165 research outputs found

    Personalisation of internet based business office layout

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    In current era, the nature of business is ever-changing where communication and interaction between office workers are encouraged as the scope of work for office is expanding. Traditional offices with identical cubicles separated with panels are ineffective because not all workers are in the same activity mode at the same time. Providing and maintaining a comfortable and healthy office environment is vital consideration in designing an office. The interior layout design parameter involved are the comfortability of furniture, surrounding temperature, amount of lighting provided, the quality of indoor air, spatial arrangement, the condition of environment in terms of noise and privacy, and finally the 2D horizontal and vertical layout. This research seeks to identify the factors of interior layout design parameter that will affect the productivity and performance of the workers. The research is conducted using quantitative method. Questionnaire is distributed to the building occupants to evaluate and obtain their opinion on the satisfaction level of the layout at their workplace. The user satisfaction and perception on the existing interior layout design are gathered by using a questionnaire survey. The study proves that the workers are most satisfied with the lighting and least satisfied with the furniture at their existing interior layout design. The workers from both case studies agreed that the interior layout design parameter that has the most effect on the productivity is the environment noise and privacy; while 2D horizontal and vertical layout has the least effect

    Significant characteristics of scheduled and condition-based maintenance in office buildings

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    Sustainability of buildings is one of the main aims in the construction industry. In achieving sustainability, maintenance of buildings and its facilities, which include planning, implementation, and outcome of maintenance activities, becomes an important criterion. This paper aims to identify the significant characteristics of scheduled and condition-based maintenance in office buildings through reviews of relevant literature and a questionnaire survey. The significance of the characteristics was identified through ranking analysis. A semistructured interview was conducted to obtain further details on the characteristics and measures to enhance efficiency of the characteristics. The findings reveal that the dominant characteristics for scheduled maintenance include quality of spare part and material, the level of labor skill and knowledge, and budget allocation for maintenance labor, whereas for condition-based maintenance, the dominant characteristics are the level of manager skill and knowledge, reliability of maintenance data, and financial allocation for the maintenance manager. The study concludes that these dominant characteristics should be considered in the implementation of maintenance strategies

    Predictive Maintenance: Monitoring Tools and Equipment

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    Due to low service quality of maintenance management, high maintenance cost becomes a common issue in building industry of Malaysia. Lack of preventive measure is the problem that resulting poor maintenance performance. So, condition-based maintenance is introduced to improve the maintenance performance. Monitoring tools and equipment is seen as an important factor to ensure the efficiency of condition-based maintenance. So, this paper aims to determine the aspects of monitoring tools and equipment to be concerned in building maintenance, as well as to establish the relationship between the aspects and maintenance cost performance. A quantitative approach is adopted and performed through questionnaire survey. Furthermore, descriptive analysis and correlation analysis are used to analyse the research data. The literature review determines three aspects of monitoring tools and equipment to be considered in maintenance management. Furthermore, the research result demonstrates that the budget allocation for acquisition of monitoring tools and equipment, capability to operate the tools and equipment, as well as availability of the tools and equipment are significantly correlated to the maintenance cost variance. The research recommends the maintenance management to convince the clients or organisation to acquire advanced monitoring tools and equipment for implementation of condition-based maintenance. Besides that, provision of training is encouraged to ensure that the maintenance personnel are able to utilise the tools and equipment

    Vortex in a d-wave superconductor at low temperatures

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    A systematic perturbation theory is developed to describe the magnetic field-induced subdominant ss- and dxyd_{xy}-wave order parameters in the mixed state of a dx2y2d_{x^2-y^2}-wave superconductor, enabling us to obtain, within weak-coupling BCS theory, analytic results for the free energy of a d-wave superconductor in an applied magnetic field H_{c1}\ltsim H\ll H_{c2} from TcT_c down to very low temperatures. Known results for a single isolated vortex in the Ginzburg-Landau regime are recovered, and the behavior at low temperatures for the subdominant component is shown to be qualitatively different. In the case of subdominant dxyd_{xy} pair component, superfluid velocity gradients and an orbital Zeeman effect are shown to compete in determining the vortex state, but for realistic field strengths the latter appears to be irrelevant. On this basis, we argue that recent predictions of a low-temperature phase transition in connection with recent thermal conductivity measurements are unlikely to be correct.Comment: 20 RevTEX pages, 6 EPS figures; considerably expanded versio

    Quantum cohomology via vicious and osculating walkers

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    We relate the counting of rational curves intersecting Schubert varieties of the Grassmannian to the counting of certain non-intersecting lattice paths on the cylinder, so-called vicious and osculating walkers. These lattice paths form exactly solvable statistical mechanics models and are obtained from solutions to the Yang–Baxter equation. The eigenvectors of the transfer matrices of these models yield the idempotents of the Verlinde algebra of the gauged u^(n)k -WZNW model. The latter is known to be closely related to the small quantum cohomology ring of the Grassmannian. We establish further that the partition functions of the vicious and osculating walker model are given in terms of Postnikov’s toric Schur functions and can be interpreted as generating functions for Gromov–Witten invariants. We reveal an underlying quantum group structure in terms of Yang–Baxter algebras and use it to give a generating formula for toric Schur functions in terms of divided difference operators which appear in known representations of the nil-Hecke algebra

    Improving Sparse Representation-Based Classification Using Local Principal Component Analysis

