Radiation from cylindrical leaky waves

Formulas are derived for the far-infrared radiation pattern of cylindrical leaky waves propagating on a planar surface. The formulas can be used to predict the radiation pattern of a general class of leaky-wave antennas, consisting of a finite-size source which excites a radially propagating leaky wave on some planar surface. Leaky-wave antennas consisting of antenna elements embedded in dielectric layers (microstrip elements) fall into this category. Using the equivalence principle, formulas are derived for both transverse electric (TE) and transverse magnetic (TM) leaky waves with arbitrary propagation constants. The formulas allow for radiation from cylindrical apertures of arbitrary size, so that the effect of truncating the supporting planar surface with an absorbing material can be determined. Particular attention is devoted to the case of a leaky wave for which the real and imaginary parts of the complex propagation constant are equal, since this type of wave has been shown to be responsible for broadside radiation in certain leaky-wave antennas comprised of dielectric layers     

Automatic Image Annotation Based on Generalized Relevance Models

This paper presents a generalized relevance model for automatic image annotation through learning the correlations between images and annotation keywords. Different from previous relevance models that can only propagate keywords from the training images to the test ones, the proposed model can perform extra keyword propagation among the test images. We also give a convergence analysis of the iterative algorithm inspired by the proposed model. Moreover, to estimate the joint probability of observing an image with possible annotation keywords, we define the inter-image relations through proposing a new spatial Markov kernel based on 2D Markov models. The main advantage of our spatial Markov kernel is that the intra-image context can be exploited for automatic image annotation, which is different from the traditional bag-of-words methods. Experiments on two standard image databases demonstrate that the proposed model outperforms the state-of-the-art annotation models.     

Three-dimensional virtual-reality surgical planning and soft-tissueprediction for orthognathic surgery

Complex maxillofacial malformations continue to present challenges in analysis and correction beyond modern technology. The purpose of this paper is to present a virtual reality workbench for surgeons to perform virtual orthognathic surgical planning and soft-tissue prediction in three dimensions. A resulting surgical planning system, i.e., three-dimensional virtual reality surgical planning and soft-tissue prediction for orthognathic surgery, consists of four major stages: computed tomography (CT) data post-processing and reconstruction, three-dimensional (3-D) color facial soft-tissue model generation, virtual surgical planning and simulation, soft-tissue-change preoperative prediction. The surgical planning and simulation are based on a 3D CT reconstructed bone model, whereas the soft-tissue prediction is based on color texture-mapped and individualized facial soft-tissue model. Our approach is able to provide a quantitative osteotomy-simulated bone model and prediction of postoperative appearance with photorealistic quality. The prediction appearance can be visualized from any arbitrary viewing point using a low-cost personal computer-based system. This cost-effective solution can be easily adopted in any hospital for daily use     

Leaky-wave propagation and radiation for a narrow-beammultiple-layer dielectric structure

Previous work has demonstrated that very narrow beam radiation patterns can be obtained from a simple source embedded within multiple dielectric layers of appropriate thicknesses above a ground plane. The configuration consists of dielectric layers having permittivities ϵ₁ and ϵ₂ stacked in an alternating arrangement, with ϵ₂>ϵ₁. This narrow-beam effect can be attributed to weakly attenuated leaky waves that exist on the structure. Simple asymptotic formulas for the propagation and attenuation constants are derived. The formulas show how the beamwidth varies with the number of layers and the material constants. The exact radiation pattern is compared with the leaky-wave pattern for a specific case to demonstrate the role of the leaky waves in determining the total pattern     

Manufacture of Multilayered Artificial Cell Membranes through Sequential Bilayer Deposition on Emulsion Templates

Efforts to manufacture artificial cells that replicate the architectures, processes and behaviours of biological cells are rapidly increasing. Perhaps the most commonly reconstructed cellular structure is the membrane, through the use of unilamellar vesicles as models. However, many cellular membranes, including bacterial double membranes, nuclear envelopes, and organelle membranes, are multilamellar. Due to a lack of technologies available for their controlled construction, multilayered membranes are not part of the repertoire of cell-mimetic motifs used in bottom-up synthetic biology. To address this, we developed emulsion-based technologies that allow cell-sized multilayered vesicles to be produced layer-by-layer, with compositional control over each layer, thus enabling studies that would otherwise remain inaccessible. We discovered that bending rigidities scale with the number of layers and demonstrate inter-bilayer registration between coexisting liquid–liquid domains. These technologies will contribute to the exploitation of multilayered membrane structures, paving the way for incorporating protein complexes that span multiple bilayers.     

丙烯酸酯防钻绒涂层剂的合成研究

介绍了一种乳液聚合方法,通过种子乳液聚合,选用合适的聚合单体,探讨了引发剂和乳化剂的品种及用量对聚合反应的影响,最终确定了反应工艺条件,合成了一种丙烯酸酯防钻绒涂层剂。     

Partner selection model and soft computing approach for dynamic alliance of enterprises

Partner selection is an active research topic in agile manufacturing and supply chain management. In this paper, the problem is described by a 0-1 integer programming with non-analytical objective function. Then, the solution space is reduced by defining the inefficient candidate. By using the fuzzy rule quantification method, a fuzzy logic based decision making approach for the project scheduling is proposed. We then develop a fuzzy decision embedded genetic algorithm. We compare the algorithm with tranditional methods. The results show that the suggested approach can quickly achieve optimal solution for large size problems with high probability. The approach was applied to the partner selection problem of a coal fire power station construction project. The satisfactory results have been achieved.     

EFFECT OF UNCOUPLING OXIDATIVE PHOSPHORYLATION ON THE ECONOMICS OF THE ACTIVATED SLUDGE PROCESS

Conventionally, activated sludge units are aerated continuously for the biological oxidation of organic carbon and ammonium. The respiration of the microflora which develops is tightly coupled to adenosine triphosphate (ATP) formation. (ATP is the energy currency of the cell, growth is proportional to the ATP formed). A management strategy is reported here which uses alternating periods of aeration and non-aeration (AAA process), then respiration is uncoupled from ATP formation and hence from cell growth. Less sludge is formed but the removal of Biochemical Oxygen Demand (BOD) is no less efficient.

In addition, ammonium is oxidized to nitrate during aeration and is then denitrified in the non-aerated period. Savings of 25% to 40% in aeration charges have been demonstrated. This entails no change in the physical design of the plant, no reductant is needed for denitrification, foam is reduced and the sludge settles well. The final effluent demands less chlorine and has a low nitrogen content. The control of the periods of air on/air off can be automated in response to the rate of uptake of dissolved oxygen (DO).     

Mean-Life Indifference Pricing for Quantity Purchases

Traditionally, consumers pay a fixed price for a quantity of items based on a presumed mean life. In many cases (i.e., federal government procurement) a sample of items is pretested to determine mean life and hence conformance to the contract. This paper suggests an alternative scheme based on a price indifference curve h(φ) which specifies the unit cost given mean life φ, which is estimated based on the actual performance of the first r items that fail. The paper develops a specific form for the indifference function and a procedure for estimating both φ and h(φ) and presents an example.