6,130 research outputs found
Development of an impact assessment framework for lean manufacturing within SMEs
No full textThe main aim of the research work presented in this thesis, is the development of a
novel framework with the capability of assessing the impact of implementing lean
manufacturing within small-to-medium sized manufacturing firms (SMEs). By assessing
the impact of lean implementation, SMEs can make informed decisions on the viability
of lean adoption at the conceptual implementation stage. Companies are also able
determine their status in terms of lean manufacturing affordability.
Thus, in order to achieve the above-stated aim, the following were the main set research
objectives; (1) identifying the key drivers for implementing lean manufacturing within
SMEs, (2) investigating the operational activities of SMEs in order to understand their
manufacturing issues, (3) exploring the current level of lean manufacturing usage within
SMEs so as to categorise users based on their levels of involvement, (4) identifying
factors that determine the assessment of lean manufacturing, (5) developing an impact
assessment framework for justifying lean manufacturing within SMEs, (6) developing a
knowledge based advisory system and (7) validating the impact assessment framework
and the developed knowledge based advisory system through real-life case studies,
workshops, and expert opinions.
A combination of research methodology approaches have been employed in this
research study. This comprises literature review, observation of companies' practices
and personal interview. The data collection process involved ten SMEs that provided
consistent information throughout the research project life. Additionally, visitations to
three large size manufacturing firms were also conducted. Hence, the framework and
system development process passed through several stages. Firstly, the data were
collected from companies who had successfully implemented lean manufacturing within
their premise. The second development stage included the analysis and validation of the
dataset through company practitioners. An impact assessment framework was thus developed with the aid of regression analysis as a predictive model. However, it was
realised that there were few correlations between the dataset generated and analysis. The
reasons for this were unclear.
,a
knowledge based advisory system was adopted to
conceptualise, enhance the robustness of the impact assessment framework and address
the problem of the imprecise data in the impact assessment process.
Three major factors of impact assessment were considered in the framework and the
system development process, namely relative cost of lean implementation, a company
lean readiness status and the level of value-added to be achieved (impact/benefits).
Three knowledge based advisory sub-systems that consisted of the abovementioned
factors were built. Results obtained from them were then fed into the final system. The
three sub-systems were validated with the original set of data from companies. This
enabled the assignment of a number of input variables whose membership functions
aided the definition of the fuzzy expert system language (linguistic variables) used. The
final system yielded heuristic rules that enable the postulation of scenarios of lean
implementation. Results were sought and tested on a number of firms based within the
UK, for the purposes validation. These also included expert opinions both in academic
and industrial settings.
A major contribution of the developed system is its ability to aid decision-making
processes for lean implementation at the early implementation stage. The visualisation
facility of the developed system is also useful in enabling potential lean users to make
forecasts on the relative cost of lean projects upfront, anticipate lean benefits, and realise
one' degree of lean readiness
Effect of the Elevated Temperature on Fatigue Behavior of Aluminum Alloy AA 7075
