477 research outputs found
How to expand the Hamilton market for mutual benefit
The main business of Mument, is to sell maternal and infant products. It is a one- stop store, where customers can find baby and children’s items from new-born until nearly 12 years old, Mument has a membership system, which means customer can deposit 1. getting 15% off when they reach 300 points.. The aims of the research were to improve sales and selling skills, and to develop better marketing methods. The questions for Mument are how to gain better sales and select effective marketing methods. For this research, I have selected quantitative methods, and use a questionnaire to get the primary research results. 18% of customers find a long wait for their order unacceptable, 30% of customers think Mument sales-people lack professional information, and find having only one sales-person in the store at weekends insufficient. 64% customers know about mother and baby product information through friends, and 58% customers know about Mument from friends. Most member’s babies’ birthdays are in April, May, September and October. I recommend that the owner analyse what kind of products customers require frequently, and order these before they ask, have a longer training time to allow sales-persons to acquire professional information, and have sales promotions at specific times
The Photonic Band theory and the negative refraction experiment of metallic helix metamaterials
We develop a theory to compute and interpret the photonic band structure of a
periodic array of metallic helices for the first time. Interesting features of
band structure include the ingenuous longitudinal and circularly polarized
eigenmodes, the wide polarization gap [Science 325, 1513 (2009)], and the
helical symmetry guarantees the existence of negative group velocity bands at
both sides of the polarization gap and band crossings pinned at the zone
boundary with fixed frequencies. A direct proof of negative refraction via a
chiral route [Science 306, 1353 (2004)] is achieved for the first time by
measuring Gooshanchen shift through a slab of three dimensional bona fide helix
metamaterial
Game Theory Based Correlated Privacy Preserving Analysis in Big Data
Privacy preservation is one of the greatest concerns in big data. As one of extensive applications in big data, privacy preserving data publication (PPDP) has been an important research field. One of the fundamental challenges in PPDP is the trade-off problem between privacy and utility of the single and independent data set. However, recent research has shown that the advanced privacy mechanism, i.e., differential privacy, is vulnerable when multiple data sets are correlated. In this case, the trade-off problem between privacy and utility is evolved into a game problem, in which payoff of each player is dependent on his and his neighbors’ privacy parameters. In this paper, we firstly present the definition of correlated differential privacy to evaluate the real privacy level of a single data set influenced by the other data sets. Then, we construct a game model of multiple players, in which each publishes data set sanitized by differential privacy. Next, we analyze the existence and uniqueness of the pure Nash Equilibrium. We refer to a notion, i.e., the price of anarchy, to evaluate efficiency of the pure Nash Equilibrium. Finally, we show the correctness of our game analysis via simulation experiments
Robust retrieval of material chemical states in X-ray microspectroscopy
X-ray microspectroscopic techniques are essential for studying morphological
and chemical changes in materials, providing high-resolution structural and
spectroscopic information. However, its practical data analysis for reliably
retrieving the chemical states remains a major obstacle to accelerating the
fundamental understanding of materials in many research fields. In this work,
we propose a novel data formulation model for X-ray microspectroscopy and
develop a dedicated unmixing framework to solve this problem, which is robust
to noise and spectral variability. Moreover, this framework is not limited to
the analysis of two-state material chemistry, making it an effective
alternative to conventional and widely-used methods. In addition, an
alternative directional multiplier method with provable convergence is applied
to obtain the solution efficiently. Our framework can accurately identify and
characterize chemical states in complex and heterogeneous samples, even under
challenging conditions such as low signal-to-noise ratios and overlapping
spectral features. Extensive experimental results on simulated and real
datasets demonstrate its effectiveness and reliability.Comment: 12 page
Thermal Chemical Conversion of High-Density Polyethylene for the Production of Valuable Carbon Nanotubes Using Ni/AAO Membrane Catalyst
© 2017 American Chemical Society. Thermal chemical conversion of waste plastics for syngas production is a promising alternative method for the management of waste plastics. However, one of the challenges of facilitating the deployment of this technology is the low economic benefit of waste-plastic recycling. By producing a high-value carbon nanotubes (CNTs) byproduct, an interesting alternative solution is provided. To further enhance the quality of CNTs produced from catalytic thermal chemical conversion of waste plastics, a template-based catalyst (Ni/anodic aluminum oxide, AAO) is proposed in this work. In addition, reaction temperature, Ni content and water injection were studied for their influences on the formation of CNTs on Ni/AAO using a two-stage fixed bed reactor. Various analytical methods, e.g., scanning electronic microscopy (SEM) and X-ray diffraction (XRD), were used to evaluate the performance of catalyst in relation to the production of CNTs. The results show that a higher loading of Ni on AAO resulted in the formation of metal particles with various sizes, thus leading to the production of nonuniform CNTs. In addition, an optimal catalytic temperature of 700 °C is suggested for the production of CNTs. Because the catalyst might not be activated at 600 °C, which produced a low yield of CNTs. However, a reaction temperature of 800 °C resulted in a low yield of CNTs. Carbon deposition decreased with an increase of steam injection, but the quality of CNTs formation in relation to the uniform of CNTs seemed to be improved in the presence of steam
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