• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 216
  • 189
  • 26
  • 20
  • 18
  • 14
  • 13
  • 10
  • 4
  • 4
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 588
  • 134
  • 115
  • 87
  • 80
  • 66
  • 62
  • 61
  • 45
  • 44
  • 43
  • 40
  • 37
  • 36
  • 34
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Avaliação da qualidade do leite e de queijos produzidos pela agricultura familiar, em sistemas de produção ecológico e convencional, no leste do Rio Grande do Sul

Fernandez, Victoria Noel Vázquez January 2010 (has links)
A produção leiteira do Brasil vem crescendo anualmente desde a década de 1990. Em todo o país a agricultura familiar tem grande participação na produção de leite, sendo que no Rio Grande do Sul mais de 80% do volume de leite entregue à industria é oriundo de propriedades familiares, Essas propriedades adotam sistemas de produção diferenciados quanto à adoção de insumos, podendo ser convencionais ou ecológicas, e muitas vezes procura agregar valor à produção através do beneficiamento do leite a derivados lácteos. O presente trabalho teve como objetivo avaliar a qualidade do leite, produzido em sistema convencional e ecológico, e de queijos artesanais oriundos da agricultura familiar e verificar se a qualidade destes está adequada às respectivas legislações vigentes. O trabalho foi realizado entre outubro de 2008 e setembro de 2009, quando 10 UPL da agricultura familiar localizadas na região leste do Rio Grande do Sul eram visitadas mensalmente. Nessa ocasião foram coletadas amostras compostas de leite (do tanque de resfriamento) de cada uma das propriedades e encaminhadas à análise da composição química, contagem de células somáticas, contagem bacteriana total e análises físico-quimicas. Nos meses de fevereiro e julho de 2009 foram coletadas amostras dos alimentos ofertados aos animais em cada uma das propriedades, estes foram submetidos à análise bromatológica para determinação de PB, FDN e FDA, em junho de 2009 foram amostradas a agua utilizada durante a ordenha dos animais e queijos produzidos artesanalmente por essas familias. O leite da agricultura familiar apresentou CCS e CBT medias em valores acima do estabelecido na Instrução Normativa nº51, enquanto que o teor de lactose foi inferior ao esperado. Não houve diferença significativa entre os parâmetros de qualidade do leite avaliados para os diferentes sistemas, contudo a CBT apresentou interação significativa quanto ao sistema x mês. As contagens bacterianas foram maiores nos meses de primavera e verão, bem como a produção de leite. Os queijos produzidos pelas agroindustrias avaliadas e que foram produzidos a partir de leite cru apresentaram qualidade microbiológica inadequada aos padrões estabelecidos pela Resolução RDC nº12, tendo sido considerados inadequados ao consumo humano. A estrutura para a produção de queijos utilizada pelos agricultores familiares apresenta deficiências e inadequações em todas as propriedades estudadas. Na situação avaliada não houve diferença significativa entre a qualidade do leite produzido nos diferentes sistemas, ecológico e convencional, ainda assim a agricultura familiar apresentou problemas relacionados ao manejo nutricional e higiênico que podem prejudicar a qualidade do leite, tendo sido mais preocupantes os dados referentes à CCS, CBT e ESD. Quanto aos queijos e procedimentos de fabricação utilizados nas propriedades avaliadas, ficou evidente que as deficiências no tratamento térmico adequado do leite usado na produção de queijos de muito alta umidade afetam diretamente a qualidade microbiológica desses produtos, colocando em risco