IPTV service based on a content-zapping paradigm

Internet protocol television (IPTV) generically designates a real-time distribution service for multimedia contents over an IP network, such as the Internet. There are many advantages of IPTV deployment over current digital or air broadcast TV signals: integration, the use of the switched internet protocol (IP), the possibility to build home networks that can be used to share multimedia contents over different devices, the easy implementation of video on demand services and the usage of better compression and encryption standards. In order to implement this kind of service, it is extremely useful to have a system that can efficiently classify multimedia contents and users and distribute them in a customized way. This paper proposes a novel IPTV service for the distribution of personalized multimedia contents over IP networks based on the concept of content-zapping, in contrast to traditional channel-zapping: each client system receives a multimedia streaming that is automatically composed by the system based on the user preferences and the user will only interact with the system by requesting a content change or marking a content as favorite. The paper will describe the general functionality of the service and will present the detailed architecture of the IPTV server, the key component of the service infrastructure. The server must maintain a list of media contents residing in other systems and must keep a dynamic classification of the multimedia contents that are stored in its database. This classification is built and gradually refined based on the interactions between clients and multimedia contents. Special attention is given in the paper to the classification model, describing the general ideas that are used to automatically suggest multimedia contents to a specific user (that is characterized by his complete profile). A specific content may be suggested to the user based on the knowledge of the user profile and/or based on specific and dynamic information, such as the user position, the local temperature, date and time. The availability of this information obviously depends on the specific user device that is being used. The proposed system allows any client device to connect, allowing a high level of interoperability. It is also possible to use all the device capabilities and sensors, like Global Positioning System (GPS), accelerometers, light sensors, noise sensors, etc., thus creating a context environment that helps classify each user profile. These context-awareness mechanisms applied to mobile devices with wireless network (802.11b/g/n, WiMAX, GSM, UMTS, etc.) capabilities allow a better user experience and more accurate multimedia suggestions, due to the deep knowledge about the user device, network and environment. The system also allows the users to suggest contents to other users in the same “group of friends”. Several performance tests were already conducted and the results obtained show that the proposed system is very stable and fast, even for high increases on the number of users.     

Study of the impact of wildfire emissions,through MOPITT total CO column,at different spatial scales

The estimation of total carbon monoxide (CO) column has been identified as essential to improve our understanding of its role in the global climate system. The Earth Observing System (EOS) Science Steering Committee and the World Meteorological Organization (WMO) has suggested that a satellite-borne CO sensor, which would operate for extended periods, would be useful for that task. Measurements of Pollution in the Troposphere (MOPITT), on board the Terra spacecraft, is a correlation radiometer for estimating CO vertical profiles and total CO column in the lower atmosphere, through the thermal radiance received in the 4.7 μm spectral region. One of the main sources of CO in the atmosphere is the fires and global biomass-burning emissions that are produced when combustion is not complete, especially in the smouldering phase. This article presents a methodology based on a Fourier technique and spatial analysis in order to estimate the total CO column contribution of wildfires at three different spatial scales. First, in a seasonal study, a Mediterranean country (Spain) is selected, and the main regions affected by fire during four years in the summer season are analysed. Second, in order to estimate CO emissions at a local scale, a large fire (in Spain) and a cluster of fires (in North China) are selected. Third, for a global study at large scale and for comparing with CO and carbon dioxide (CO₂) data from Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), locations in North China, equatorial Africa, and Amazonia are selected. Results obtained show that MOPITT data are suitable to assess and to discriminate CO emissions at local spatial scales. Finally, a qualitative agreement between CO behaviour obtained by MOPITT and CO and CO₂ obtained by SCIAMACHY is found.     

Differential evolution for optimizing the positioning of prototypes in nearest neighbor classification

Nearest neighbor classification is one of the most used and well known methods in data mining. Its simplest version has several drawbacks, such as low efficiency, high storage requirements and sensitivity to noise. Data reduction techniques have been used to alleviate these shortcomings. Among them, prototype selection and generation techniques have been shown to be very effective. Positioning adjustment of prototypes is a successful trend within the prototype generation methodology.Evolutionary algorithms are adaptive methods based on natural evolution that may be used for searching and optimization. Positioning adjustment of prototypes can be viewed as an optimization problem, thus it can be solved using evolutionary algorithms. This paper proposes a differential evolution based approach for optimizing the positioning of prototypes. Specifically, we provide a complete study of the performance of four recent advances in differential evolution. Furthermore, we show the good synergy obtained by the combination of a prototype selection stage with an optimization of the positioning of prototypes previous to nearest neighbor classification. The results are contrasted with non-parametrical statistical tests and show that our proposals outperform previously proposed methods.     

