Manufacturing and assembly automation by integrated metrology systems for aircraft wing fabrication

Discrepancies of materials, tools, and factory environments, as well as human intervention, make variation an integral part of the manufacturing process of any component. In particular, the assembly of large volume, aerospace parts is an area where significant levels of form and dimensional variation are encountered. Corrective actions can usually be taken to reduce the defects, when the sources and levels of variation are known. For the unknown dimensional and form variations, a tolerancing strategy is typically put in place in order to minimize the effects of production inconsistencies related to geometric dimensions. This generates a challenging problem for the automation of the corresponding manufacturing and assembly processes. Metrology is becoming a major contributor to being able to predict, in real time, the automated assembly problems related to the dimensional variation of parts and assemblies. This is done by continuously measuring dimensions and coordinate points, focusing on the product's key characteristics. In this paper, a number of metrology focused activities for large-volume aerospace products, including their implementation and application in the automation of manufacturing and assembly processes, are reviewed. This is done by using a case study approach within the assembly of large-volume aircraft wing structures.

Nonparametric Estimation in the Class of Bisexual Processes with Population-Size Dependent Mating

2000 Mathematics Subject Classification: 60J80, 62M05

A Computational Approach for the Statistical Estimation of Discrete Time Branching Processes with Immigration

2010 Mathematics Subject Classification: 60J80.

Projected sequential Gaussian processes:a C++ tool for interpolation of large datasets with heterogeneous noise

Heterogeneous datasets arise naturally in most applications due to the use of a variety of sensors and measuring platforms. Such datasets can be heterogeneous in terms of the error characteristics and sensor models. Treating such data is most naturally accomplished using a Bayesian or model-based geostatistical approach; however, such methods generally scale rather badly with the size of dataset, and require computationally expensive Monte Carlo based inference. Recently within the machine learning and spatial statistics communities many papers have explored the potential of reduced rank representations of the covariance matrix, often referred to as projected or fixed rank approaches. In such methods the covariance function of the posterior process is represented by a reduced rank approximation which is chosen such that there is minimal information loss. In this paper a sequential Bayesian framework for inference in such projected processes is presented. The observations are considered one at a time which avoids the need for high dimensional integrals typically required in a Bayesian approach. A C++ library, gptk, which is part of the INTAMAP web service, is introduced which implements projected, sequential estimation and adds several novel features. In particular the library includes the ability to use a generic observation operator, or sensor model, to permit data fusion. It is also possible to cope with a range of observation error characteristics, including non-Gaussian observation errors. Inference for the covariance parameters is explored, including the impact of the projected process approximation on likelihood profiles. We illustrate the projected sequential method in application to synthetic and real datasets. Limitations and extensions are discussed. © 2010 Elsevier Ltd.

Development of a technological innovation capability assessment model:a case study of manufacturing SMEs in Sialkot, Pakistan

Small and Medium Enterprises (SMEs) play an important part in the economy of any country. Initially, a flat management hierarchy, quick response to market changes and cost competitiveness were seen as the competitive characteristics of an SME. Recently, in developed economies, technological capabilities (TCs) management- managing existing and developing or assimilating new technological capabilities for continuous process and product innovations, has become important for both large organisations and SMEs to achieve sustained competitiveness. Therefore, various technological innovation capability (TIC) models have been developed at firm level to assess firms‘ innovation capability level. These models output help policy makers and firm managers to devise policies for deepening a firm‘s technical knowledge generation, acquisition and exploitation capabilities for sustained technological competitive edge. However, in developing countries TCs management is more of TCs upgrading: acquisitions of TCs from abroad, and then assimilating, innovating and exploiting them. Most of the TIC models for developing countries delineate the level of TIC required as firms move from the acquisition to innovative level. However, these models do not provide tools for assessing the existing level of TIC of a firm and various factors affecting TIC, to help practical interventions for TCs upgrading of firms for improved or new processes and products. Recently, the Government of Pakistan (GOP) has realised the importance of TCs upgrading in SMEs-especially export-oriented, for their sustained competitiveness. The GOP has launched various initiatives with local and foreign assistance to identify ways and means of upgrading local SMEs capabilities. This research targets this gap and developed a TICs assessment model for identifying the existing level of TIC of manufacturing SMEs existing in clusters in Sialkot, Pakistan. SME executives in three different export-oriented clusters at Sialkot were interviewed to analyse technological capabilities development initiatives (CDIs) taken by them to develop and upgrade their firms‘ TCs. Data analysed at CDI, firm, cluster and cross-cluster level first helped classify interviewed firms as leader, follower and reactor, with leader firms claiming to introduce mostly new CDIs to their cluster. Second, the data analysis displayed that mostly interviewed leader firms exhibited ‗learning by interacting‘ and ‗learning by training‘ capabilities for expertise acquisition from customers and international consultants. However, these leader firms did not show much evidence of learning by using, reverse engineering and R&D capabilities, which according to the extant literature are necessary for upgrading existing TIC level and thus TCs of firm for better value-added processes and products. The research results are supported by extant literature on Sialkot clusters. Thus, in sum, a TIC assessment model was developed in this research which qualitatively identified interviewed firms‘ TIC levels, the factors affecting them, and is validated by existing literature on interviewed Sialkot clusters. Further, the research gives policy level recommendations for TIC and thus TCs upgrading at firm and cluster level for targeting better value-added markets.

