Metodologia de implantação da construção enxuta: estudo de caso em construtora de porte médio

In recent years, the Brazilian construction industry has gone by changes like currency stability, increasing competition, shortage of skilled labor and increasing quality importance required by the customer, who made the sector companies seek solutions through new management practices in order to become more efficient. A alternative to these management practices is known as Lean Construction which is derived from the Toyota System Production. Lean Construction main goals are to reduce parts of activities that do not add value, increase product value by considering customer needs, reduce variability and production cycle time, simplify process by reducing the number of parts or steps, increase the flexibility in the product execution and transparency process, focus the control on overall process, introduce continuous improvement process, maintain a balance between improvements in flows and conversions and seek to learn from practices adopted by competitors. However, the construction industry is characterized by having nomadic activity, which undertakes an unique product with high cost of production and big inertia for behavioral change, making it difficult to implement the philosophy of lean construction in companies. In this sense, the main objective of this study is to develop a methodology for implementation of the principles of Lean Construction. The method of implementing the proposed management system was designed with the aid of 5W2H tool, and the implementation process is divided into three phases. The first one aims to know in a macro way the current operation of construction, identify who is its target audience and what are the products and services offered to the Market. The second phase aims to describe what actions should be taken and which documents are needed to be created or modified; finally, the third step goal consists in how to control and monitor established processes, where through Strategic Planning the company goals would be set along with their respective targets and indicators in order to keep the system working, aiming for continuous improvement with focus on the customer. This methodology was conceived as a case study analyzing a medium size construction with more than 18 years of activity and certified for almost 10 years with ISO9001 and level A in PBQP-H. We also conclude that this implementation process can be used in any developer and / or builder

Uma proposta para preparação de pequenas e médias empresas brasileiras prestadoras de serviços ao setor de telecomunicações para implantação da metodologia Seis Sigma

The objective of this work consists of considering a script so that operating companies in the telecommunications sector, mainly small and medium-sized enterprises, can reach excellency in its operations and get, thus, conditions to compete with companies consolidated in its niche of market. The proposal intends to lead the enterprises to a level of qualification of processes that to become them apt to adopt the Six Sigma method as part of its culture. From the analysis of the essential processes of the sector, methods and tools will be suggested for guarantee the continuous improvement of these processes, without forgetting the internal peculiarities of each company

Seis sigma :uma proposta para implementação da metodologia em pequenas e médias empresas

The Six Sigma methodology consists of a program guided to the continuous improvement of enterprise processes, which aims at customer satisfaction, as well as increasing financial and operational profits. Considering that more than 99% of the Brazilian companies have up to five hundred employees, this study investigates how Six Sigma can be applied in small or medium size companies. This study was conducted based on literature review and application of the ideas in a medium size newspaper company, which manufactures newspapers that circulate daily in the state of Rio Grande do Norte. The results of the research point to the viability of use of the methodology in this market segment, as well as suggest a method that can be used in similar companies

Impactos da certificação ISO 9000 no desempenho estratégico :um estudo em empresas brasileiras do setor químico

This thesis deals with analyzing the contribution grade of the ISO 9000 quality system to the strategic performance of the Brazilian firms in the Chemistry sector, using the Balanced Scorecard system as reference. An exploratory research is developed to get technical information about these two management systems, with emphasis in their integration. After, a quantitative research is implemented using a questionnaire, to know and to obtain necessaries data for improving statistical estimations of the multiple relationships between the variables and the strategic performance for the universe of 352 Brazilians firms that make use of ISO 9000 as quality system. The size of the sample totalized 111 firms, which represent more than 31% of the selected universe. The main results show different visions of directors and managers about the significant variables that contribute for the strategic performance of the analyzed firms. The ISO 9000 system presents a big contribution to the strategic performance, when referred by the four perspectives of the Balanced Scorecard: learning and growth; internal process; customer and financial. Better performance was verified in the learning and growth perspective and reasonable performance was verified in the financial perspective

Melhoria de desempenho e ISO 9000: um estudo em empresas brasileiras do setor hoteleiro na perspectiva do Balanced Scorecard

This Thesis deals with the performance improvement on hotels that have adopted the ISO 9000 Quality Management Systems. It is researched the Brazilian hotels that have an ISO 9001 registration with an assessment form based on the Balanced Scorecard approach. The main findings are that ISO 9000 provided improvement on the performance of the hotels in general and also in all the BSC perspectives, and that are different perception on managers and directors, what suggests a need for a tool like BSC to register the performance improvements on the same basis. The Thesis contributes to provide information on the performance improvement in hotels, one of the claimed regarding the low ISO 9000 adoption rate in Brazilian hotels

Caracterização espectral da água do reservatório de Itupararanga, SP, a partir de imagens hiperespectrais hyperion e análise derivativa

