Measuring the size of a Schroedinger cat state

We propose a measure for the "size" of a Schroedinger cat state, i.e. a quantum superposition of two many-body states with (supposedly) macroscopically distinct properties, by counting how many single-particle operations are needed to map one state onto the other. This definition gives sensible results for simple, analytically tractable cases and is consistent with a previous definition restricted to Greenberger-Horne-Zeilinger-like states. We apply our measure to the experimentally relevant, nontrivial example of a superconducting three-junction flux qubit put into a superposition of left- and right-circulating supercurrent states and find this Schroedinger cat to be surprisingly small.Comment: 5 pages, 3 figure

Trial Production and Testing of Cement-Bonded Particleboard from Rattan Furniture Waste

An investigation was conducted on the use of rattan (cane) furniture waste as furnish material for the manufacture of cement-bonded particleboard (CBP). Laboratory scale CBPs were fabricated from hot water pretreated chopped strands of mixed rattan waste obtained from rattan furniture workers in Ibadan, Oyo State, Nigeria. Three-layered boards of 6-mm thickness were made comprising coarse core and fine surfaces at two density levels of 1,050 kg/m3 and 1,200 kg/m3 three CaCl2 concentration levels of: 2.5%, 3.0%, and 3.5%, and using Portland cement-cane mixing ratios of 2.5:1.0, 2.75:1.0, 3.0:1.0, and 3.25:1.0. After board manufacture, ASTM D 1037 (1998) test procedures were employed to obtain strength and moisture absorption properties. Average properties for bending modulus of rupture (MOR) and modulus of elasticity (MOE) of the boards ranged between 0.5 and 1.6 N/mm2, and 480 and 3,563 N/mm2, respectively. Mean thickness swelling (TS) and water absorption (WA) values ranged between 1.1 and 8.6%, and 31 and 51%, respectively. Analysis of variance showed that except for MOE, the levels at which the density, CaCl2 concentration, and cement-cane mixing ratio were used and their interaction had no significant effects on properties of the board. The relatively low strength and water resistance properties of the boards make them suitable only for use in low-stressed interior applications. Further investigations are, however, required on the effects of different cane preparation procedures and other fabrication variables on board properties. This is necessary to provide the guidelines required to adequately control the fabrication process and optimize material properties

Predistortion performance considering Peak to Average Power ratio reduction in OFDM context

International audienceSome recent communication systems like DVB-T2 standard set up a PAPR reduction technique followed by a linearization's one. So in such a scenario, the performance of the linearization is influenced undoubtedly by the PAPR reduction method. In this paper, we revisit the EVM metric and evaluate a closed form regarding the performance of both the PAPR reduction technique and the linearization's one. We choose the predistortion as a linearization technique and define a predistortion error. Assuming that the baseband OFDM signal is characterized as a complex Gaussian process, we consider the three top categories of PAPR reduction methods presented in [2] and we first study the distribution of the resulted signal. Then, we derive some theoretical expressions of the first and second order moments of the predistortion error and show that the error depends mainly on the PAPR of the signal after PAPR reduction method and on the predistortion quality. Some simulations compared to our proposed model confirm our results

Theoretical analysis of the trade-off between efficiency and linearity of the High Power Amplifier in OFDM context

International audiencePower efficiency and linearity are key parameters of amplification systems but they cannot be achieved simultaneously. A perfect linearity is observed when the power efficiency is low and vice versa. In this paper, we first analyze through some theoretical expressions, the power efficiency and the linearity measured by the Error Vector Magnitude (EVM) metric. Then we propose an analytical trade-off that ensures a good linearity with reasonable efficiency by combining Peak-to-Average Power Ratio (PAPR) reduction and linearization. This analysis is carried out based on Solid State Power Amplifiers (SSPA) and Predistortion (PD) as linearization technique. We show that a trade-off can be achieved for a high distortionless PAPR reduction gain followed by an effective predistortion. Last but not least the most important is to avoid the amplifier saturation by setting the PAPR of the signal after PAPR reduction technique identical to the input back-off (IBO)

On the Thermal History of Calculable Gauge Mediation

Many messenger models with realistic gaugino masses are based on meta-stable vacua. In this work we study the thermal history of some of these models. Analyzing R-symmetric models, we point out that while some of the known messenger models clearly prefer the supersymmetric vacuum, there is a vast class of models where the answer depends on the initial conditions. Along with the vacuum at the origin, the high temperature thermal potential also possesses a local minimum far away from the origin. This vacuum has no analog at zero temperature. The first order phase transition from this vacuum into the supersymmetric vacuum is parametrically suppressed, and the theory, starting from that vacuum, is likely to evolve to the desired gauge-mediation vacuum. We also comment on the thermal evolution of models without R-symmetry.Comment: 22 pages. V2: Comments on the SM effects added. Minor corrections. Reference added. Valuable discussion with S. Abel, J. Jaeckel and V. Khoze acknowledged. V3: Types of EOGM explicitly defined in the introduction. Discussions about the phase transitions expanded. Typo corrected. Journal versio

