M. Tech. (Mechanical Engineering, Faculty of Engineering and Technology): Vaal University of Technology / Presently there exist a lot of controversies about the mechanical properties of nanomaterials. Several convincing reasons and justifications have been put forward for the controversies. Some of the reasons are varying processing routes, varying ways of defining equations, varying grain sizes, varying internal constituent structures, varying techniques of imposing strain on the specimen etc. It is therefore necessary for scientists, engineers and technologists to come up with a clearer way of defining and dealing with nanomaterials’ mechanical properties. The parameters of the internal constituent structures of nanomaterials are random in nature with random spatial patterns. So they can best be studied using random processes, specifically as stochastic processes. In this dissertation the tools of stochastic processes have been used as they offer a better approach to understand and analyse random processes. This research adopts the approach of ascertaining the correct mathematical models to be used for experimentation and modelling. After a thorough literature survey it was observed that size and temperature are two important parameters that must be considered in selecting the relevant mathematical definitions for nanomaterials’ mechanical properties. Temperature has a vital role to play during grain refinement since all severe plastic deformation involves thermomechanical processes. The second task performed in this research is to develop the mathematical formulations based on the experimental observation of 2-D grains and 3-D grains deformed by Accumulative Roll-Bonding and Equal Channel Angular Pressing. The experimental observations revealed that grains deformed by Accumulative Roll-Bonding and Equal Channel Angular Pressing are elongated when observed from the rolling direction, and transverse direction, and equiaxed when observed from the normal direction. In this dissertation, the different experimental observations for the grain size variants during grain refinement were established for 2-D and 3-D grains. This led to the development of a stochastic model of grain-elongation for 2-D and 3-D grains. The third task was experimentations and validation of proposed models. Accumulative Roll-Bonding, Equal Channel Angular Pressing and mechanical testing (tensile test) experiments were performed. The effect of size on elongation and material properties were studied to validate the developed models since size has a major effect on material’s properties. The fourth task was obtaining results and discussion of theoretical developed models and experimental results. The following facts were experimentally observed and also revealed by the models. Different approaches of measuring grain size reveal different strains that cannot be directly obtained from plots of the corresponding grain sizes. Grain elongation evolved as small values for larger grains, but became larger for smaller grains. Material properties increased with elongation reaching a maximum and started decreasing as is evident in the Hall-Petch to the Reverse Hall-Petch Relationship. This was alluded to the fact that extreme plastic straining led to distorted structures where grain boundaries and curvatures were in “non-equilibrium” states. Overall, this dissertation contributed new knowledge to the body of knowledge of nanomaterials’ mechanical properties in a number of ways. The major contributions to the body of knowledge by his study can be summarized as follows: (1) The study has contributed in developing a model of elongation for 2-D grain and 3-D grains. It has been generally reported by researchers that materials deformed by Accumulative Roll-Bonding and Equal Channel Angular Pressing are generally elongated but none of these researchers have developed a model of elongation. Elongation revealed more information about “size” during grain refinement. (2) The Transmission Electron Microscopy revealed the grain shape in three directions. The rolling direction or sliding direction, the normal direction and the transverse direction. Most developed models ignored the different approaches of measuring nanomaterials’ mechanical properties. Most existing models dealt only with the equivalent radius measurement during grain refinement. In this dissertation, the different approaches of measuring nanomaterials’ mechanical properties have been considered in the developed models. From this dissertation an accurate correlation can be made from microscopy results and theoretical results. (3) This research has shown that most of the published results on nanomaterials’ mechanical properties may be correct although controversies exist when comparing the different results. This research has also shown that researchers might have considered different approaches to measure nanomaterials’ mechanical properties. The reason for different results is due to different approaches of measuring nanomaterials’ mechanical properties as revealed in this research. Since different approaches of measuring nanomaterials’ mechanical properties led to different obtained results, this justify that most published results of nanomaterials’ mechanical properties may be correct. This dissertation revealed more properties of nanomaterials that are ignored by the models that considered only the equivalent length. (4) This research has contributed to the understanding of nanomaterials controversies when comparing results from different researchers.

