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排序方式: 共有236条查询结果,搜索用时 31 毫秒
31.
This paper focuses on the implementation of Multi-Criteria Decision Making (MCDM) methods to evaluate the workforce competence in apparel industry. In this study, the Analytic Hierarchy Process (AHP), the Weighted Sum Model (WSM) and the Weighted Product Model (WPM) are suggested to solve workforce selection problem. The use of these methods is expected to help choose the best operator among several alternatives. Based on three criteria, each worker is evaluated in each executed operation. The criteria are a Quality Index ‘QI’, an Activity ‘A’ and an Attendance Rate ‘AR’. Thanks to the MCDM methods, scores allowing an objective classification of operators are obtained. Experimental results on AHP, WSM and WPM methods show the same decisions with the same workers’ classification from the best to the worst alternative. The resulting database contributes to the line balancing optimization by choosing for each operation, and as far as possible, the most competent operator.  相似文献   
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The aim of this work was to stabilize oil-in-water nanoemulsion containing sage (salvia officinalis) essential oil, for enhancing its physicochemical stability and enlarging its industrial applications. New β-cyclodextrin nanosponges were synthesized by polycondensation using naphthalene dicarboxylic acid as cross-linking agent, the latter system was characterized by FTIR spectroscopy, SEM, BET, and powder XRD. Nanoemulsions stabilized by free β-cyclodextrin or nanosponges were prepared, their physicochemical properties were determined (particles size, zeta potential, viscosity, turbidity, and essential oil content) and their stability was studied at different storage temperatures (4?°C, 20?°C, and 40?°C) during 3?months. Pharmaceutical application of prepared nanoemulsions was investigated in vitro by dissolution test study and in vivo by their antidiabetic activity evaluation in rats. Sage essential oil nanoemulsion stabilized by β-cyclodextrin-naphthalene dicarboxylic acid nanosponges presents very high stability and promising uses in pharmaceutical industry.  相似文献   
34.
The energy management of hybrid electric vehicles is becoming an interesting topic for many researchers. Furthermore, the wise choice of the energy management strategy allows not only the best distribution of the power between the used sources, but also it allows reduction of consumption, increase in the lifetime of the sources, and improves the autonomy of the hybrid electric vehicle. The autonomy is guaranteed by the optimization of the embedded sources. In this study, the hybrid system consists of combining the fuel cell as the main source with the battery as the auxiliary source. The novelty of the proposed energy management strategy for the studied hybrid system is the combination between interconnection and damping assignment‐passivity based control and the Hamiltonian Jacobi Bellman method. The stability proof is given and the efficiency of the proposed strategy is proved by the experimental work, where the obtained results show the good and adequate results to the proposed scenario.  相似文献   
35.
Historic masonry buildings under earthquakes – Load‐bearing behaviour in contradiction to the currently applied methods of analysis The stability of historic masonry buildings must be guaranteed not only under normal conditions, but also during natural disasters. The seismic assessment of the masonry buildings of the Gründerzeit (1840–1918) in Vienna is a central topic in the qualitative and constructive assessment. Although masonry construction has been used for many centuries, the realistic evaluation of the load‐bearing behaviour is still a complex challenge. The methods of analysis according to current regulations are only insufficiently able to reflect the real load‐bearing behaviour and the possible activation of global failure mechanisms. As a result, the simplified verification is often difficult to calculate for many historic buildings, and questionable reinforcement measures are taken to compensate, even though the buildings have already experienced several earthquakes and survived most of them without damage. The present work deals with the approaches of current methods of analysis and aims to identify problem points and to compare them with time history analysis, which is supported by a powerful material model based on test series. It is shown that the conventional analysis for the historic masonry buildings without consideration of the interaction and load transfer effects as well as the characteristic construction methods only partially reflect the real load‐bearing behaviour. The work is intended to be a contribution to the technical expert discussions on the seismic safety of historic buildings and to stimulate the discussion on the formulation of realistic methods of analysis.  相似文献   
36.