Understanding and improving the manufacturing and changeover process in Saudi Arabian business - a multiple case study approach

The importance of the changeover process in the manufacturing industry is becoming widely recognised. Changeover is a complete process of changing between the manufacture of one product to manufacture of an alternative product until specified production and quality rates are reached. The initiatives to improve changeover exist in industry, as better changeover process typically contribute to improved quality performance. A high-quality and reliable changeover process can be achieved through implementation of continuous or radical improvements. This research examines the changeover process of Saudi Arabian manufacturing firms because Saudi Arabia’s government is focused on the expansion of GDP and increasing the number of export manufacturing firms. Furthermore, it is encouraging foreign manufacturing firms to invest within Saudi Arabia. These initiatives, therefore, require that Saudi manufacturing businesses develop the changeover practice in order to compete in the market and achieve the government’s objectives. Therefore, the aim of this research is to discover the current status of changeover process implementation in Saudi Arabian manufacturing businesses. To achieve this aim, the main objective of this research is to develop a conceptual model to understand and examine the effectiveness of the changeover process within Saudi Arabian manufacturing firms, facilitating identification of those activities that affect the reliability and high-quality of the process. In order to provide a comprehensive understanding of this area, this research first explores the concept of quality management and its relationship to firm performance and the performance of manufacturing changeover. An extensive body of literature was reviewed on the subject of lean manufacturing and changeover practice. A research conceptual model was identified based on this review, and focus was on providing high-quality and reliable manufacturing changeover processes during set-up in a dynamic environment. Exploratory research was conducted in sample Saudi manufacturing firms to understand the features of the changeover process within the manufacturing sector, and as a basis for modifying the proposed conceptual model. Qualitative research was employed in the study with semi-structured interviews, direct observations and documentation in order to understand the real situation such as actual daily practice and current status of changeover process in the field. The research instrument, the Changeover Effectiveness Assessment Tool (CEAT) was developed to evaluate changeover practices. A pilot study was conducted by examining the CEAT, proposed for the main research. Consequently, the conceptual model was modified and CEAT was improved in response to the pilot study findings. Case studies have been conducted within eight Saudi manufacturing businesses. These case studies assessed the implementation of manufacturing changeover practice in the lighting and medical products sectors. These two sectors were selected based on their operation strategy which was batch production as well as the fact that they fulfilled the research sampling strategy. The outcomes of the research improved the conceptual model, ultimately to facilitate the firms’ adoption and rapid implementation of a high-quality and reliability changeover during the set-up process. The main finding of this research is that Quality’s factors were considering the lowest levels comparing to the other factors which are People, Process and Infrastructure. This research contributes to enable Saudi businesses to implement the changeover process by adopting the conceptual model. In addition, the guidelines for facilitating implementation were provided in this thesis. Therefore, this research provides insight to enable the Saudi manufacturing industry to be more responsive to rapidly changing customer demands.

