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http://deepblue.lib.umich.edu/bitstream/2027.42/91015/1/aramaria_1334684899.pd

Selection of Representative Buildings through Preliminary Cluster Analysis

Nowadays the debate in Europe concerning the energy retrofit of existing buildings is oriented to the research of the most convenient retrofit actions from a technical and economic point of view. The methodology is a cost-optimal analysis of diverse retrofit improvements, which could be conducted on a representative reference building, as happens for the definition of the new law performance requisites. Defining a reference building in a sample, implies the analysis of a large amount of information. Many data mining algorithms can be used to find correlations and patterns. One of such techniques is clustering analysis, according to which a set is divided into several homogeneous groups whose elements have similar characteristics. The aim of this work is to explore the possibility of supporting the energy audit of a large building stock using few synthetic descriptors calculated for homogeneous groups found out by means of clustering. A group of 60 schools located in the North Italian province of Treviso has been analyzed. Metered energy consumptions and seasonal degree days were available for the last five year period. Regarding the schools’ geometrical features, the gross and net heated volume, the floor area, the window area, and the dispersing envelope surface are known. Moreover the thermal resistance of the building envelope components and the type of heating system are available. Energy and geometrical indicators have been calculated: the ratio between dispersing area and gross heated volume, the window to wall ratio, the energy consumption per volume unit and the energy per volume unit and degree day. In order to cluster the schools, the sets of parameters explaining the energy performance has been determined by considering the best multiple regressions between each possible group of parameters and total energy consumption. K-means cluster analysis has then performed on the school population considering the parameters in those sets. Two are the main issues to deal with in this analyis: the type and the most suitable number of parameters to be correlated to energy consumption and the suitable number of clusters to be determined. Concerning the first aspect, all parameters have been grouped in all the possible combination from 2 to 8 elements and a multiple linear regression was calculated for each single configuration set. The more numerous the set, the more precise is expected to be the correlation, but negligible changes in the coefficient of determination was shown for more than 6 parameters which seems to be an acceptable compromise between representativeness and complexity. As regards the second issue, the regression analysis has been repeated for each cluster found, to check if the correlations between the parameters and the energy consumption improves inside each cluster with respect to the whole sample. The number of clusters is expected to improve the correlation coefficient. In the paper optimization techniques have been applied to define the parameters and the minimum number of clusters that gives the best level of correlation

A new polyhedral approach to combinatorial designs

We consider combinatorial t-design problems as discrete optimization problems. Our motivation is that only a few studies have been done on the use of exact optimization techniques in designs, and that classical methods in design theory have still left many open existence questions. Roughly defined, t-designs are pairs of discrete sets that are related following some strict properties of size, balance, and replication. These highly structured relationships provide optimal solutions to a variety of problems in computer science like error-correcting codes, secure communications, network interconnection, design of hardware; and are applicable to other areas like statistics, scheduling, games, among others. We give a new approach to combinatorial t-designs that is useful in constructing t-designs by polyhedral methods. The first contribution of our work is a new result of equivalence of t-design problems with a graph theory problem. This equivalence leads to a novel integer programming formulation for t-designs, which we call GDP. We analyze the polyhedral properties of GDP and conclude, among other results, the associated polyhedron dimension. We generate new classes of valid inequalities to aim at approximating this integer program by a linear program that has the same optimal solution. Some new classes of valid inequalities are generated as Chv´atal-Gomory cuts, other classes are generated by graph complements and combinatorial arguments, and others are generated by the use of incidence substructures in a t-design. In particular, we found a class of valid inequalities that we call stable-set class that represents an alternative graph equivalence for the problem of finding a t-design. We analyze and give results on the strength of these new classes of valid inequalities. We propose a separation problem and give its integer programming formulation as a maximum (or minimum) edge-weight biclique subgraph problem. We implement a pure cutting-plane algorithm using one of the stronger classes of valid inequalities derived. Several instances of t-designs were solved efficiently by this algorithm at the root node of the search tree. Also, we implement a branch-and-cut algorithm and solve several instances of 2-designs trying different base formulations. Computational results are included

Influence of fundamental material properties and air void structure on moisture damage of asphalt mixes