In this paper, we study the water-wave flow under a floating body of an incident wave in a fluid. This model simulates the phenomenon of waves abording a floating ship in a vast ocean. The same model, also simulates the phenomenon of fluid-structure interaction of a large ice sheet in waves. According to this method. We divide the region of the problem into three subregions. Solutions, satisfying the equation in the fluid mass and a part of the boundary conditions in each subregion, are given. We obtain such solutions as infinite series including unknown coefficients. We consider a limited number only of the coefficients by truncating the infinite series and satisfy the remaining boundary conditions approximately. Numerical experiments show that the results are acceptable. Tables are given along with the graph of the system of the resulting streamlines and the dynamical pressure acting on the obstacle. The drawn system of streamlines shows the correctness of the solution and the pressure is maximum on the side facing the upstream extremity of the channel. The same procedure can be adequately applied for problems with more complicated geometry and other phenomenon can thus be simulated.  相似文献   
37.

The 2,7,12,17-tetra-tert-butyl 5,10,15,20-tetraaza-21,23H-porphine (TTBTP) films were prepared using thermal evaporation technique. The X-ray diffraction (XRD) of the powder showed that TTBTP is polycrystalline with a tetragonal system. Also, the analysis of XRD pattern shows that the TTBTP film of thickness 55 nm has a crystallite size of 24.69 nm which tends to increase with the film thickness. By SEM of 177 nm thick TTBTP film, the topography of the surface is characterized by significant spherical granules. The mean diameter was estimated to be 250 nm for the spherical granules. It was observed that the conductivity increases with increasing the film thickness. Also, the TTBTP is a semiconductor film with thermally activated conduction mechanisms. The current–density–voltage (JV) characteristics showed Ohmic drives in low voltage, whereas the space charge limited conductivity mechanism is familiar in the high voltage region. The carrier mobility values of TTBTP film are relatively the same for other organic molecules. The 50 nm TTBTP film has a carrier mobility of 1.48?×?10??9 cm2 V??1 s??1, which increases with increasing the film thickness.

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38.
Social annotation systems (SAS) allow users to annotate different online resources with keywords (tags). These systems help users in finding, organizing, and retrieving online resources to significantly provide collaborative semantic data to be potentially applied by recommender systems. Previous studies on SAS had been worked on tag recommendation. Recently, SAS‐based resource recommendation has received more attention by scholars. In the most of such systems, with respect to annotated tags, searched resources are recommended to user, and their recent behavior and click‐through is not taken into account. In the current study, to be able to design and implement a more precise recommender system, because of previous users' tagging data and users' current click‐through, it was attempted to work on the both resource (such as web pages, research papers, etc.) and tag recommendation problem. Moreover, by applying heat diffusion algorithm during the recommendation process, more diverse options would present to the user. After extracting data, such as users, tags, resources, and relations between them, the recommender system so called “Swallow” creates a graph‐based pattern from system log files. Eventually, following the active user path and observing heat conduction on the created pattern, user further goals are anticipated and recommended to him. Test results on SAS data set demonstrate that the proposed algorithm has improved the accuracy of former recommendation algorithms.  相似文献   
39.
The thermal behavior of hydrogenated palm kernel oil-in-water emulsions, which differed in their milk-protein composition, was studied in parallel with other characteristic parameters such as the aggregation/coalescence of fat droplets, and the proportion of adsorbed proteins at the oil/water interface. DSC was applied to monitor the crystallization and melting behavior of nonemulsified and emulsified fat samples. Comparison between nonemulsified and emulsified fat samples showed that in emulsified samples the initial temperature of fat crystallization and the temperature of the completion of melting were invariably lower and slightly higher, respectively. Furthermore, in complex food emulsions the supercooling temperature needed to initiate fat crystallization and the variation in its growth rate in the cooling experiment were dependent on the amount and nature of the adsorbed proteins. Our results indicate that the total replacement of milk proteins by whey proteins affected the fat crystallization behavior of emulsified fat droplets, in parallel with changes in their protein surface coverage and in their physical stability against fat droplet agglomeration.  相似文献   
40.
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