Exploring the biological basis for Salmonella persistence in food manufacturing environments

The persistence of Salmonella spp. in low moisture foods is a challenge for the food industry as despite control strategies already in place, notable outbreaks still occur. The aim of this study was to characterise isolates of Salmonella, known to be persistent in the food manufacturing environment, by comparing their microbiological characteristics with a panel of matched clinical and veterinary isolates. The gross morphology of the challenge panel was phenotypically characterised in terms of cellular size, shape and motility. In all the parameters measured, the factory isolates were indistinguishable from the human, clinical and veterinary strains. Further detailed metabolic profiling was undertaken using the biolog Microbial ID system. Multivariate analysis of the metabolic microarray revealed differences in metabolism of the factory isolate of S.Montevideo, based on its upregulated ability to utilise glucose and the sugar alcohol groups. The remainder of the serotype-matched isolates were metabolically indistinguishable. Temperature and humidity are known to influence bacterial survival and through environmental monitoring experimental parameters were defined. The results revealed Salmonella survival on stainless steel was affected by environmental temperatures that may be experienced in a food processing environment; with higher survival rates (D25=35.4) at temperatures at 25°C and lower humidity levels of 15% RH, however a rapid decline in cell count (D10=3.4) with lower temperatures of 10°C and higher humidity of 70% RH. Several resident factories strains survived in higher numbers on stainless steel (D25=29.69) compared to serotype matched clinical and veterinary isolates (D25=22.98). Factory isolates of Salmonella did not show an enhanced growth rate in comparison to serotype matched solates grown in Luria broth, Nutrient broth and M9 minimal media indicating that as an independent factor, growth was unlikely to be a major factor driving Salmonella persistence. Using a live / dead stain coupled with fluorescence microscopy revealed that when no longer culturable, isolates of S.Schwarzengrund entered into a viable nonculturable state. The biofilm forming capacity of the panel was characterised and revealed that all were able to form biofilms. None of the factory isolates showed an enhanced capability to form biofilms in comparison to serotype-matched isolates. In disinfection studies, planktonic cells were more susceptible to disinfectants than cells in biofilm and all the disinfectants tested were successful in reducing bacterial load. Contact time was one of the most important factors for reducing bacterial populations in a biofilm. The genomes of eight strains were sequenced. At the nucleotide and amino acid level the food factory isolates were similar to those of isolates from other environments; no major genomic rearrangements were observed, supporting the conclusions of the phenotypic and metabolic analysis. In conclusion, having investigated a variety of morphological, biochemical and genomic factors, it is unlikely that the persistence of Salmonella in the food manufacturing environment is attributable to a single phenotypic, metabolic or genomic factor. Whilst a combination of microbiological factors may be involved it is also possible that strain persistence in the factory environment is a consequence of failure to apply established hygiene management principles.

Szolgáltatásmenedzsment Magyarországon a termelő- és a szolgáltatóvállalatoknál (Service management at the manufacturing and service companies in Hungary)

A szolgáltatási tevékenységek ma már döntő szerepet játszanak a gazdaságok működésében, nemcsak az egyre nagyobb arányt képviselő szolgáltatószektorban, hanem a termelővállalatoknál is. Ez a tanulmány – a szolgáltatásmenedzsment néhány elfogadott tételének felhasználásával – azt vizsgálja, hogy a Budapesti Corvinus Egyetem Versenyképesség Kutató Központja által szervezett versenyképesség-kutatás 3. fordulójának adatai alapján mit tudunk mondani ma Magyarországon a szolgáltatásokról. Fő megállapításai szerint hazánkban a termelővállalatok ma felkészültebbek a szolgáltatások nyújtása terén, mint maguk a szolgáltatók. Erőfeszítéseiket nemcsak a szolgáltatásminőség javítására, hanem a szolgáltatásnyújtási folyamat fejlesztésére is fordítják. A nagyobb erőfeszítés pedig erőteljesebb hatást gyakorol a vállalatok jövedelmezőségére és a vevői érték növekedésére egyaránt. ______ Service activities nowadays play a crucial role in developed economies. This statement is true not only in the ever increasing service sector, but also at manufacturing companies. This study gives a picture about services in the Hungarian economy on the basis of the 3rd round competitiveness survey organized by the Competitiveness Research Centre of Corvinus University of Budapest. Some hypotheses based on classical service management issues are tested. According to the most important conclusions, manufacturing companies in Hungary are more prepared today to provide services than the service sector itself. Manufacturing companies put efforts both into improving service quality and processes. And these efforts appear in increasing profitability and customer value.

