mobile service providers when interacting with their customer care centres. Problems faced with Human to Human Interaction (H2H) between customer care centres and their customers include delayed response time, inconsistent solutions to questions or enquires and lack of dedicated access channels for interaction with customer care centres in some cases. This paper presents a framework and development techniques for a multi-channel application providing Human to System (H2S) interaction for customer care centre of a mobile telecommunication provider. The proposed solution is called Interactive Customer Service Agent (ICSA). Based on single-authoring, it will provide three media of interaction with the customer care centre of a mobile telecommunication operator: voice, phone and web browsing. A mathematical search technique called Best-First Search to generate accurate results in a search environmen

One-dimentional magnonic crystal as a medium with magnetically tunable disorder on a periodical lattice

We show that periodic magnetic nanostructures (magnonic crystals) represent an ideal system for studying excitations on disordered periodical lattices because of the possibility of controlled variation of the degree of disorder by varying the applied magnetic field. Ferromagnetic resonance (FMR) data collected inside minor hysteresis loops for a periodic array of Permalloy nanowires of alternating width and magnetic force microscopy images of the array taken after running each of these loops were used to establish convincing evidence that there is a strong correlation between the type of FMR response and the degree of disorder of the magnetic ground state. We found two types of dynamic responses: anti-ferromagnetic (AFM) and ferromagnetic (FM), which represent collective spin wave modes or collective magnonic states. Depending on the history of sample magnetization either AFM or FM state is either the fundamental FMR mode or represents a state of a magnetic defect on the artificial crystal. A fundamental state can be transformed into a defect one and vice versa by controlled magnetization of the sample.Comment: 4 pages, 3 figures, Letter paper, already submitted to PR

Consumer Preference for Rice Consumption in Nigeria

Rice consumption is of interest to the Nigerian economy because of the huge amount of foreign exchange being spent on its importation and the consequent depletion of scarce resources on which the level of economic activities and productivity are based. This study was aimed at identifying the quality of rice preferred by Nigerians for rice food recipes and consequently efforts made to improve the quality of locally produced rice to the taste of Nigerians. A total of 23 rice varieties were acquired from experimental fields of National Cereal Research Institute (NCRI), International Institute of Tropical Agriculture (IITA) in Ibadan and Badegi Rice Breeding Centre in Bida. Consumer preference survey of boiled rice and ‘Tuwo’ foods were carried out in 6 major commercial and traditional cities of Nigeria to determine the quality of rice preferred for boiled rice and ‘Tuwo’ rice foods. The survey was in questionnaire format and was carried out in Bida (Niger State), Zaria (Kaduna State), Maiduguri (Borno State), Benin (Edo State), Port-Harcourt (Rivers state) and Ibadan (Oyo State). Consumers preferred parboiled over unparboiled rice and moderate to flaky rice quality over to soft and sticky rice foods. The rating by taste panelists in Bida, Zaria and Maiduguri metropolis indicated IRAT 112, FARO 15, ITA 117 and ITA 123 were most preferred for ‘Tuwo’ foods, while the least-preferred varieties were ITA 132 and TOX 1768. Consumers also preferred high amylose rice for ‘Tuwo’ to low amylose, sticky rice quality. Also the rating of 6 rice varieties with respect to boiled rice indicated that ITA 117, IART 112 and FARO 15 were most preferred for boiled rice, while TOX 1768 and ITA 132 were the least-preferred in Rivers, Edo, and Oyo States perhaps as a result of people’s preference for flaky rice quality for most of their rice recipes. The results indicated that most Nigerians prefer rice with moderate to high flaky rice quality suggesting that in any rice improvement programme in Nigeria these characteristics should be given a premium. &nbsp

Heavy metal concentrations in some organs of African catfish (Clarias gariepinus) from Eko-Ende Dam, Ikirun, Nigeria

The contents of the heavy metals Fe, Zn, Cu, Mn, Pb, Cd and As were examined in the liver, heart, gills, kidney and muscles of the fish Clarias gariepinus from Eko-Ende dam in Ikirun, the capital of Ifelodun Local Government of Osun State, Nigeria. C. gariepinus is the fish of choice and the most demanded in the southwest of Nigeria. The highest metal concentrations were in the liver and the gills while the lowest was in the muscles. The general deceasing order of metal accumulation in the organs was Fe > Zn > Cu > Mn > Cd. Lead and arsenic were not detected in any organ. The values were of lower concentrations than found in many other dams and rivers in Nigeria and some other countries. The values were also lower than the FAO/WHO recommended maximum limits in fish samples, making the fish to be safe and not of any hazards for the consumers