Moisture damage in asphalt mixes refers to the loss of serviceability due to the presence of moisture. The extent of moisture damage, also called moisture susceptibility, depends on internal and external factors. The internal factors relate to the properties of the materials and the microstructure distribution, while the external factors include the environmental conditions, production and construction practices, pavement design, and traffic level. The majority of the research on moisture damage is based on the hypothesis that infiltration of surface water is the main source of moisture. Of the two other principal mechanisms of water transport, permeation of water vapor and capillary rise of subsurface water, the latter has been least explored. A laboratory test and analysis methods based on X-ray computed tomography (CT) were established to assess the capillary rise of water. The amount and size of air voids filled with water were used in the capillary rise equation to estimate the distribution of the contact angles between the water and the mastic. The results were able to show the influence of air void size on capillary rise and contact angles. The relationship between air void structure and moisture susceptibility was evaluated using a fundamental fracture model based on dissipated energy of viscoelastic materials. Detailed description is provided in this dissertation on the deduction of the model equation, the selection of the model parameters, and the required testing protocols. The model parameters were obtained using mechanical tests and surface energy measurements. The microstructure of asphalt mixes prepared in the laboratory having different air void structures was captured using X-ray CT, and image analysis techniques were used to quantify the air void structure and air void connectivity. The air void structure was found to influence the mix resistance to moisture damage. To validate the fracture model, asphalt mixes with known field performance were tested. The results demonstrated that the fracture model is an effective tool to characterize moisture susceptibility. In addition, the model showed good correlation with the reported field performance of the asphalt mixes. The findings of this study will be useful to highway engineers to evaluate asphalt mixes with alternative mix designs and internal air void structures and to estimate the rate of moisture infiltration in order to maximize the resistance of asphalt mixes to moisture damage

La Coloración de Gram en el Diagnóstico de la Infección Urinaria.

RESUMEN El propósito de este estudio, fue validar la coloración de Gram de la orina centrifugada con el método de cultivo cuantitativo con recuento de 105 unidades formadoras de colonia (UFC) / mL de orina, como prueba de referencia o ‘'gold standar´´, en muestras de personas a quienes se les solicitó urocultivo, para investigación de Infección del Tracto Urinario ( ITU ) en el Laboratorio Clínico de la Escuela de Bacteriología, Facultad de Salud de la UIS; el cual se realizó a partir de 601 muestras, en el periodo comprendido entre Enero del 2.001 a Marzo del 2.003. Las orinas se centrifugaron y el sedimento coloreado con Gram fue analizado microscopicamente, las muestras que presentaban bacterias fueron cultivadas en medios selectivos de acuerdo con la morfología y la tinción observada, aquellas en las que no se observaron bacterias no se cultivaron en ningún medio, pero si se hizo el recuento de bacterias. Mediante la coloración de Gram se encontró que de las 601 muestras analizadas, se obtuvo 165 (27.4%) positivas para bacterias de las cuales 149 (90.3%) mostraron bacilos Gram negativos, mientras solo 16 (9.7 %) presentaban cocos Gram positivos. Adicionalmente 161 ( 26.7 %) de las muestras positivas mostraron presencia de leucocitos. El 96.3 %( 155 ) de las muestras leucocito positivas presentaron recuentos entre 104 y 105 unidades formadora de colonia por mililitro de orina (UFC/ mL.). Obteniéndose con este trabajo que la sensibilidad de 93.9 % y una especificidad de 97.7% de la coloración de Gram en orina centrifugada, dado que en 436 del total de muestras no se observó bacterias ni leucocitos por tanto sus recuentos fueron negativos y en aquellas en las que se observaron bacterias y leucocitos se obtuvieron recuentos 105 UFC/mL que indicaban una infección urinaria con un solo tipo de bacteria. Palabras claves: Infección Urinaria. Gram. Piuria. Bacteriuria ABSTRACT The purpose of this work was to validate the Gram stain of centrifuged urine related in front of with the bacterium count by the cuantitative method, with count of bacterium = 105 CUF /mL of urine or "gold stand " in samples of persons from whom cultures were solicited the urine culture in the Laboratory of Clinic Escuela de Bacteriología Facultad de Salud de la UIS, the present study was carried out to determine the degree of reliability and sensitivity of the Gram method for the diagnosis of Urinary infection (UIT) beginning at the 601 samples of urine in the period understood to be between January 2001 and March 2003. The urine was centrifuged and the sediment was microscopically analyzed by Gram stain end the samples that showed bacteria were cultivated in selective mediums in accordance with the morphology and observed dyes, those in which bacteria was not observed were not cultivated by any medium, but they had a bacteria count. During the Gram stain it was found that of the 601 analyzed samples, 165 ( 27.4 %) showed positive for bacteria and of those 149 ( 90.3 %) showed Gram negative bacillus, while only 16 ( 9.7 % ) Gram positive cocci. Additionally 161 26.7 %) of the positive samples showed rhe presence of leukocites. The 96.3 % (155) of the positive leukocite samples showed counts between 104 and 105 UFC /mL. In conclusion this work, the sensitivity was 93.0 % and specificity 97.7% of Gram stain in centrifuged urine , given that in 436 of the total samples neither bacterias nor leukocites were observed for as much as their counts were negative and in those that bacterias and leukocites were observed they displayed counts of 105 UFC/ mL that indicated a urinary infection with only one type of bacteria.  keys words : Urinary infections. Gram. piuria. bacteriuri

La Coloración de Gram en el Diagnóstico de la Infección Urinaria.