a saúde do consumidor. A implementação de ações de Boas Práticas de Fabricação seria importante para auxiliar o controle de contaminações e possíveis toxinfecções. / The dairy production of Brazil has been growing up yearly since the 1990 decade. In the whole country family agriculture has a high engagement in milk production, while in the State of Rio Grande do Sul, more than 80% of the milk delivered to the industry is originated in family properties. These properties adopt differentiated production systems in relation to the use of raw materials, as they could be conventional or ecological, and many times they try to add value through the manufacturing of milk to dairy products. This piece of work had the objective of evaluating the quality of milk produced through the conventional system (CONV) and ecological (ECO), and of homemade cheeses originated from family agriculture and to verify if the quality of these products is in accordance with the respective current regulations. The work was performed between October 2008 and September 2009, when 10 family agricultural UPL‟s (Dairy Production Units), located in the eastern region of Rio Grande do Sul were visited monthly. During these visits milk samples from the herds and cooling tanks from each one of the properties were collected and sent for chemical and physical analysis, counting of somatic cells and total bacterial count. During the months of February and July 2009 samples of the feed offered to the animals in each one of the properties were collected. These samples were subject of bromatology analysis to determine PB (Gross Protein), FDN (Neutral Detergent Fiber), and FDA (Acid Detergent Fiber). In June 2009 samples were taken from: water used during milking and homemade cheeses produced by these families. The milk from agricultural family presented average CCS (Somatic Cells Count) and CBT (Total Bacterial Count) above the values established by Regulatory Instruction Nº 51, while the lactose percentage was lower than expected. There was no significant difference between the evaluated milk quality parameters for the different systems, though the CBT presented a significant interaction in relation to the system/month, whereas a significant monthly variation was verified in the ECO. The bacterial counts were higher during the spring and summer months. During this period higher milk production was observed. Cheeses produced by the evaluated agroindustrial units and that were produced from raw milk presented inadequate microbiological quality according to standards established through Resolution RDC nº 12, thus considered inadequate for human consumption. The structure used by family agricultural labourers for cheese production presents deficiencies and inadequacies in all the properties studied during this work. In the evaluated situation there was no significant difference between the quality of milk produced through the different systems, ecological and conventional. The family agriculture presented problems related to the nutrition and hygienical handling that can impair milk quality, while the data in reference to CCS, CBT and ESD is more worrisome. In relation to the cheese and manufacturing practices used in the evaluated properties, it was clear and evident that the deficiencies in the thermal treatment of milk used in the production of high humidity cheeses influences directly the microbiological quality of these products, leaving the consumer‟s health under risk. The implementation of Good Manufacturing Practices would be important to help the control of contamination and possible intoxications.
92

