358 research outputs found

    Development of genetic algorithm based classification and cluster analysis methods for analytical data

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    Thesis (Doctoral)--İzmir Institute of Technology, Chemistry, İzmir, 2009Includes bibliographical references (leaves: 151-158)Text in English; Abstract: Turkish and Englishxviii, 158 leavesIn this study genetic algorithm based classification and clustering methods were aimed to develop for the spectral data. The developed methods were completely achieved hybridization of nature inspired algorithm (genetic algorithms, GAs) to other classification or clustering methods. The first method was genetic algorithm based principal component analysis (GAPCAD), and the second was genetic algorithm based discriminant analysis (GADA). Both methods were performed to achieve the best discrimination between the olive oil and vegetable oil samples. The classifications of samples were examined directly from their spectral data obtained from using near infrared spectrometry, Fourier transform infrared (FTIR) spectrometry, and spectrofluorometry. The GA was used to optimize the performance of classification or clustering techniques. on training set in order to maximize the correct classification of acceptable and unacceptable samples or samples of dissimilar properties and to reduce the spectral data by wavelength selection. After GA optimization the classification results of training set were controlled by validation set. Lastly, the success of both algorithms was compared to the results of PCA and SIMCA

    Monitoring the esterification reactions of carboxylic acids with alcohols using near-infrared spectrocopy and multivariate calibration methods

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    Thesis (Master)--İzmir Institute of Technology, Chemistry, İzmir, 2003Includes bibliographical references (leaves: 81-84)Text in English; Abstract: Turkish and Englishix, 84 leavesSimultaneous determination of mixtures of alcohols, acids, esters, and water using near-infrared spectroscopy (NIR) and four different multivariate calibration methods were realized. The four multivariate calibration methods were Genetic Inverse Least Squares (GILS), Genetic Regression (GR), Principle Component Regression (PCR), and Partial Least Squares (PLS). Four different esterification reactions were investigated. These are methyl acetate, ethyl acetate, propyl acetate, and butyl acetate.The sample set contains 40 ternary mixtures of these esterification processes. Duplicate measurements were done for each sample and 80 NIR absorbance spectra that cover the range from 4000 to 10000 cm.1 were obtained. Of these 80 spectra, 50 were used as calibration set, 30 were reserved for the prediction purposes. Several calibration methods were built for each component of each esterification reactions. Standard error of calibration (SEC) and standard error of prediction (SEP) were calculated for each calibration model and comparison of these four multivariate calibration methods was done

    Fatores Ambientais que Influenciam a Criatividade Culinária sob a Perspectiva de Profissionais da Cozinha Turca

