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521.
522.
Automatic estimation of crowd density using texture   总被引:2,自引:0,他引:2  
This paper considers the role of automatic estimation of crowd density and its importance for the automatic monitoring of areas where crowds are expected to be present. A new technique is proposed which is able to estimate densities ranging from very low to very high concentration of people, which is a difficult problem because in a crowd only parts of people's body appear. The new technique is based on the differences of texture patterns of the images of crowds. Images of low density crowds tend to present coarse textures, while images of dense crowds tend to present fine textures. The image pixels are classified in different texture classes and statistics of such classes are used to estimate the number of people. The texture classification and the estimation of people density are carried out by means of self organising neural networks. Results obtained respectively to the estimation of the number of people in a specific area of Liverpool Street Railway Station in London (UK) are presented.  相似文献   
523.
This paper outlines briefly the history of radiation protection, touches on some of the early incidents of overexposure, describes monitoring (detection and measurement) methods and the development of standards for health protection, and compares the monitoring of radioactive materials to that of nonradioactive toxic chemicals. The authors suggest that the lessons learned from the radiation experience will be helpful in dealing with the current problems of hazardous chemicals. *** DIRECT SUPPORT *** AZ802019 00005  相似文献   
524.
Crystalline NiS and CoS particles have considerably greater toxic and cell transforming activity than amorphous NiS and CoS particles. These differences in biological activities were attributable to the active phagocytosis of crystalline metal sulfides particles compared with low uptake of amorphous particles. An examination of the surface of crystalline and amorphous metal sulfide particles revealed that cry-stalline NiS and CoS have a net negative surface charge while the surface charge of the amorphous derivatives appears to be positive. Additionally, chemical reduction of NiS particles with LiAlH4 enhanced their entry into cells. X-ray photoelectron spectroscopy analysis of amorphous and crystalline NiS showed that the outermost surface of the two compounds (1–4 nanometers) differed with respect to the Ni/S ratio and the sulfur oxidation state.  相似文献   
525.
This paper presents an attempt to model the water balance in the metropolitan center landfill (MCL) in Salvador, Brazil. Aspects such as the municipal solid waste (MSW) initial water content, mass loss due to decomposition, MSW liquid expelling due to compression and those related to weather conditions, such as the amount of rainfall and evaporation are considered. Superficial flow and infiltration were modeled considering the waste and the hydraulic characteristics (permeability and soil-water retention curves) of the cover layer and simplified uni-dimensional empirical models. In order to validate the modeling procedure, data from one cell at the landfill were used. Monthly waste entry, volume of collected leachate and leachate level inside the cell were monitored. Water balance equations and the compressibility of the MSW were used to calculate the amount of leachate stored in the cell and the corresponding leachate level. Measured and calculated values of the leachate level inside the cell were similar and the model was able to capture the main trends of the water balance behavior during the cell operational period.  相似文献   
526.
The coastal zone of the Brazilian state of Maranhão is an area characterized by a large variety of human activities and services, in particular in the Itaqui-Bacanga port complex (IBC). The IBC is an area prone to oil spills resulting from the processes of transportation, storage, and tank cleaning. The present study aimed to map the different physical environments adjacent to this complex and the socioeconomic profile of the local population that would be most vulnerable to this type of disaster. Vulnerability studies are essential as one of the first step in the development of an integrated coastal zone management. The variables analyzed in this study included geomorphological units, and the income, education, and dependence on fishing of the local population. The estimate of the vulnerability index was based on the relationships between these variables, which were used to generate a vulnerability map using GIS and the interpretation of high-resolution remote sensing, showing the areas of highest priority for intervention in the case of oil spills. The analysis of the natural and socioeconomic environments indicated that the areas of highest vulnerability correspond to the mangroves and the Vila Nova and Alto da Esperança neighborhoods, respectively. These neighborhoods have a direct relationship with fishing, and low levels of both income and education. By contrast, the lowest vulnerability was attributed to the coastal plateau and the central Anjo da Guarda neighborhood, which is occupied by residents with relatively high income and education, who do not depend on fishing.  相似文献   
527.
