PrivateJobMatch: A Privacy-Oriented Deferred Multi-Match Recommender System for Stable Employment

Coordination failure reduces match quality among employers and candidates in the job market, resulting in a large number of unfilled positions and/or unstable, short-term employment. Centralized job search engines provide a platform that connects directly employers with job-seekers. However, they require users to disclose a significant amount of personal data, i.e., build a user profile, in order to provide meaningful recommendations. In this paper, we present PrivateJobMatch -- a privacy-oriented deferred multi-match recommender system -- which generates stable pairings while requiring users to provide only a partial ranking of their preferences. PrivateJobMatch explores a series of adaptations of the game-theoretic Gale-Shapley deferred-acceptance algorithm which combine the flexibility of decentralized markets with the intelligence of centralized matching. We identify the shortcomings of the original algorithm when applied to a job market and propose novel solutions that rely on machine learning techniques. Experimental results on real and synthetic data confirm the benefits of the proposed algorithms across several quality measures. Over the past year, we have implemented a PrivateJobMatch prototype and deployed it in an active job market economy. Using the gathered real-user preference data, we find that the match-recommendations are superior to a typical decentralized job market---while requiring only a partial ranking of the user preferences.Comment: 45 pages, 28 figures, RecSys 201

Generic absence of strong singularities and geodesic completeness in modified loop quantum cosmologies

Different regularizations of the Hamiltonian constraint in loop quantum cosmology yield modified loop quantum cosmologies, namely mLQC-I and mLQC-II, which lead to qualitatively different Planck scale physics. We perform a comprehensive analysis of resolution of various singularities in these modified loop cosmologies using effective spacetime description and compare with earlier results in standard loop quantum cosmology. We show that the volume remains non-zero and finite in finite time evolution for all considered loop cosmological models. Interestingly, even though expansion scalar and energy density are bounded due to quantum geometry, curvature invariants can still potentially diverge due to pressure singularities at a finite volume. These divergences are shown to be harmless since geodesic evolution does not break down and no strong singularities are present in the effective spacetimes of loop cosmologies. Using a phenomenological matter model, various types of exotic strong and weak singularities, including big rip, sudden, big freeze and type-IV singularities, are studied. We show that as in standard loop quantum cosmology, big rip and big freeze singularities are resolved in mLQC-I and mLQC-II, but quantum geometric effects do not resolve sudden and type-IV singularities.Comment: Minor revision to match published version in CQ

Geodesic completeness and the lack of strong singularities in effective loop quantum Kantowski-Sachs spacetime

Resolution of singularities in the Kantowski-Sachs model due to non-perturbative quantum gravity effects is investigated. Using the effective spacetime description for the improved dynamics version of loop quantum Kantowski-Sachs spacetimes, we show that even though expansion and shear scalars are universally bounded, there can exist events where curvature invariants can diverge. However, such events can occur only for very exotic equations of state when pressure or derivatives of energy density with respect to triads become infinite at a finite energy density. In all other cases curvature invariants are proved to remain finite for any evolution in finite proper time. We find the novel result that all strong singularities are resolved for arbitrary matter. Weak singularities pertaining to above potential curvature divergence events can exist. The effective spacetime is found to be geodesically complete for particle and null geodesics in finite time evolution. Our results add to a growing evidence for generic resolution of strong singularities using effective dynamics in loop quantum cosmology by generalizing earlier results on isotropic and Bianchi-I spacetimes.Comment: Revised version. Discussion in the proof on absence of strong singularities expanded. References added. To appear in CQ

Analyse the wine market at Budget Liquor 2009 Limited to develop customer segmentation profiles

The aim of the research is to analyse the wine market at Budget Liquor 2009 Limited to develop customer segmentation profiles, as the organisation wants to grow its wine market. It is a limited company, which is a SME. It is an off-license retail liquor business which offers alcoholic and non-alcoholic drinks to customers above the legal age of 18 and follows the rules and regulations of the Sale and Supply of Alcohol Act 2012. In this research, a SWOT Analysis of Budget Liquor 2009 Limited is done to identify the business strategies and challenges faced by it, internally and externally. As the alcohol business is a vast growing one, it has extended from liquor stores to pubs and super markets (Direct and Indirect competitors). In this research the literature review is done on various categories, such as small business in New Zealand, importance of a business plan, market segmentation, alcohol and wine industry. This research was conducted using mixed methods (qualitative and quantitative). Qualitative method involved a semi structured face to face interview of 30 to 40 minutes with the store owner and the store manager. Quantitative method involved a customer survey, conducted on a sample of 30 customers by placing the questionnaire in the form of a hard copy. The data obtained from these methods is helpful for the strategies to be followed in increasing the wine market. The findings from the customer survey and interviews about the wine market were helpful in analysing the problems related to product ranges, staff knowledge, and competitors. By analysing the problems there are certain recommendations given to the organisation to improve its wine market. Therefore, these recommendations must be implemented by the organisation immediately to increase its wine market