Avaliação da implantação das boas práticas agropecuárias para a qualidade e segurança do leite de uma cooperativa do Estado do Rio Grande do Sul

Martello, Leonir January 2017 (has links)
A cadeia do leite tem um importante papel na ordem econômica e social do agronegócio brasileiro. A qualidade do leite produzido no Brasil ainda está abaixo do tecnicamente recomendável, fazendo com que fique comprometida a inocuidade dos alimentos lácteos ofertados à população e também às possibilidades do Brasil de se estabelecer como um forte competidor no mercado internacional. A melhoria da qualidade sanitária do leite está relacionada a adoção de Boas Práticas Agropecuárias (BPA), visando prevenir possíveis falhas no processo de produção. O objetivo deste trabalho foi identificar as características das propriedades produtoras de leite associadas a uma Cooperativa do estado do RS, bem como avaliar a eficácia da implantação do Programa Alimentos Seguros (PAS Leite Campo), no âmbito dos critérios legais de conformidade na qualidade higiênico-sanitária do leite produzido. Para isto foi utilizada a metodologia de Implantação Orientada desenvolvida pelo PAS Campo – Leite, em 59 produtores. No início e no final da implantação foram identificados dados para caracterização das propriedades e avaliados os indicadores de percentagem de conformidade dos itens da lista de verificação das BPA, que foram divididos em localização e instalações; segurança da água; capacitação e saúde do trabalhador; manejo da ordenha; higiene de equipamentos e utensílios; refrigeração e estocagem; controle de pragas; manejo sanitário e armazenamento dos alimentos, bem como da qualidade higiênico-sanitária da matéria-prima (leite), através de análises de contagem de células somáticas (CCS) e contagem de bactérias totais (CBT), antes e no decorrer da implantação do programa Para analisar os dados foi utilizado o software “Statistical Package for the Social Sciences” (SPSS), através do teste de ANOVA, a fim de identificar a diferença estatística entre resultados com significância de 5% para análise das médias. Todas as propriedades estudadas possuíam ordenha mecânica e equipamento de refrigeração, uma produção média de 22,91 L/vaca /dia, em um plantel de 3.127 vacas, sendo 1.577 em lactação, totalizando a produção de 36.130 litros por dia. Os resultados de conformidade geral apresentaram uma evolução positiva de 64,41% inicialmente e alcançaram no final da implantação 96,20% do total. As contagens de CCS e CBT apresentaram quedas significativas no desenvolver do projeto. Com base no exposto, pode-se concluir que a adoção da BPA através do PAS foi eficaz para adequação das propriedades produtoras de leite aos critérios legais, bem como para a melhoria-higiênico sanitária do leite. / Milk food chain has an important role in the economic and social order of Brazilian agrobusiness. Sanitary quality of milk produced in Brazil still remains well below the technically recommended, compromising both the harmlessness of dairy products offered to population and Brazil’s possibilities to be established as a strong competitor in international market. Improvements in milk sanitary quality are linked with the adoption of Good Agricultural Practices (GAP), aiming to correct possible flaws in the production process. The objective of the present study was to identify the characteristics of milk producing proprieties associated with a state’s Cooperative from Rio Grande do Sul (RS), as well as evaluate the efficacy of the implantation of the Safe Food Program (SFP Milk - Field) in the scope of conformity legal criteria in the hygienic-sanitary quality of milk produced. For that, methodology of Oriented Implantation developed by the SFP Milk - Field was used, in 59 milk producers. At the start and ending of the implantation, data for the characterization of proprieties was identified, whereas indicators of the conformity percentage of items from the verification list of GAP were evaluated, the last being divided in localization and installations; water safety; health and capacity of workers; milking handling; hygiene of equipment and utensils; refrigeration and storage; plague control; sanitary handling and food storage, as well as hygienic-sanitary quality of raw material (milk), through the analyses of somatic cell count (SCC) and total bacterial count (TBC), before and during the program’s implantation For data tabulation, software “Statistical Package for the Social Sciences” (SPSS) was used together with ANOVA test, aiming to identify the statistical difference between results with significance of 5% for average analysis. All proprieties studied had mechanical milking and refrigeration equipment; average milk production was of 21.81 L/cow/day, in a herd of 3,127 cows, being 1,577 in lactation, totalizing a production of 36,130 Liters per day. General conformity results showed a positive evolution of 64.41%, reaching up to 96.20% at the end of implantation. SCC and TBC counting showed significant decreases with the development of the project. Based on the exposed, it is possible to conclude that the adoption of GAP through SFP is effective for the adequacy of milk producing proprieties to legal criteria, as well as to the improvement of milk hygienic and sanitary quality.
93

Hygienické parametry syrového kravského mléka ve vztahu k použité dezinfekci mléčné žlázy. / Hygienic parametres of raw cow´s milk in relation to used disinfection of mammary gland.

PEŠLOVÁ, Pavla January 2008 (has links)
The goal of the graduation theses was a comparison of the hygenic quality of raw cows milk, it was expressed by the value of total bacterial count (TBC) and somatic cells count (SCC) in four breeds of milking cows using only postdipping (3 breeds) in comparison with breed using predipping and postdipping. The breeds differed in technology of lairage and milking procedures, grazing and the size the herd. During two seasons 2006 till 2007 was discovered that the breeds using predipping and postdipping had significantly less average values of TBC (9,46.103.ml-1) in comparison with the breeds using only postdipping (15,97.103.ml-1), the difference was statistically significant (P = 0,007) on the level of significance P < 0,05. Also it was shown that SCC were below averages levels with using predipping and postdipping (293,47.103.ml-1) in comparison to breeds using only postdipping (312,06.103.ml-1), the difference was also statistically significant (P = 0,01) on the level of significance P < 0,05.
94

ANALÝZA VYBRANÝCH JAKOSTNÍCH UKAZATELŮ SYROVÉHO KRAVSKÉHO MLÉKA V ZEMĚDĚLSKÉM PODNIKU / ANALYSIS OF SELECTED INDICATORS OF QUALITY OF RAW COW'S MILK IN AGRICULTURAL ENTERPRISE