RESUMEN El propósito de este estudio, fue validar la coloración de Gram de la orina centrifugada con el método de cultivo cuantitativo con recuento de 105 unidades formadoras de colonia (UFC) / mL de orina, como prueba de referencia o ‘'gold standar´´, en muestras de personas a quienes se les solicitó urocultivo, para investigación de Infección del Tracto Urinario ( ITU ) en el Laboratorio Clínico de la Escuela de Bacteriología, Facultad de Salud de la UIS; el cual se realizó a partir de 601 muestras, en el periodo comprendido entre Enero del 2.001 a Marzo del 2.003. Las orinas se centrifugaron y el sedimento coloreado con Gram fue analizado microscopicamente, las muestras que presentaban bacterias fueron cultivadas en medios selectivos de acuerdo con la morfología y la tinción observada, aquellas en las que no se observaron bacterias no se cultivaron en ningún medio, pero si se hizo el recuento de bacterias. Mediante la coloración de Gram se encontró que de las 601 muestras analizadas, se obtuvo 165 (27.4%) positivas para bacterias de las cuales 149 (90.3%) mostraron bacilos Gram negativos, mientras solo 16 (9.7 %) presentaban cocos Gram positivos. Adicionalmente 161 ( 26.7 %) de las muestras positivas mostraron presencia de leucocitos. El 96.3 %( 155 ) de las muestras leucocito positivas presentaron recuentos entre 104 y 105 unidades formadora de colonia por mililitro de orina (UFC/ mL.). Obteniéndose con este trabajo que la sensibilidad de 93.9 % y una especificidad de 97.7% de la coloración de Gram en orina centrifugada, dado que en 436 del total de muestras no se observó bacterias ni leucocitos por tanto sus recuentos fueron negativos y en aquellas en las que se observaron bacterias y leucocitos se obtuvieron recuentos 105 UFC/mL que indicaban una infección urinaria con un solo tipo de bacteria. Palabras claves: Infección Urinaria. Gram. Piuria. Bacteriuria ABSTRACT The purpose of this work was to validate the Gram stain of centrifuged urine related in front of with the bacterium count by the cuantitative method, with count of bacterium = 105 CUF /mL of urine or "gold stand " in samples of persons from whom cultures were solicited the urine culture in the Laboratory of Clinic Escuela de Bacteriología Facultad de Salud de la UIS, the present study was carried out to determine the degree of reliability and sensitivity of the Gram method for the diagnosis of Urinary infection (UIT) beginning at the 601 samples of urine in the period understood to be between January 2001 and March 2003. The urine was centrifuged and the sediment was microscopically analyzed by Gram stain end the samples that showed bacteria were cultivated in selective mediums in accordance with the morphology and observed dyes, those in which bacteria was not observed were not cultivated by any medium, but they had a bacteria count. During the Gram stain it was found that of the 601 analyzed samples, 165 ( 27.4 %) showed positive for bacteria and of those 149 ( 90.3 %) showed Gram negative bacillus, while only 16 ( 9.7 % ) Gram positive cocci. Additionally 161 26.7 %) of the positive samples showed rhe presence of leukocites. The 96.3 % (155) of the positive leukocite samples showed counts between 104 and 105 UFC /mL. In conclusion this work, the sensitivity was 93.0 % and specificity 97.7% of Gram stain in centrifuged urine , given that in 436 of the total samples neither bacterias nor leukocites were observed for as much as their counts were negative and in those that bacterias and leukocites were observed they displayed counts of 105 UFC/ mL that indicated a urinary infection with only one type of bacteria.  keys words : Urinary infections. Gram. piuria. bacteriuri

Identification and quantification of pathogenic helminth eggs using a digital image system

AbstractA system was developed to identify and quantify up to seven species of helminth eggs (Ascaris lumbricoides -fertile and unfertile eggs-, Trichuris trichiura, Toxocara canis, Taenia saginata, Hymenolepis nana, Hymenolepis diminuta, and Schistosoma mansoni) in wastewater using different image processing tools and pattern recognition algorithms. The system was developed in three stages. Version one was used to explore the viability of the concept of identifying helminth eggs through an image processing system, while versions 2 and 3 were used to improve its efficiency. The system development was based on the analysis of different properties of helminth eggs in order to discriminate them from other objects in samples processed using the conventional United States Environmental Protection Agency (US EPA) technique to quantify helminth eggs. The system was tested, in its three stages, considering two parameters: specificity (capacity to discriminate between species of helminth eggs and other objects) and sensitivity (capacity to correctly classify and identify the different species of helminth eggs). The final version showed a specificity of 99% while the sensitivity varied between 80 and 90%, depending on the total suspended solids content of the wastewater samples. To achieve such values in samples with total suspended solids (TSS) above 150 mg/L, it is recommended to dilute the concentrated sediment just before taking the images under the microscope. The system allows the helminth eggs most commonly found in wastewater to be reliably and uniformly detected and quantified. In addition, it provides the total number of eggs as well as the individual number by species, and for Ascaris lumbricoides it differentiates whether or not the egg is fertile. The system only requires basically trained technicians to prepare the samples, as for visual identification there is no need for highly trained personnel. The time required to analyze each image is less than a minute. This system could be used in central analytical laboratories providing a remote analysis service