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    This study explores environmental factors that influence the culinary creativity of Turkish cuisine. Although Turkish food culture is known for its richness and diversity in terms of ingredients and cooking techniques, the assumption is that environmental factors cause some recognition and representation issues internationally. For this reason, a quantitative questionnaire study was carried and aimed to understand perceptions of chefs (hotel and restaurant chefs) and academicians (instructor chefs and academicians) towards factors that influence culinary creativity in Turkey. The exploratory factor analysis revealed six environmental factors that impact the culinary creativity of Turkish cuisine. These are (1) politics and economics, (2) education, (3) culture, (4) media and globalization, (5) technology, science, and design, (6) tourism. According to the study results, while the highest scores were given to educational factors by the participants, the media and globalization's impact was found to be the least concerned factors. The results demonstrate the significant differences are between participants' job specifications, genders, and education degrees. Moreover, this study suggests that cuisine is a designed phenomenon since it includes unique ingredients, cooking techniques and skills, flavors principles, and particular stakeholders. Thus, the proper management of these elements will provide cuisine a competitive advantage in the culinary industry. Chefs are the primary actors representing a cuisine in the international culinary industry and differentiate it from its competitors with their creative approaches.Este estudio explora los factores ambientales que influyen en la creatividad culinaria de la cocina turca. Aunque la cultura gastronómica turca es conocida por su riqueza y diversidad en cuanto a ingredientes y técnicas culinarias, se supone que los factores ambientales causan algunos problemas de reconocimiento y representación a nivel internacional. Por esta razón, se llevó a cabo un estudio cuantitativo mediante un cuestionario con el objetivo de conocer las percepciones de los chefs (cocineros de hoteles y restaurantes) y de los académicos (cocineros instructores y académicos) sobre los factores que influyen en la creatividad culinaria en Turquía. El análisis factorial exploratorio reveló seis factores ambientales que influyen en la creatividad culinaria de la cocina turca. Se trata de (1) la política y la economía, (2) la educación, (3) la cultura, (4) los medios de comunicación y la globalización, (5) la tecnología, la ciencia y el diseño, (6) el turismo. Según los resultados del estudio, mientras que las puntuaciones más altas fueron otorgadas a los factores educativos por los participantes, el impacto de los medios de comunicación y la globalización resultaron ser los factores menos preocupantes. Los resultados demuestran que hay diferencias significativas entre las especificaciones de los puestos de trabajo, los géneros y los grados de educación de los participantes. Además, este estudio sugiere que la cocina es un fenómeno diseñado ya que incluye ingredientes únicos, técnicas y habilidades culinarias, principios de sabores y actores particulares. Así, la gestión adecuada de estos elementos proporcionará a la cocina una ventaja competitiva en la industria culinaria. Los chefs son los principales actores que representan a una cocina en la industria culinaria internacional y la diferencian de sus competidores con sus enfoques creativos.Este estudo explora os fatores ambientais que influenciam a criatividade culinária da culinária turca. Embora a cultura alimentar turca seja conhecida por sua riqueza e diversidade em termos de ingredientes e técnicas de cozimento, o pressuposto é que fatores ambientais causam alguns problemas de reconhecimento e representação internacional. Por esse motivo, foi realizado um estudo de questionário quantitativo com o objetivo de compreender as percepções de chefs (chefs de hotéis e restaurantes) e acadêmicos (chefs instrutores e acadêmicos) sobre os fatores que influenciam a criatividade culinária na Turquia. A análise fatorial exploratória revelou seis fatores ambientais que impactam a criatividade culinária da cozinha Turca. São eles (1) política e economia, (2) educação, (3) cultura, (4) mídia e globalização, (5) tecnologia, ciência e design, (6) turismo. De acordo com os resultados do estudo, enquanto as pontuações mais altas foram atribuídas aos fatores educacionais pelos participantes, a mídia e o impacto da globalização foram considerados os fatores menos preocupados. Os resultados demonstram que as diferenças significativas estão entre as especificações de trabalho dos participantes, gêneros e graus de escolaridade. Além disso, este estudo sugere que a culinária é um fenômeno projetado, pois inclui ingredientes únicos, técnicas e habilidades culinárias, princípios de sabores e partes interessadas específicas. Assim, a gestão adequada destes elementos proporcionará à gastronomia um diferencial competitivo no setor culinário. Os chefs são os principais atores que representam uma culinária na indústria culinária internacional e a diferenciam de seus concorrentes com suas abordagens criativas

    On eqiform Darboux helices in Galilean 3-space

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    In this paper, we define equiform Darboux helices in a Galilean space (G_{3}) and obtain their explicit parameter equations. We show that equiform Darboux helices have only a non-isotropic axis and characterize equiform Darboux vectors of equiform Darboux helices in terms of equiform rectifying curves. We prove that an equiform Darboux vector of an equiform Darboux helix α is an equiform Darboux helix if an admissible curve (alpha) is a rectifying curve. We also prove that there are no equiform curves of constant precession and give some examples of equiform Darboux helices

    On translation surfaces in 4-dimensional Euclidean space

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    We consider translation surfaces in Euclidean spaces. Firstly, we give some results of translation surfaces in the 3-dimensional Euclidean space E3. Further, we consider translation surfaces in the 4-dimensional Euclidean space E4. We prove that a translation surface is flat in E4 if and only if it is either a hyperplane or a hypercylinder. Finally we give necessary and sufficient condition for a quadratic triangular Bézier surface in E4 to become a translation surface

    Geophysikalische Erfassung von Feuchte- und Substratheterogenitäten im Boden auf unterschiedlichen Skalen

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    Soils interact with the hydro-, bio- and atmosphere and fulfil different environmental functions. Sufficient analysis of current and historical processes in soils is necessary to optimise soil conservation and to minimize damage to the ecosystem. Modelling of transport processes in soils provides knowledge of the complex environmental interaction. This requires extensive data with an appropriate resolution. The general aim of this thesis was to use geophysical methods for determining spatial and temporal heterogeneity of water and substrate. DC-geoelectrics and GPR provide three-dimensional images of near surface structures based on changes in electromagnetic and electrical conductivity. It is shown that geophysical methods enable spatial mapping of soil properties on different scales and that these methods can be used at different scales. This is important for a variety of reasons in disciplines such as soil sciences, hydrology and agronomy

    k-type null slant helices in Minkowski space-time

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    In this paper, we introduce a notion of a kk-type null slant helices inMinkowski space-time, where kin0,1,2,3kin {0,1,2,3}. We give the necessary andsufficient conditions for null Cartan curves to be kk-type null slanthelices in terms of their curvatures kappa2kappa _{2} and kappa3kappa _{3}. Inparticular, we characterize kk-type null slant helices lying inpseudosphere S13(r)S^{3}_{1}(r). We find the relationships between 00-type and %1-type null slant helices, as well as between 11-type and 22-type nullslant helices. Moreover, we prove that there are no 33-type null slanthelices in Minkowski space-time