HUBENÁ, Šárka January 2011 (has links)
The aim of my thesis was to analyze the quality parameters of raw bulk milk with a focus on hygienic and microbiological quality. For this purpose we choose two markers: somatic cell count (SCC) and total bacterial count (TBC). Data were obtained from two dairy farms Dolní Bukovsko and Popovice for the period from June 2008 to February 2011. For statistical evaluation was used MS Excel and Statistics 6.0. SCC and the average TBC values were recorded at higher density in Dolní Bukovsko. However, the averages for these two breeds are consistent with the legislation of the European Union and the Czech Republic (both TBC (?100,000/ml) and SCC (?400,000/ml)). Even though the average TBC value exceeded the limit of the breeding herd health PSB ? 200 thousand / ml, indicating the possible presence of subclinical mastitis and bonded with the considerable economic losses in milk production.
95

Qualidade do leite cru e práticas de manejo em fazendas leiteiras / Quality of raw milk and management practices in dairy farms

Cristina Simões Cortinhas 18 December 2013 (has links)
O objetivo geral do estudo foi avaliar os fatores de risco associados com práticas de manejo e a qualidade higiênica do leite cru, e caracterizar o nível de conhecimento e opiniões de produtores de leite sobre controle de mastite e qualidade do leite. Os objetivos específicos foram avaliar os fatores de risco associados com a qualidade higiênica do leite, determinar o efeito do tipo de agente causador de mastite sobre a qualidade do leite cru, e avaliar a associação entre o nível de conhecimento dos produtores e a contagem de células somáticas (CCS) do leite de tanque. O presente estudo foi dividido em três experimentos. No experimento 1, para avaliação de práticas de manejo associadas à qualidade higiênica do leite cru em rebanhos leiteiros, foram selecionados 120 rebanhos de acordo com a média geométrica da contagem bacteriana total (CBT) de 10 amostras de leite/ rebanho coletadas durante dois meses consecutivos, para compor dois grupos: 60 com alta CBT (1,11x104 UFC/mL) e 60 com baixa CBT (4,4x103 UFC/mL). Após a seleção, amostras de leite foram coletadas uma vez por semana durante dois meses para determinação da CBT, contagem do leite com incubação preliminar (CIP), contagem do leite pasteurizado (CLP), contagem de coliformes (CC), CCS e de concentrações de gordura, proteína e sólidos totais. Após a realização das análises, 63 rebanhos foram selecionados e visitados para aplicação de questionário sobre: a) informações gerais de manejo do rebanho; b) manejo de ordenha; c) procedimentos de limpeza de equipamento de ordenha e utensílios; d) programa de controle da mastite; e) condições de limpeza do úbere. Para o experimento 2, o nível de conhecimento e as opiniões dos produtores de leite sobre mastite e qualidade do leite, foram avaliados em 63 rebanhos selecionados e distribuídos de acordo com as médias geométricas da CCS (8 coletas semanais consecutivas durante dois meses) em três grupos: a) baixa CCS: &#8804; 250.000 céls/mL(n = 16); b) média CCS: >250.000 &#8804; 400.000 céls/mL (n = 24); c) alta CCS: > 400.000 céls/mL(n = 23). Nos rebanhos selecionados, foram aplicados questionários aos responsáveis pelo manejo do rebanho, com questões sobre: características socioeconômicas, conhecimentos a respeito de CCS, CBT e mastite e comportamentos dos produtores com relação a práticas de prevenção da mastite. No experimento 3, para avaliação da associação entre patógenos causadores de mastite e qualidade do leite, foram selecionados 90 rebanhos com base na CCS do tanque de 10 amostras/ rebanho coletadas durante dois meses consecutivos, para compor os seguintes grupos: a) &#8804; 250.000 céls/mL (n = 30); b) >250.000 &#8804; 600.000 céls/mL (n = 30); c) >600.000 céls/mL (n = 30). As amostras do leite de tanque foram coletadas, a cada 15 dias por um período de 3 meses, para determinação da contagem de Staphylococcus aureus, contagem de Streptococcus agalactiae, contagem de estafilococos coagulase-negativa, contagem de estreptococos ambientais, contagem de Escherichia coli, contagem de coliformes totais, CBT, CCS e de concentrações de gordura, proteína e sólidos totais. A alta quantidade de matéria orgânica presente na válvula de saída do tanque de expansão é um fator de risco para a qualidade higiênica do leite