The current accessibility to hyperspectral images of Hyperion/EO1 orbital sensor has brought new perspectives for studies of aquatic environments for allowing the remote estimative of several optically active constituents (OACs) in water body. The changes in the composition and concentration of OACs cause different patterns of absorption and scattering of electromagnetic radiation, likely to be detected using hyperspectral data. Therefore, an investigation was conducted taking into account the spectral characterization of water of a reservoir intended for public supply (Itupararanga Reservoir), from Hyperion/EO1 images and derivative analysis technique applied to spectral curves generated. Simultaneously to the acquisition of a Hyperion/EO1 image, a field campaign was carried out to collect limnological data in situ in georeferenced points. After radiometric correction of the image, reflectance curves of pixels were extracted for each station and the curves obtained were subjected to the technique of derivative analysis, which revealed features of absorption and scattering mainly associated to the presence of algal pigments. The results obtained show the presence of phytoplankton and algal activity, matching the field observation.

Análise de séries temporais de coordenadas estimadas com GPS: uma proposta metodológica para detecção, remoção e recuperação de efeitos sazonais

GPS active networks are more and more used in geodetic surveying and scientific experiments, as water vapor monitoring in the atmosphere and lithosphere plate movement. Among the methods of GPS positioning, Precise Point Positioning (PPP) has provided very good results. A characteristic of PPP is related to the modeling and/or estimation of the errors involved in this method. The accuracy obtained for the coordinates can reach few millimeters. Seasonal effects can affect such accuracy if they are not consistent treated during the data processing. Coordinates time series analyses have been realized using Fourier or Harmonics spectral analyses, wavelets, least squares estimation among others. An approach is presented in this paper aiming to investigate the seasonal effects included in the stations coordinates time series. Experiments were carried out using data from stations Manaus (NAUS) and Fortaleza (BRFT) which belong to the Brazilian Continuous GPS Network (RBMC). The coordinates of these stations were estimated daily using PPP and were analyzed through wavelets for identification of the periods of the seasonal effects (annual and semi-annual) in each time series. These effects were removed by means of a filtering process applied in the series via the least squares adjustment (LSQ) of a periodic function. The results showed that the combination of these two mathematical tools, wavelets and LSQ, is an interesting and efficient technique for removal of seasonal effects in time series.

Acurácia e precisão: revendo os conceitos de forma acurada

Accuracy concepts that involve systematic and random effects and precision, that involves only random ones, are reviewed in this paper. An objective discussion is presented based on the definitions that appear in the literature, followed by examples that may be enough to clarify some concepts and allow the extension for other applications. The discussion presented aims at raising eventual inconsistencies in the interpretations so as to provide better possibilities of use for those involved with this topic, which is fundamentally important in the quality analysis of cartographic, geodetic and remote sensing or photogrammetric products.

Modelagem de distorções entre sad 69 e sirgas 2000 pelo método de shepard e grades regulares

Brazil follows the tendency of some countries to update and/or review their fundamental geodetic network. The adoption of geocentric referentials like SIRGAS 2000, the new official reference system of the Geodetic Brazilian System has been an advance. Changes in referential implies in coordinates changes on the network stations as well as the network geometry. To make use of analogical and digital products which are already known in the old referentials are necessary approaches to the coordinate conversion, which minimize the distortions between the used reference frames. This paper presents a distortion modeling approach between reference frames, based on distortion grid generation by using the Shepard's method. To analyze the approach some experiments were performed with the generation of a 1 degrees x1 degrees distortion grid to model the distortions between SAD 69 (1996) and SIRGAS (2000) frames. The results in the test stations were promising, with an average reduction of 50% in the RMS coordinates after the distortions modeling.

Análise do modelo troposférico empregado na geração de uma estação de referência virtual utilizando o posicionamento por ponto preciso

In the past few years the interest is accomplishing a high accuracy positioning increasing. One of the methods that has been applied by the scientific community is the network based on positioning. By using multiple reference station data, it is possible to obtain centimetric positioning in a larger coverage area, in addition to gain in reliability, availability and integrity of the service. Besides, using this concept, it is possible to model the atmospheric effects (troposphere refraction and ionosphere effect). Another important question concerning this topic is related to the transmission of the network corrections to the users. There are some possibilities for this fact and an efficient one is the Virtual Reference Station (VRS) concept. In the VRS concept, a reference station is generated near to the rover receiver (user). This provides a short baseline and the user has the possibility of using a single frequency receiver to accomplish the relative positioning. In order to test this kind of positioning method, a software has been developed at São Paulo State University. In this paper, the methodology applied to generate the VRS data is described and the VRS quality is analyzed by using the Precise Point Positioning (PPP) method.