Business Teacher Education (BTE); A Panacea for Human Capital Development in Nigeria

The focus of this paper is on business teacher education, a panacea for human capital development in Nigeria. Human capital suggests that education, and training, health and standard of living raises the productivity of workers and increases their lifetime earning capacity. Therefore, BTE is a panacea for human capital development because the programme is tailored towards providing skills, knowledge, competencies and attitudes in the students that will enable them to function effectively and efficiently in the world of work, self-reliant and/or employer of labour. Besides, business teacher education has the capacity to develop programmes that respond to current societal issues such as education for improving, basic computational skills, for meeting the needs of the bilingual and bicultural population, for eliminating occupational stereotyping, for assisting people with special needs and for helping the ordinary consumers to function effectively in the private enterprise system. It is recommended that business education in the secondary schools should contribute to the general education of all individuals by providing basic business education and to vocational education of individuals preparing for business career by providing practical training in office and marketing occupations. Keywords: Business Education, Business Educators, Business Community, Human Capital and Skill Development

Optimized Multi-Frequency Spectra for Applications in Radiative Feedback and Cosmological Reionization

The recent implementation of radiative transfer algorithms in numerous hydrodynamics codes has led to a dramatic improvement in studies of feedback in various astrophysical environments. However, because of methodological limitations and computational expense, the spectra of radiation sources are generally sampled at only a few evenly-spaced discrete emission frequencies. Using one-dimensional radiative transfer calculations, we investigate the discrepancies in gas properties surrounding model stars and accreting black holes that arise solely due to spectral discretization. We find that even in the idealized case of a static and uniform density field, commonly used discretization schemes induce errors in the neutral fraction and temperature by factors of two to three on average, and by over an order of magnitude in certain column density regimes. The consequences are most severe for radiative feedback operating on large scales, dense clumps of gas, and media consisting of multiple chemical species. We have developed a method for optimally constructing discrete spectra, and show that for two test cases of interest, carefully chosen four-bin spectra can eliminate errors associated with frequency resolution to high precision. Applying these findings to a fully three-dimensional radiation-hydrodynamic simulation of the early universe, we find that the HII region around a primordial star is substantially altered in both size and morphology, corroborating the one-dimensional prediction that discrete spectral energy distributions can lead to sizable inaccuracies in the physical properties of a medium, and as a result, the subsequent evolution and observable signatures of objects embedded within it.Comment: 15 pages, 13 figures, 2 tables, accepted for publication in the Astrophysical Journa

Meta-stable SUSY Breaking Model in Supergravity

We analyze a supersymmetry (SUSY) breaking model proposed by Intriligator, Seiberg and Shih in a supergravity (SUGRA) framework. This is a simple and natural setup which demands neither extra superpotential interactions nor an additional gauge symmetry. In the SUGRA setup, the U(1)R symmetry is explicitly broken by the constant term in the superpotential, and pseudo-moduli field naturally takes non-zero vacuum expectation value through a vanishing cosmological constant condition. Sfermions tend to be heavier than gauginos, and the strong-coupling scale is determined once a ratio of sfermion to gaugino masses is fixed.Comment: 13 page

Evaluation of Canaanland Camp House B, Ota, Ogun State

Post Occupancy Evaluation (POE) has been identified as one of the key methodologies in identifying the performance of buildings. It is important for building industry professionals as well as end users to understand the efficiency and effectiveness of their buildings through proper analysis of feedback. The purpose of POE is to improve how buildings are constructed by reducing design and maintenance costs, enhancing occupant satisfaction, comfort, and performance, and to increase return on building owners’ investments. This paper adopts a strategic review using POE in an investigative format with particular focus the Camp House B which served as accommodation for post-graduate students of Covenant University and lodging for groups on spiritual programmes. A survey was carried out using a structured questionnaire as research instrument. The 48 Masters students of architecture representing 30.57% of the total of 157 Post Graduate students were chosen as the sample. The study variables were analyzed using descriptive statistics, tests for correlations and significant relationships were established. The results show significant correlation between the time spent in the rooms and the perceived air quality of the building and significant relationship between adequacy of room space and change in needs of the occupant. The paper concludes with results that show relative user comfort in the buildings and rated the buildings condition as good with a rating of 2.88/4.00. The paper recommends concerted efforts towards improving plumbing services and the inclusion of passive cooling features in design solutions. Keywords: Evaluation, Feedback, Maintenance and Performanc