cru; o uso do desinfetante de tetos pré e pós-ordenha são práticas de manejo que reduzem a contagem dos principais indicadores de qualidade higiênica do leite e a prática de ordenha com o bezerro ao pé da vaca está associada ao aumento de CBT, CIP e CC. Outros fatores socioeconômicos como ter o leite como principal atividade econômica na propriedade, o tipo de ordenha utilizada no rebanho, o uso de métodos para detecção de mastite e o conhecimento das exigências legais de CCS e CBT foram fatores associados à CCS do leite de tanque. Adicionalmente, altas contagens de Streptococcus agalactiae reduzem a qualidade do leite de tanque por estarem correlacionadas com o aumento de CCS. / The overall objectve of this study was to evaluate risk factors associated with management practices and hygienic raw milk quality, and to caracterize the farmer\'s knowledge and opinions about mastitis control and milk quality. The specific objectives were to evaluate the risk factors associated with hygienic milk quality, to determine the effect of mastitis pathogens on raw milk quality and to assess the association between framers knowledge about mastitis control and somatic cell count (SCC) of bulk tank. Therefore, we proposed three experiments. For experiment 1, to evaluate management practices associated with hygienic quality of raw milk in dairy farms, 120 dairy herds were selected according to the geometric mean of the total bacterial count (TBC) from 10 milk samples collected during two consecutive months, which were distributed in two groups: high TBC (1.11 x104 CFU / mL, n = 60) and low TBC (4.4 x103 CFU / mL, n = 60). After selection of herds, milk samples were collected weekly for two months to perform analyzes of TBC, preliminary incubation count (PIC), laboratory pasteurization count (LPC), coliform count (CC), somatic cell count (SCC) and fat, protein and total solids concentrations. After laboratory analysis, 63 herds were visited for on-farm data collection by a questionnaire about: a) general aspects of farm management; b) milking management; c) milking equipment and utensils cleaning procedures; d) mastitis control; e) udder cleaning conditions. For experiment 2, to evaluate the knowledge and opinions of dairy farmers about mastitis control and milk quality, 63 herds were selected and distributed according to geometric means of SCC (8 weekly milk sampling during two consecutive months) into three groups: a) low SCC: &#8804; 250,000 cells / mL (n = 16); b) medium SCC: >250,000 &#8804; 400,000 cells / mL (n = 24); c) high SCC:> 400,000 cells / mL (n = 23). Previously formulated questionnaires were submitted to the herd manager, with questions about the following topics: socioeconomic characteristics, knowledge about SCC, TBC, mastitis and mastitis prevention practices. For experiment 3, to evaluate the association between mastitis pathogens, SCC and TBC, 90 herds were selected based on the SCC of 10 milk samples collected during two consecutive months, to compose the following groups: a) &#8804; 250,000 cells / mL (n = 30), b) >250,000 &#8804; 600,000 cells / mL (n = 30), c)> 600,000 cells / mL (n = 30). Bulk Tank milk samples were collected every 15 days for a period of three months, for Staphylococcus aureus count, Streptococcus agalactiae count, coagulase-negative staphylococci count, environmental streptococci count, Escherichia coli count, coliform count, TBC, SCC and fat, protein and total solids concentrations. The high amount of organic matter in the bulk tank outlet valve is a risk factor for the raw milk hygienic quality, the use of pre and post teat dipping is associated with a reduction of major indicators of raw milk hygienic quality and the presence of suckling calves before milking was associated with increased TBC, PIC and CC. Other social and economical factors, such as the milk as main economic activity in the farm, type of milking procedures used, the use of methods for mastitis detection and knowledge about legal requirements for SCC and TBC were correlated with CCS in bulk tank milk. Additionally, high Streptococcus agalactiae counts is associated with reduced bulk tank milk quality because of increased SCC.
96

Hållbarhet på kapillära blodprover för analys av hemoglobin, leukocyter och trombocyter / Shelf life for analysis of haemoglobin, leukocytes and platelets in capillary blood samples