    Examination of factors that prevent participation of trainers working in public education centers in recreational activities (Kocaeli City case)

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    Bu araştırmada, Kocaeli Halk Eğitim Merkezi’nde eğitmen olarak çalışmakta olan bireylerin rekreatif etkinliklere katılımlarına engel olan faktörlerin incelenmesi amaçlanmıştır. Çalışmada betimsel tarama modelinden ilişkisel tarama modeli kullanılmıştır. Araştırmaya, Kocaeli Halk Eğitim Merkezi’nde hem sözleşmeli hem de kadrolu olarak çalışmakta olan 147’si kadın 57’si erkek olmak üzere toplam 204 eğitmen gönüllü olarak katılım sağlamıştır. Alexandris ve Carroll (1997) tarafından geliştirilen, Türkçe uyarlaması, geçerlik ve güvenirlik çalışması Karaküçük ve Gürbüz (2006) tarafından yapılan “Boş Zaman Engelleri” ölçeği kullanılmıştır. Ölçek, toplam 6 alt boyut ve 27 maddeden oluşmaktadır. Araştırmada kullanılan boş zaman engelleri ölçeğinden elde edilen verilerin frekans ve yüzde değerleri alındıktan sonra parametrik testlerden bağımsız örneklem t-testi ve ANOVA testi uygulanmıştır. Anlam düzeyi 0.05 olarak alınmıştır. Elde edilen bulgulara göre, halk eğitim merkezinde çalışan eğitmenlerin rekreatif etkinliklere katılımını etkileyen faktörlerde ölçeğin alt boyutları incelendiğinde ortalamalarının orta düzeye yakın, ancak yüksek olduğu ve boş zaman engellerine maruz kalındığı görülmektedir. Ölçekten elde edilen puan ortalamalarının en yüksek ortalaması tesis yetersizliği boyutunda görülürken en düşük ortalama arkadaş eksikliği boyutunda görülmüştür.In this research is the examine the factors that prevent the participation of trainers working in Kocaeli Public Education Centers in recreational activities. The study group a total of 204 trainers,147 of whom are women and 57 of whom are men working both contracted and staffed voluntarily participated in this research.''Leisure Time Barriers'' scale,which was developed by Alexandris and Carroll(1997)and adapted to Turkish and validity and reliability study was performed by Gurbuz and Karakuçuk (2006),was used in this research. The scale consists of 6 sub-dimensions and 27 substances.After the frequency and percentage values of the data obtained from the leisure time barriers used in the research, Independent sample t-test and ANOVA test from parametric tests were applied.The significance level was taken as 0.05.According to the results, when the sub-dimensions of the scale were examined in the factors affecting the participation of trainers working in public education center in recreational activities,it is seen that their averages are close to medium level but they are high, and they are exposed to leisure time barriers. The highest average of the mean scores obtained from the scale was found to be because of the shortage of facilities and the lowest average was found to be the lack of friends

    Antimicrobial activity and in vivo toxicity evaluation of Foeniculum vulgare Mill. essential oil

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    Foeniculum vulgare Mill. (Apiaceae) is commonly known as “fennel”, a small genus of annual, biennial or perennial herbs distributed in central Europe and the Mediterranean region. It is widely cultivated throughout the temperate and tropical regions of the world for its aromatic fruits, which are used mainly as a culinary spice [1]. Fruits and essential oil of F. vulgare are used as flavoring agents in food products, in cosmetic and pharmaceutical products. The essential oil is accredited with antioxidant, antimicrobial, antithrombotic, antidiabetic activities, among others [2].                In this present work, it was aimed to determine the antimicrobial activity of the pharma grade F. vulgare essential oil. trans-Anethole (68.2%), fenchone (12.8%) and limonene (6.5%) were confirmed as the main constituents; the analysis was performed by GC/FID and GC/MS, simultaneously. Antimicrobial activity of the essential oil was tested against Escherichia coli NRRL B-3008, Bacillus cereus NRRL B3711, Salmonella typhimurium ATCC 13311 and Streptococcus sanguinis ATCC 10556 by a broth microdilution assay [3]. Minimum Inhibitory Concentrations (MIC) were found to be: 6.25, 6.25, 3.12 and 12.5 mg/mL, respectively, suggesting that the antimicrobial activity of the essential oil was relatively low against the tested pathogens. In addition, lethal concentration (acute toxicity) was determined using the in vivo animal alternative Caenorhabditis elegans test [4]. Lethal concentration (LC50, 50% of killed nematodes) for the essential oil was determined to be <25 mg/mL
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