Coupled magnetic nanostructures: Engineering lattice configurations

We present a systematic investigation of tunable magnetization dynamics of coupled magnetic nanostructures, arranged in one-dimensional arrays of horizontally and vertically coupled linear chains and in two-dimensional arrays of square artificial spin ice lattice. The spatial distribution of the demagnetization field is markedly sensitive to the lattice arrangement, leading to a significant modification of the collective behavior of static and dynamic properties of the arrays. Using ferromagnetic resonance spectroscopy, the engineering of demagnetizing factors with various lattice arrangements has been established quantitatively. The signature of distinct spin wave modes, spatially localized in the constituent nanomagnets, was observed and tuned by the lattice arrangements and applied field orientation. The experimental results are well complemented with micromagnetic simulations

Collective spin waves in arrays of Permalloy nanowires with single-side periodically modulated width

We have experimentally and numerically investigated the dispersion of collective spin waves prop-agating through arrays of longitudinally magnetized nanowires with periodically modulated width. Two nanowire arrays with single-side modulation and different periodicity of modulation were studied and compared to the nanowires with homogeneous width. The spin-wave dispersion, meas-ured up to the third Brillouin zone of the reciprocal space, revealed the presence of two dispersive modes for the width-modulated NWs, whose amplitude of magnonic band depends on the modula-tion periodicity, and a set of nondispersive modes at higher frequency. These findings are different from those observed in homogeneous width NWs where only the lowest mode exhibits sizeable dis-persion. The measured spin-wave dispersion has been satisfactorily reproduced by means of dynam-ical matrix method. Results presented in this work are important in view of the possible realization of frequency tunable magnonic device

Tunable 2-D magnonic crystals: effect of packing density

Magnonic crystals, periodic arrays of magnetic structures, have emerged as a promising platform for manipulating and controlling spin waves in magnetic materials. Magnetic antidot nanostructures, representing 2-D magnonic crystals, are versatile platforms for controlling and manipulating magnons. In this work, we systematically investigate the effects of inter-hole spacing and lattice (rhombic and honeycomb) arrangements on the dynamic properties of Ni80Fe20 antidot structures. The dynamic responses of antidot lattices of fixed hole diameter (d = 280 nm) and inter-hole spacing (s) between 90 and 345 nm are investigated using broadband ferromagnetic spectroscopy. Multiple resonance modes sensitive to s are observed due to the inhomogeneous internal field distribution induced by the presence of holes. There is a marked variation in mode frequency, mode intensity and the number of modes for rhombic antidot lattice as the inter-hole spacing and applied field direction are varied. Our experimental results are in good agreement with micromagnetic simulations. Our findings may find application in the design of magnonic-based devices

Brillouin light scattering studies of planar metallic magnonic crystals

The application of Brillouin light scattering to the study of the spin-wave spectrum of one- and two-dimensional planar magnonic crystals consisting of arrays of interacting stripes, dots and antidots is reviewed. It is shown that the discrete set of allowed frequencies of an isolated nanoelement becomes a finite-width frequency band for an array of identical interacting elements. It is possible to tune the permitted and forbidden frequency bands, modifying the geometrical or the material magnetic parameters, as well as the external magnetic field. From a technological point of view, the accurate fabrication of planar magnonic crystals and a proper understanding of their magnetic excitation spectrum in the GHz range is oriented to the design of filters and waveguides for microwave communication systems

Magnetic Tunability of Permalloy Artificial Spin Ice Structures

This paper reports tunable Ni80Fe20 artificial spin ice structures of various geometrical lattice arrangements as a function of film thickness. We achieve the magnetic tunability by three distinct methods namely, geometrical arrangements of nanomagnetic elements in the form of square, kagome, and triangular lattices with the variation in film thickness (20, 30, and 50 nm) for each geometry and the applied field orientations. Magnetic force microscopy reveals that the nanoelements are in single-domain states, obeying the spin ice rules for the 20-nm-thick spin ice structures. A combination of nanoelements in single-domain and vortex states is observed with the increase in thickness up to 30 nm. For the 50-nm-thick elements, vortex and flux closure states are in evidence. Broadband ferromagnetic resonance spectroscopy establishes the presence of distinct resonant modes that are spatially localized in the nanomagnets of different orientations and, hence, can be controlled by the applied field orientations. The role of shape anisotropy on the static and dynamic properties is investigated systematically and complemented by extensive micromagnetic simulations. The results show great potential towards designing reconfigurable magnonic crystals for microwave filter applications