Período de mínima atividade solar: melhora no desempenho do posicionamento relativo

In the relative positioning, even considering that part of the errors due to ionosphere is canceled with the double-difference observations, strong ionospheric effects can occur in maximum solar activity period. However, in minimum solar activity period, the ionospheric effects decrease significantly and therefore an improvement of the relative positioning performance takes place. In this paper we aim at showing that improvement for the scientific and GPS community users. So, have been experiments by using GPS data of two stations of the Brazilian Network for Continuous Monitoring of GPS, forming a baseline of 430 km. The processing were use accomplished with interval of two hours, and only L1 carrier data have been used. The analysis of the obtained results has been carried out from the discrepancies between the "true" coordinates and corresponding ones obtained in the processing. In maximum solar activity period the discrepancy value reached 25 m. on the other hand, in minimum solar activity period, the discrepancy value reached 5,5 m. It is important to emphasize that the majority of the discrepancy values didn't exceed 0,50 m, and in some cases only reached 0,10 m. This shows the increase of application possibilities of the relative positioning using single-frequency GPS receivers in minimum solar activity period.

Extração de feições retas com precisão subpixel: estudo comparativo entre três métodos

In the fields of Machine Vision and Photogrammetry, extracted straight lines from digital images can be used either as vector elements of a digital representation or as control entities that allow the determination of the camera interior and exterior orientation parameters. Applications related with image orientation require feature extraction with subpixel precision, to guarantee the reliability of the estimated parameters. This paper presents three approaches for straight line extraction with subpixel precision. The first approach considers the subpixel refinement based on the weighted average of subpixel positions calculated on the direction perpendicular to the segmented straight line. In the second approach, a parabolic function is adjusted to the grey level profile of neighboring pixels in a perpendicular direction to the segmented line, followed by an interpolation of this model to estimate subpixel coordinates of the line center. In the third approach, the subpixel refinement is performed with a parabolic surface adjustment to the grey level values of neighboring pixels around the segmented line. The intersection of this surface with a normal plane to the line direction generates a parabolic equation that allows estimating the subpixel coordinates of the point in the straight line, assuming that this is the critical point of this function. Three experiments with real images were made and the approach based on parabolic surface adjustment has presented better results.

Extração automática de contornos de telhados usando dados de varredura a laser e campos randômicos de Markov

This paper proposes a methodology for automatic extraction of building roof contours from a Digital Elevation Model (DEM), which is generated through the regularization of an available laser point cloud. The methodology is based on two steps. First, in order to detect high objects (buildings, trees etc.), the DEM is segmented through a recursive splitting technique and a Bayesian merging technique. The recursive splitting technique uses the quadtree structure for subdividing the DEM into homogeneous regions. In order to minimize the fragmentation, which is commonly observed in the results of the recursive splitting segmentation, a region merging technique based on the Bayesian framework is applied to the previously segmented data. The high object polygons are extracted by using vectorization and polygonization techniques. Second, the building roof contours are identified among all high objects extracted previously. Taking into account some roof properties and some feature measurements (e. g., area, rectangularity, and angles between principal axes of the roofs), an energy function was developed based on the Markov Random Field (MRF) model. The solution of this function is a polygon set corresponding to building roof contours and is found by using a minimization technique, like the Simulated Annealing (SA) algorithm. Experiments carried out with laser scanning DEM's showed that the methodology works properly, as it delivered roof contours with approximately 90% shape accuracy and no false positive was verified.

Morfologia matemática aplicada à detecção de sombras e nuvens em imagens de alta resolução

The spatial resolution improvement of orbital sensors has broadened considerably the applicability of their images in solving urban areas problems. But as the spatial resolution improves, the shadows become even a more serious problem especially when detailed information (under the shadows) is required. Besides those shadows caused by buildings and houses, clouds projected shadows are likely to occur. In this case there is information occlusion by the cloud in association with low illumination and contrast areas caused by the cloud shadow on the ground. Thus, it's important to use efficient methods to detect shadows and clouds areas in digital images taking in count that these areas care for especial processing. This paper proposes the application of Mathematical Morphology (MM) in shadow and clouds detection. Two parts of a panchromatic QuickBird image of Cuiab-MT urban area were used. The proposed method takes advantage of the fact that shadows (low intensity - dark areas) and clouds (high intensity - bright areas) represent the bottom and top, respectively, of the image as it is thought to be a topographic surface. This characteristic allowed MM area opening and closing operations to be applied to reduce or eliminate the bottom and top of the topographic surface.

Método monoscópico para a determinação automática da altura de edifícios em fotografias aéreas

This paper proposes a monoscopic method for automatic determination of building's heights in digital photographs areas, based on radial displacement of points in the plan image and geometry at the time the photo is obtained. Determination of the buildings' heights can be used to model the surface in urban areas, urban planning and management, among others. The proposed methodology employs a set of steps to detect arranged radially from the system of photogrammetric coordinates, which characterizes the lateral edges of buildings present in the photo. In a first stage is performed the reduction of the searching area through detection of shadows projected by buildings, generating sub-images of the areas around each of the detected shadow. Then, for each sub-image, the edges are automatically extracted, and tests of consistency are applied for it in order to be characterized as segments of straight arranged radially. Next, with the lateral edges selected and the knowledge of the flight height, the buildings' heights can be calculated. The experimental results obtained with real images showed that the proposed approach is suitable to perform the automatic identification of the buildings height in digital images.