Despite more than 20 years of economic progress, especially in emerging economies like Brazil, the gap between developed and developing countries is still large, and environment problems have risen significantly. In this context, this paper aims to make the Brazilian furniture production cleaner, analyzing the environmental requirements considered by the micro and small enterprises (SMEs) in made-to-order furniture industry during the product development process (PDP). Another attempt was to identify the internal and external factors that led to the incorporation of these requirements. In this regard, a comprehensive review of eco-design concept that consists of composing environmental requirements into the PDP, through methods, tools, guidelines and techniques, was carried out. The data were collected using semi-structured interviews and in loco observations, analyzing each activity of the PDP and the environmental requirements on 18 SMEs in Brazil. The outcomes show that the economic factors determine the way in which the enterprises respond to the environmental issues and how adequate their companies according to laws and regulations. Moreover, the small number of qualified professionals in this field lead to difficulties to structure the sector, in other words, to produce with less environment impact.  相似文献   
528.
The Senegal sole, Solea senegalensis, is a species of flatfish that has several distinct cohorts of 0-group juveniles which use estuarine nurseries in summer and winter. The early cohort is more abundant and grows faster than the late cohort that stays in the nurseries during winter; however, climate warming may have an impact on the dynamics of this species’ juveniles. This study aimed to compare mortality, metabolic response and growth of S. senegalensis juveniles at different temperatures, reflecting present-day temperature (winter—12 °C; summer—24 °C) and future temperature (plus 3 °C) conditions, in estuarine nurseries in the southern European population. Mortality was low at 12 °C, being only 10 %, increasing to 30 % at 15 °C, 40 % at 24 °C and at 27 °C it hit 70 %. Metabolic rate increased steadily with increasing temperatures, yet it increased steeply from 24 to 27 °C. Thermal sensitivity was high for the temperature interval between 24 and 27 °C. Growth was very slow at 12 °C, at a rate of 0.03 mm day?1, increasing to 0.22 mm day?1 at 15 °C, and to 0.60 mm day?1, at 24 °C. However, at 27 °C growth rapidly declined to 0.12 mm day?1. Warming will be beneficial for the late cohort, resulting in a major increase in growth. However, the early cohort will not benefit from warming, due to high mortality and arrested growth, which clearly indicates that this species is under severe thermal stress at 27 °C. Thus, here we show, for the first time, that climate change may induce contrasting seasonal impacts on fish bio-ecology and physiology, namely in species with several cohorts over the course of the year. Phenotypic and/or genotypic plasticity may limit the impacts of climate change.  相似文献   
529.
This work analyzes the performance of an innovative biogas upgrading method, Alkali absorption with Regeneration (AwR) that employs industrial residues and allows to permanently store the separated CO2. This process consists in a first stage in which CO2 is removed from the biogas by means of chemical absorption with KOH or NaOH solutions followed by a second stage in which the spent absorption solution is contacted with waste incineration Air Pollution Control (APC) residues. The latter reaction leads to the regeneration of the alkali reagent in the solution and to the precipitation of calcium carbonate and hence allows to reuse the regenerated solution in the absorption process and to permanently store the separated CO2 in solid form. In addition, the final solid product is characterized by an improved environmental behavior compared to the untreated residues. In this paper the results obtained by AwR tests carried out in purposely designed demonstrative units installed in a landfill site are presented and discussed with the aim of verifying the feasibility of this process at pilot-scale and of identifying the conditions that allow to achieve all of the goals targeted by the proposed treatment. Specifically, the CO2 removal efficiency achieved in the absorption stage, the yield of alkali regeneration and CO2 uptake resulting for the regeneration stage, as well as the leaching behavior of the solid product are analyzed as a function of the type and concentration of the alkali reagent employed for the absorption reaction.  相似文献   
530.
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