No full textيوضح هذا البحث تأثير عمر الكلال لسبيكة الألومنيوم (AA 7075)، وبظروف التحميل المستمر ذات القمة الثابته، مع زيادة درجة الحرارة. إن التنبؤ لعمر الكلال لعينات الالمنيوم المتعرضه للاحمال الديناميكيه باستخدام الطرق التجريبية التقليدية يجعل تحليل سلوك الكلال حقيقيًا ويعطي نتائج دقيقة. كذلك تم تمثيل منحنيات الإجهاد-عدد دورات الفشل للعينات عند درجات حرارة مختلفة (25، 75، 125، 175 و225 درجة مئوية). تمت مناقشة نتائج عمر الكلال عند درجة الحرارة الغرفه وعند درجات الحرارة المرتفعة من خلال علاقة باسكوين، وتم الحصول على انخفاض في عدد دورات الفشل للعينات المستخدمه عند زيادة درجة حرارة الاختبار. كذلك حصلت هذه الدراسه على توافق جيد عند مقارنة نتائج الدراسة الحالية مع نتائج تجريبية مستحصله من دراسات أخرى. كما أشتق نموذج عام (تعبير رياضي) لحساب عمر الكلال لسبيكة الألومنيوم (AA 7075) عند درجات حرارة مختلفة. يمكن استخدام هذا النموذج الرياضي المقترح الذي تم الحصول عليه في هذه الدراسة لتقليل تكلفة ووقت الطرق التجريبية لمعرفة سلوك الكلال لسبيكة الالمنيوم. كما انه وجد زيادة في معامل تقليل عمر الكلال (FLRF) مع زيادة في درجة حرارة الاختبار وكانت اعلى زيادة لاتتجاوز (43.963 ٪) وذلك في درجة حرارة 225 درجة مئوية نسبه الى درجة حرارة الغرفة عندما كانت قيمة الاجهاد المسلط تعادل (540 ميجا باسكال).This research presents the effect of fatigue life behavior of aluminum alloy AA 7075 under constant loading amplitude conditions and tested at different temperatures. The prediction of fatigue life using conventional experimental procedures makes the analysis of behavior is real and gives accurate results. The stress-life curves at different temperatures (25, 75, 125, 175 and 225 oC) were estimated. The results for fatigue life at ambient temperature and at elevated temperatures were discussed by the Basquin\u27s relation, and a decrease in fatigue life cycles was found when increasing the testing temperature. Good agreement has been obtained when comparing the current study results with other available experimental data by other studies. A general proposed model (mathematical expression) was formulated to calculate the fatigue life for aluminum alloy AA 7075 at different temperatures. The proposed mathematical model obtained in this study can be used for decreasing the cost and time of the experimental procedures. Also, the Fatigue Life Reduction Factor (FLRF) was increased with increased of the testing temperature at maximum value of (43.963%) occurred at temperature of 225 °C compared with room temperature when applied stress be equal to 540 MPa
COMMERCIAL 584\AA PHOTOELECTRON SPECTROMETER
No full textAuthor Institution: Perkin-Elmer LimitedThe design of a commercial 584\AA Photcelectron Spectrometer will be discussed together with some recent research problems investigated by this technique
Open Access to Peer-Reviewed Research through Author/Institution Self-Archiving: Maximizing Research Impact by Maximizing Online Access
No full textAll refereed journals will soon be available online; most of them already are. This means that anyone will be able to access them from any networked desk-top. The literature will all be interconnected by citation, author, and keyword/subject links, allowing for unheard-of power and ease of access and navigability. Successive drafts of pre-refereeing preprints will be linked to the official refereed draft, as well as to any subsequent corrections, revisions, updates, comments, responses, and underlying empirical databases, all enhancing the self-correctiveness, interactivity and productivity of scholarly and scientific research and communication in remarkable new ways. New scientometric indicators of digital impact are also emerging <http://opcit.eprints.org> to chart the online course of knowledge. But there is still one last frontier to cross before science reaches the optimal and the inevitable: Just as there is no longer any need for research or researchers to be constrained by the access-blocking restrictions of paper distribution, there is no longer any need to be constrained by the impact-blocking financial fire-walls of Subscription/Site-License/Pay-Per-View (S/L/P) tolls for this give-away literature. Its author/researchers have always donated their research reports for free (and its referee/researchers have refereed for free), with the sole goal of maximizing their impact on subsequent research (by accessing the eyes and minds of fellow-researchers, present and future) and hence on society. Generic (OAi-compliant) software is now available free so that institutions can immediately create Eprint Archives in which their authors can self-archive all their refereed papers for free for all forever <http://www.eprints.org/>. These interoperable Open Archives <http://www.openarchives.org> will then be harvested into global, jointly searchable "virtual archives" (e.g., <http://arc.cs.odu.edu/>). "Scholarly Skywriting" in this PostGutenberg Galaxy will be dramatically (and measurably) more interactive and productive, spawning its own new digital metrics of productivity and impact, allowing for an online "embryology of knowledge.