Johansson, Sara January 2022 (has links)
Inom klinisk verksamhet är det av stor betydelse att känna till hållbarheten på olika analyter för att säkerställa att analysen inte genomförs på för gamla prover. Vid litteratursökning framgick att bland de publicerade studier som undersökt hållbarheten på blodprover har de flesta undersökt hållbarheten på venösa men inte kapillära blodprover. En vanligt förekommande analys med både venösa och kapillära prover är blodstatus, som inkluderar bland annat bestämning av hemoglobinkoncentrationen (Hb-), leukocyt- samt trombocytpartikelkoncentrationen (LPK och TPK). Analys av blodets celler kan ge allmän information om hälsotillståndet hos patienter och är därav viktiga och vanligt förekommande analyser. Syftet med examensarbetet var att undersöka hållbarheten för analyserna Hb, LPK och TPK på kapillära blodprover efter fyra och sex timmars förvaring i rumstemperatur. Provmaterialet utgjordes av 100 kapillära prover som analyserades på hematologiinstrumentet Sysmex XN-10. Analysmetoden för Hb var fotometri med natriumlaurylsulfat- (SLS-) metoden. LPK bestämdes med flödescytometri medan TPK bestämdes med impedansmetoden alternativt flödescytometri. Resultatet visade att det för Hb inte förekom någon signifikant statistisk skillnad mellan den initiala analysen och efter fyra respektive sex timmar. Analysresultatet för Hb var därmed stabilt under förhållandena i denna studie. För LPK och TPK förekom statistiskt signifikanta skillnader mellan resultatet vid den initiala analysen jämfört med efter fyra respektive sex timmar. Analysresultaten för LPK och TPK var därmed inte lika stabila som Hb är under förhållandena i studien. Den statistiska skillnaden bedömdes däremot inte ha någon klinisk betydelse, vilket ledde till slutsatsen är att kapillära prover för analys av Hb, LPK och TPK är hållbara i sex timmar vid förvaring i rumstemperatur. / One important factor in clinical practice is understanding the stability of analytes and for how long blood samples can be stored before analysis. Most published studies are based on venous blood samples rather than capillary. The knowledge about storage time for cells in capillary blood is therefore limited. Plenty of information can be obtained by analysing the blood cells and its components, including haemoglobin, white blood cells and platelets. These analyses are therefore some of the most common in clinical practice. The aim of this study was to evaluate the effect of the analysis result for haemoglobin, white blood cells and platelets in capillary blood samples after storage at room temperature for four and six hours, respectively. In the study, 100 capillary samples from anonymous patients were analysed with the haematology analyser Sysmex XN-10. The method for analysing haemoglobin was the sodium lauryl sulphate (SLS) detection method with spectrophotometry. White blood cells were analysed with fluorescens flow cytometry. Platelets were analysed with either impedance or fluorescens flow cytometry. The result of the study showed no statistically significant difference between the initial analysis results in haemoglobin and at four and six hours, concluding that within the conditions of this study, the analysis result for haemoglobin was stable. Significant statical differences were identified for both white blood cells and platelet analysis results at four and six hours. However, the identified statistical significance was not esteemed to have any clinical relevance. In conclusion haemoglobin, white blood cells and platelets in capillary blood can be stored for at least six hours at room temperature.
97

Study of bitwise operations on non-scarce attribute based data structures in PostgreSQL