Az SAP-rendszer fejlesztése egy műanyag-feldolgozó vállalatnál (Development of SAP system in a plastic manufacturing company)

Az SAP-rendszernek a kontrollingszervezetek működésére gyakorolt pozitív hatása nem titok. A visszacsatolás lehetőségének biztosításával alkalom nyílik a szervezetek tevékenységének követésére, ellenőrzésére, felülbírálására. A logisztika mint az egész vállalatot átszövő rendszer, működésének nyomon követése is létfontosságúvá vált, hiszen összetettségéből kifolyólag jellegzetességei, színvonala az egész rendszerre hatást gyakorol. A logisztikai rendszer és folyamatainak figyelemmel kísérésére a logisztikai kontrollingrendszer nyújt megoldást, visszacsatolási pontjain keresztül. A műanyag-feldolgozó vállalat esetében a szervezeti SAP-rendszer logisztikai kontrollingterületének fejlesztésétől várják a szervezeti hatékonyság emelkedését és a jobb színvonal elérését. _____ Positive effect of the SAP system on the operation of controlling organisations has not been a secret. Opportunity of the feedback will be possible to track, control, override operation of the organisations. The logistic controlling system provides a solution through feedback points for monitoring the logistic system and processes. In the case of plastics manufacturing company the increasing of organisational efficiency and achievement of a better standard is anticipated from development of logistic controlling area of the organisational SAP system.

Estudo comparativo da capacidade de assamento de dois fornos solares com diferentes configurações

This research is presented as a comparative study about the baking capacity of two box type ovens, produced from a packing case used to equipment transportation. The two ovens have different internal settings, with the greenhouse effect and the concentration of incident solar radiation as the main parameters of differentiation. The main features of the ovens are the low cost, the reuse of materials, the manufacturing and assembly processes simplified, the easy management and the ability of baking a variety of foods simultaneously. The manufacturing and operation of the ovens can be handled by any social and intellectual level of people. The feasibility of the ovens to bake the tested foods was proved with success, ensuring the supremacy of the mirrored oven. The results obtained for both ovens were competitive even with the conventional gas oven, producing the baking of three cakes with 750g in just 80 minutes.

Short-term temporal and spatial variations in physical, optical and biogeochemical parameters in June of 2013 in Alfacs Bay (NW Mediterranean)

With the aim of analyzing the complex physical and biogeochemical interactions at high temporal and spatial resolution in the complex estuarine waters of Alfacs Bay, a beam attenuation-based approach was used as optical proxy of different biogeochemical variables. Thus, the dataset contains the attenuation proxies as well as laboratory results from the analysis of water samples, which were used to validate our approach. In addition, the major physical forcing in the Bay was also measured.

Geochemical parameters of sediments and waters in areas of ocean barrier zones

Geochemical barrier zones play an important role in determining various physical systems and characteristics of oceans, e.g. hydrodynamics, salinity, temperature and light. In the book each of more than 30 barrier zones are illustrated and defined by physical, chemical and biological parameters. Among the topics discussed are processes of inflow, transformation and precipitation of the sedimentary layer of the open oceans and more restricted areas such as the Baltic, Black and Mediterranean Seas.

Geochemical and biogeochemical parameters of Black Sea waters and suspended matter

The monograph focuses on the analysis of data addressing the problem of H2S contamination and oxic-anoxic interface in the Black Sea. Regularities of the fine structure of vertical distribution of oxygen, hydrogen sulfide, biogenic elements, organic substances, suspended matter, and metals of the iron-manganese group in the area of contact of aerobic and anaerobic waters have been revealed. Also effects of biochemical, physico-chemical and dynamic processes on their vertical distribution have been examined. Sulfate reduction in seawater and bottom sediments has been studied. Quantitative estimates of H2S fluxes at the water - bottom sediment and O2-H2S interfaces have been done. Features of H2S oxidation have been studied, its budget in the Black Sea has been calculated. Multiyear spatial-temporal variability of the oxic-anoxic interface has been investigated.