EWR~无头轧制和工字轮式卷取机组

在加热炉之后对钢坯进行焊接 ( EWR○R)的无头轧制工艺和棒卷生产用的工字轮式卷取机组 ,能够消除钢坯间隔时间、降低废品率、减少轧机停机时间、消除冷床上的短棒材、减少切头切尾、消耗件的寿命长、易于车间管理和“定制”盘卷质量。工字轮式卷取机组能够以无扭方法将热轧圆钢、方钢和扁钢卷成高度紧凑的 /大质量卷材 ,以及在不进行中间离线操作的情况下 ,直接提供给下游冷加工生产线     

Estimating willingness to pay for desalinated seawater: the case of Djerba Island,Tunisia

Water scarcity can be a growth-limiting factor. Non-conventional water resources, such as desalinated water, represent an alternative means of guaranteeing access to water while reducing water stress. In this study, a contingent valuation survey carried out in Djerba Island, Tunisia, allows the joint modelling of two decisions: societal support for the construction of a desalination plant and households’ willingness to pay for desalinated water. To the best of the authors’ knowledge, no study to date has addressed this relationship. We find that although a clear majority of households are in favour of using desalinated water, far fewer are willing to pay for it. The article concludes that it is worth studying willingness to pay for desalinated water in developing countries in order to avoid investing in projects where it is doubtful that costs will be recouped.     

Hybrid proton-conducting membranes for polymer electrolyte fuel cells: Phosphomolybdic acid doped poly(2,5-benzimidazole)—(ABPBI-H3PMo12O40)

The synthesis and characterization of a novel hybrid organic-inorganic material formed by phosphomolybdic acid H₃PMo₁₂O₄₀ (PMo₁₂) and poly(2,5-benzimidazole) (ABPBI) is reported. This material, composed of two proton-conducting components, can be cast in the form of membranes from methanesulfonic acid (MSA) solutions. Upon impregnation with phosphoric acid, the hybrid membranes present higher conductivity than the best ABPBI polymer membranes impregnated in the same conditions. These electrolyte membranes are stable up to 200 °C, and have a proton conductivity of 3 × 10⁻² S cm⁻¹ at 185 °C without humidification. These properties make them very good candidates as membranes for polymer electrolyte membrane fuel cells (PEMFC) at temperatures of 100-200 °C.     

Impact of peripheral fragmentation on the steam gasification of an isolated wood charcoal particle in a diffusion-controlled regime

This study focuses on the effect of peripheral fragmentation during gasification of an isolated wood charcoal particle in the regime of diffusional limitations. In fact, all the models available in the literature fail to reproduce the specific changes in biomass charcoals for which conversion increases quasi linearly versus time, whatever the particle size. We assumed this discrepancy is partly due to the fragmentation phenomenon, i.e. the detachment of fragments from the surface of the particle, which is not usually taken into account in models. The classical assumption in percolation models is a critical value of porosity beyond which fragmentation occurs. We compared our model results with experimental data. We demonstrated that in the diffusion-limited regime, the direct extrapolation of such a method to a continuum model is not satisfying. A new criterion of fragmentation based on a critical porosity and a critical porosity gradient is proposed which considerably improves modelling of gasification charcoal particles.     

Synthesis and Characterization of Hydroxyapatite–Wollastonite Composite Powders by Sol–Gel Processing

Composites of hydroxyapatite–wollastonite were synthesized by a sol–gel route using calcium acetate and triethyl phosphate as precursors of hydroxyapatite and high-purity natural wollastonite added in ratios of 20, 50, and 80 wt%. These composites were characterized by thermal analysis, X-ray diffraction, FT-IR and Raman spectroscopy, and scanning and transmission electron microscopic techniques. Formation of hydroxyapatite occurs at a relatively low temperature, about 420°C, accompanied by calcium carbonate; wollastonite remains unreacted. The composites were purified by heat treatment to a higher temperature and washed with hydrochloric acid and distilled water, to produce B-type carbonated hydroxyapatite–wollastonite composites as final products.     

Physicochemical,nutritional and functional characteristics of two underutilised fruit cactus species (Myrtillocactus) produced in central Mexico

The physicochemical, nutritional, and functional variations of Myrtillocactus geometrizans and Myrtillocactus schenckii, were assessed. Variations of characteristics among species and geographic origin were lower compared to prickly pear. Titratable acidity, and total soluble solids varied by 7.7%, and 11%, respectively. Variations of protein (18.5%) and fibre (5.2%) contents were lower when compared to prickly pear. Iron and copper contents make Myrtillocactus a good source of minerals contributing 16% and 20% of daily requirements. Myrtillocactus also could be an outstanding source of fibre (up to 36.9%). Gallic and caffeic acids, and vanillin were identified by HPLC. Betalains, soluble phenolics, and vitamin C contribute to the high antioxidant activity (TEAC) which, if compared with commonly consumed fruits, was higher. The potential for the production of high-quality industrialised products derived from Myrtillocactus is feasible, as long as compositional variations from batch to batch are kept in check.     

The accounting system as an algebraic automaton

This article aims to present a mathematical model to describe the accounting system. In effect, in the literature on accounting we can find several mathematical models trying to introduce the accounting mechanics but in this article we use the concept of algebraic automaton, which has been successfully used in other economic fields, like finance. Thus, from this new point of view we can construct all definitions and accounting techniques as a particular case of the concept of automaton. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 827–842, 2005.