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    Sparse representation-based classification (SRC), proposed by Wright et al., seeks the sparsest decomposition of a test sample over the dictionary of training samples, with classification to the most-contributing class. Because it assumes test samples can be written as linear combinations of their same-class training samples, the success of SRC depends on the size and representativeness of the training set. Our proposed classification algorithm enlarges the training set by using local principal component analysis to approximate the basis vectors of the tangent hyperplane of the class manifold at each training sample. The dictionary in SRC is replaced by a local dictionary that adapts to the test sample and includes training samples and their corresponding tangent basis vectors. We use a synthetic data set and three face databases to demonstrate that this method can achieve higher classification accuracy than SRC in cases of sparse sampling, nonlinear class manifolds, and stringent dimension reduction.Comment: Published in "Computational Intelligence for Pattern Recognition," editors Shyi-Ming Chen and Witold Pedrycz. The original publication is available at http://www.springerlink.co

    Theory of bound polarons in oxide compounds

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    We present a multilateral theoretical study of bound polarons in oxide compounds MgO and \alpha-Al_2O_3 (corundum). A continuum theory at arbitrary electron-phonon coupling is used for calculation of the energies of thermal dissociation, photoionization (optically induced release of an electron (hole) from the ground self-consistent state), as well as optical absorption to the non-relaxed excited states. Unlike the case of free strong-coupling polarons, where the ratio \kappa of the photoionization energy to the thermal dissociation energy was shown to be always equal to 3, here this ratio depends on the Froehlich coupling constant \alpha and the screened Coulomb interaction strength \beta. Reasonable variation of these two parameters has demonstrated that the magnitude of \kappa remains usually in the narrow interval from 1 to 2.5. This is in agreement with atomistic calculations and experimental data for hole O^- polarons bound to the cation vacancy in MgO. The thermal dissociation energy for the ground self-consistent state and the energy of the optically induced charge transfer process (hops of a hole between O^{2-} ions) have been calculated using the quantum-chemical method INDO. Results obtained within the two approaches for hole O^- polarons bound by the cation vacancies (V^-) in MgO and by the Mg^{2+} impurity (V_{Mg}) in corundum are compared to experimental data and to each other. We discuss a surprising closeness of the results obtained on the basis of independent models and their agreement with experiment.Comment: 13 pages, 2 figures, 2 tables, E-mail addresses: [email protected], [email protected]

    Greenberger-Horne-Zeilinger nonlocality for continuous variable systems

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    As a development of our previous work, this paper is concerned with the Greenberger-Horne-Zeilinger (GHZ) nonlocality for continuous variable cases. The discussion is based on the introduction of a pseudospin operator, which has the same algebra as the Pauli operator, for each of the NN modes of a light field. Then the Bell-CHSH (Clauser, Horne, Shimony and Holt) inequality is presented for the NN modes, each of which has a continuous degree of freedom. Following Mermin's argument, it is demonstrated that for NN-mode parity-entangled GHZ states (in an infinite-dimensional Hilbert space) of the light field, the contradictions between quantum mechanics and local realism grow exponentially with NN, similarly to the usual NN-spin cases.Comment: RevTEX; comments are welcomed; new version with minor change

    B -> J/psi K^* Decays in QCD Factorization

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    The hadronic decay B -> J K^* is analyzed within the framework of QCD factorization. The spin amplitudes A_0, A_\parallel and A_\perp in the transversity basis and their relative phases are studied using various different form-factor models for B-K^* transition. The effective parameters a_2^h for helicity h=0,+,- states receive different nonfactorizable contributions and hence they are helicity dependent, contrary to naive factorization where a_2^h are universal and polarization independent. QCD factorization breaks down even at the twist-2 level for transverse hard spectator interactions. Although a nontrivial strong phase for the A_\parallel amplitude can be achieved by adjusting the phase of an infrared divergent contribution, the present QCD factorization calculation cannot say anything definite about the phase phi_\parallel. Unlike B -> J/psi K decays, the longitudinal parameter a_2^0 for B -> J/psi K^* does not receive twist-3 corrections and is not large enough to account for the observed branching ratio and the fraction of longitudinal polarization. Possible enhancement mechanisms for a_2^0 are discussed.Comment: 21 pages, 1 figure, a table and a reference added, some typos correcte

    Microbial inoculation to improve plant performance in mine-waste substrates: A test using pigeon pea (Cajanus cajan)

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    Mining activities alter soil physicochemical and biological properties that are critical for plant establishment. Revitalisation of soil biological properties via microbial inoculations can potentially be adopted to improve vegetation restoration. Here, we evaluate the feasibility of using beneficial microorganisms in the form of commercially available inoculants to enhance plant performance in a non-toxic and infertile mine-waste substrate, using pigeon pea [Cajanus cajan (L) Millsp.] as a test plant. Six treatments were established to investigate the effects of inoculants (Bradyrhizobium spp., microbial mix and uninoculated controls) and water availability (low and moderate) in a factorial design over 6 months. Plant performance was determined by physiological parameters (leaf gas exchange, leaf carbon, nitrogen and stable isotopes) and growth (height and biomass). Plant xylem sap phytohormones were measured to determine the plants' physiological status and effects of inoculation treatments. Results revealed that water had a greater effect on plant growth than inoculation treatments. Inoculation treatments, however, improved some physiological parameters. This study suggests that physical conditions such as soil moisture and nutrient availability may occlude more subtle (direct or interactive) effects of beneficial soil microbes on plant growth and plant condition. Prior knowledge on the biological and physicochemical properties of the soil to be amended, and on plant species-specific responses, would be needed to customise microbial inoculants for maximum benefits to ecological restoration, to support future adoption of this practice
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