Author attribution using profile classifiers
No full textA atribuição autoral (AA) busca identificar um autor de texto a partir de um conjunto de autores conhecidos. Autores deixam rastros em seus textos e é possível identificar características sociolinguísticas baseadas no estilos de escrita refletidos no texto destes autores. A atribuição autoral está cada vez mais demonstrando importância para diversas atividades sociais, em especial para a análise forense. Os trabalhos envolvendo AA demonstram resultados modestos e motivam a exploração de diferentes técnicas para melhorar a acurácia dos modelos atuais. A partir desses pontos, o presente trabalho apresenta uma proposta de pesquisa em nível de mestrado no campo de processamento de língua natural (PLN), com ênfase em AA, com o objetivo geral de melhorar o desempenho de classificadores de atribuição autoral utilizando técnicas de caracterização autoral (CA)Author attribution (AA) seeks to identify a text author from a set of known authors. Authors leave traces in their texts and it is possible to identify sociolinguistic characteristics based on the writing styles reflected in the text of these authors. Author attribution is increasingly showing importance for various social activities, especially forensic analysis. Studies involving AA show modest results and motivate the exploration of different techniques to improve the accuracy of current models. From these perspective, this project presents a master\'s level research proposal in the field of natural language processing (NLP), with an emphasis in AA, with the general objective of improving the performance of AA classifiers using author profiling technique
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Observations of the 57Fe+23 hyperfine transition in clusters of galaxies
No full textWe present a search for the hyperfine transition of the 57Fe+23 ion at 3.071 mm in clusters of galaxies with the ATNF Mopra telescope. The results are compared with a realistic estimate of the peak brightness temperature of the line in a cooling flow cluster A85, using the available X-ray data
THE ANALYSIS OF FIVE ELECTRONIC EMISSION SYSTEMS OF NIOBIUM NITRIDE (NbN) IN THE REGION 5000{\AA} – 6200{\AA}
No full textK. H. Rao and T. M. Dunn, Nature 222, 266 (1969). J. L. Femenias, C. Athenour, and T. M. Dunn, J. Chem. Phys. 63, 2861 (1975).Author Institution:Niobium nitride emission systems have been found at 5l37{\AA}, 5582{\AA}, 5740{\AA}, 5840{\AA}, 5860{\AA}, in addition to the already systems with subbands at 5930{\AA}, 6043{\AA}, and 6192{\AA}. Most of These systems show marked nuclear hyperfine structure of the rotational lines add this has been of assistance in the analysis of all of the systems. Systems of triplet-triplet, singlet-singlet and singlet-triplet are all present and the hyperfine structure also allows assignment of the ground and excited state electron configuration to be made with some confidence
THE 4550 {\AA} BAND SYSTEM OF GLYOXAL
No full textAuthor Institution: Division of Pure Physics, National Research Council“Approximately 45 bands of glyoxal in the region 4000-4660 {\AA} have been photographed in absorption using a 30 ft. Ebert spectrograph with a resolving power of and a dispersion of 1.3 {\AA}/cm. The (0-0) baud near 4550 {\AA}, which WAS studied at a temperature of C, shows fairly well-resolved J- and K- structure characteristic of a perpendicular hand of a near symmetric top molecule. The rotational and vibrational analysis of the speetrum will be discussed.
THE ABSORPTION SPECTRUM OF SODIUM VAPOR FROM 1040{\AA} TO 3500 {\AA}
No full textR. W. Ditchburn and R. D. Hudson, Proc, Roy. SOC. A256, 53 (1960). R. W. Ditchburn, P. J. Jutsum and G. V. Marr, Proc. Roy. Soc. A219, 89 (1953).Author Institution: Space Physics Laboratory, Aerospace Corporation“The absorption of ultraviolet radiation by sodium vapor, and the associated ionization, has been investigated from 1040{\AA} to 3500{\AA} using a two-metre McPherson normal incidence spectrometer and an absorption chamfer of the type described by Ditchburn and The atomic cross section at the series limit (2412 {\AA}) was found to be , in good agreement with the previous result obtained by Ditchburn, Jutsum and The atomic cross section decreases to a minimum at 1900{\AA} and then increases again towards shorter wavelengths. Continuous molecular absorption was observed from 3500{\AA} to 1700{\AA} and ion chamber measurement indicate that this absorption is due to an ionization continuum. Ion current peaks were also seen between 2413{\AA} and 3500{\AA} at wavelengths corresponding to the series absorption lines of the sodium atom. Curves will be presented showing the variation with wavelength of both the atomic cross section and the relative molecular cross section.
ROTATIONAL ANALYSIS OF THE 6125 {\AA} REGION OF NITROGEN DIOXIDE
No full textAuthor Institution: Department of Chemistry, Columbia University; Laboratoire de Photophysique, Moleculaire C.N.R.S. University of Paris-Sud; Department of Chemistry, Columbia UniversityFrom an analysts of the rotationally resolved fluorescence of excited by a narrow band (0.03 {\AA}) tunable dye laser, quantum numbers have been assigned to 80 transitions in the 6l25 {\AA} region. Three band origins are observed in a 20 {\AA} interval, two of which have also been seen in a nozzle beam seeded with A rotational analysis of the 6125 {\AA} and 6127 {\AA} bands is reported, while the small number of transitions assigned to the 6117 {\AA} band presently prevents analysis. Under collision-free conditions ( mTorr) the ``average” radiative lifetimes of the 6117 {\AA} band and the 6125 {\AA} band are sec and sec, respectively. Comments are made concerning the vibrational overlap in this region
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