Eschmann, Marcel January 2018 (has links)
This report investigates the viability of bitwise operations on non-scarce attribute based data structures in PostgreSQL. For applications where computation can’t be avoided, it most probably can be optimized. In an attempt of bringing the computation closer to hardware and the underlying data, operations directly on the database system are explored, taking inspiration from the research field of comparative genomics. With the case-study of an online job platform in mind, where possible matchings between candidate and job descriptions are calculated by a matching engine, a binary encoding is proposed and the computational components identified. The ultimate goal was to evaluate the scalability of the bitwise strategy with respect to the current matching engine. Through an iterative approach, this report conducts quantitative experiments on the presented components. Most notably, an implementation of the population count in the form of a C extension was introduced. It was found, that even for large sequence lengths, the operation is highly efficient. Among the chosen algorithms Lookup Table, Hamming Weight, Intrinsic functions and Unrolled Inline Assembly, the 64 bit intrinsic function displayed the best performance. Benchmarks determined, that the proposed bitwise approach is an excellent strategy for the outlined use-case. Despite the tradeoff of additional complexity in the encoding and decoding of data, the speedup is so significant, that the targeted user base of 100000 can easily be managed and allows for the deprecation of caching mechanisms. / Denna rapport undersöker gångbarheten för bitwise-operationer på icke-knappa attributbaserade datastrukturer i PostgreSQL. För applikationer där komputationen inte kan undvikas, kan den högst troligen optimeras. I ett försök att föra beräkningen närmare hårdvaran och den underliggande datan, undersöks operationer direkt på databasen med inspiration från forskningsområdet inom komparativ genomik. Med fallstudien av en online rekryteringsplattform i åtanke, där möjliga matchningar mellan kandidatoch arbetsbeskrivningar beräknas av en matchningsmotor, föreslås en binär kodning och komputationskomponenterna identifieras. Det slutgiltiga målet var att utvärdera skalbarheten hos bitwise-strategin med avseende till den aktuella matchningsmotorn. Genom ett iterativ tillvägagångssätt utför denna rapport kvantitativa experiment på de presenterade komponenterna. Framför allt infördes en implementering av population count i form av ett C-tillägg i databasen. Det visade sig att även för större sekvenslängder är operationen mycket effektiv. Bland de utvalda algoritmerna Lookup Table, Hamming Weight, Intrinsic-funktioner och Unrolled Inline Assembly, visade 64-bitars Intrisicfunktionen den bästa prestandan. Experimenten fastställde att det föreslagna bitwisetillvägagångssättet är en utmärkt strategi för den valda fallstudien. Trots avvägningen med ytterligare komplexitet vid kodning och avkodning av data är hastigheten så signifikant att ett användarantal på 100000 enkelt kan hanteras och möjliggör uteslutning av cache-mekanismer.
98

Text Mining Infrastructure in R

Meyer, David, Hornik, Kurt, Feinerer, Ingo 31 March 2008 (has links) (PDF)
During the last decade text mining has become a widely used discipline utilizing statistical and machine learning methods. We present the tm package which provides a framework for text mining applications within R. We give a survey on text mining facilities in R and explain how typical application tasks can be carried out using our framework. We present techniques for count-based analysis methods, text clustering, text classiffication and string kernels. (authors' abstract)
99

AN EXAMINATION OF MILK QUALITY EFFECTS ON MILK YIELD AND DAIRY PRODUCTION ECONOMICS IN THE SOUTHEASTERN UNITED STATES

Nolan, Derek T. 01 January 2017 (has links)
Mastitis is one of the most costly diseases to dairy producers around the world with milk yield loss being the biggest contributor to economic losses. The objective of first study of this thesis was to determine the impacts of high somatic cell counts on milk yield loss. To accomplish this, over one million cow data records were collected from Southeastern US dairy herds. The objective of the second study was to determine optimum treatment cost of clinical mastitis by combining two economic modeling approaches used in animal health economics. The last objective of this thesis was to determine how much Southeastern US dairy producers are spending to control milk quality on farm and determine if they understand how milk quality affects them economically. This was accomplished through a collaborative project within the Southeast Quality Milk Initiative.
100

Improving Image Based Fruitcount Estimates Using Multiple View-Points

Stein, Madeleine January 2016 (has links)
This master-thesis presents an approach to track and count the number of fruit incommercial mango orchards. The algorithm is intended to enable precision agri-culture and to facilitate labour and post-harvest storage planning. The primary objective is to develop an multi-view algorithm and investigate how it can beused to mitigate the effects of visual occlusion, to improve upon estimates frommethods that use a single central or two opposite viewpoints. Fruit are detectedin images by using two classification methods: dense pixel-wise cnn and regionbased r-cnn detection. Pair-wise fruit correspondences are established between images by using geometry provided by navigation data, and lidar data is used to generate image masks for each separate tree, to isolate fruit counts to individual trees. The tracked fruit are triangulated to locate them in 3D space, and spatial statistics are calculated over whole orchard blocks. The estimated tree counts are compared to single view estimates and validated against ground truth data of 16 mango trees from a Bundaberg mango orchard in Queensland, Australia. The results show a high R2-value of 0.99335 for four hand labelled trees and a highest R2-value of 0.9165 for the machine labelled images using the r-cnn classifier forthe 16 target trees.

Page generated in 0.0485 seconds