The primary objective of this study was to determine the socio-economic impact of the Tsitsikamma National Park. Secondly, to determine the relationship between the community's level of interest in the Tsitsikamma National Park (TNP) and their perceptions concerning the environmental, economic and social impacts of the TNP. By conducting a literature study, the first objective was achieved. The following tourism impacts were identified: environmental, economic and social. These impacts, both positive and negative, were measured by means of a questionnaire. The goal of the questionnaire was to measure the communities' perceptions concerning the Tsitsikamma National Park and its impact on the local economy. Based on this, the aspects that needed clarity were the economic (monetary) value of the TNP in terms of tourists and park management spending as well as the size of the multiplier effect. Furthermore, the residents' perceptions regarding the TNP were identified as well as the benefits received from the TNP. Three surveys were conducted to achieve the goal of this study: a community survey (among the local residents of Nature's Valley and Storms River Village) to measure the tourism impacts; a business survey (including penrnanent local businesses in and around the TNP), and a visitor survey (tourists visiting the TNP) to measure the economic impacts as a result of the TNP. A total of 299 questionnaires were completed of which 132 represented the community survey, 11 the business survey and 156 the visitors' survey. Firstly, partial multipliers were derived through a process of iteration to determine the economic impact of the Tsitsikamma National Park. The total impact of the Tsitsikamma National Park on the local economy resulted in total spending being R45 359 784, an output effect of R50 002793, and finally an income effect of R21 723 510. Therefore, it was found that the TNP has a positive economic impact. Secondly, effect sizes were calculated, which involved the difference in means to determine the relationships between tourism impacts and product interest from the communities' perspectives. It was found that residents who visit the TNP more often have a more positive attitude towards the Tt\IP, which is important for the sustainability of the TNP as well as building positive relationships with the community. The positive impacts due to TNP that were found can be divided into three categories. Firstly, environmental impacts included improving the appearance of the area, conservation of natural resources, sustainability of the natural environment, increased awareness of nature, improvement of knowledge and preservation of water areas for recreation purposes. Secondly, positive economic impacts included an increase in employment opportunities, more investors focused on development in the surrounding areas, business development and tourism is promoted and money spent by tourists stimulates the economy. Lastly the positive social impacts that were identified included opportunities to relax and the park provides opportunities for people to have fun with their families and friends. / Thesis (M.Com. (Tourism))--North-West University, Potchefstroom Campus, 2010.

The primary objective of this study was to determine the socio-economic impact of the Tsitsikamma National Park. Secondly, to determine the relationship between the community's level of interest in the Tsitsikamma National Park (TNP) and their perceptions concerning the environmental, economic and social impacts of the TNP. By conducting a literature study, the first objective was achieved. The following tourism impacts were identified: environmental, economic and social. These impacts, both positive and negative, were measured by means of a questionnaire. The goal of the questionnaire was to measure the communities' perceptions concerning the Tsitsikamma National Park and its impact on the local economy. Based on this, the aspects that needed clarity were the economic (monetary) value of the TNP in terms of tourists and park management spending as well as the size of the multiplier effect. Furthermore, the residents' perceptions regarding the TNP were identified as well as the benefits received from the TNP. Three surveys were conducted to achieve the goal of this study: a community survey (among the local residents of Nature's Valley and Storms River Village) to measure the tourism impacts; a business survey (including penrnanent local businesses in and around the TNP), and a visitor survey (tourists visiting the TNP) to measure the economic impacts as a result of the TNP. A total of 299 questionnaires were completed of which 132 represented the community survey, 11 the business survey and 156 the visitors' survey. Firstly, partial multipliers were derived through a process of iteration to determine the economic impact of the Tsitsikamma National Park. The total impact of the Tsitsikamma National Park on the local economy resulted in total spending being R45 359 784, an output effect of R50 002793, and finally an income effect of R21 723 510. Therefore, it was found that the TNP has a positive economic impact. Secondly, effect sizes were calculated, which involved the difference in means to determine the relationships between tourism impacts and product interest from the communities' perspectives. It was found that residents who visit the TNP more often have a more positive attitude towards the Tt\IP, which is important for the sustainability of the TNP as well as building positive relationships with the community. The positive impacts due to TNP that were found can be divided into three categories. Firstly, environmental impacts included improving the appearance of the area, conservation of natural resources, sustainability of the natural environment, increased awareness of nature, improvement of knowledge and preservation of water areas for recreation purposes. Secondly, positive economic impacts included an increase in employment opportunities, more investors focused on development in the surrounding areas, business development and tourism is promoted and money spent by tourists stimulates the economy. Lastly the positive social impacts that were identified included opportunities to relax and the park provides opportunities for people to have fun with their families and friends. / Thesis (M.Com. (Tourism))--North-West University, Potchefstroom Campus, 2010.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-06-29T14:16:18Z No. of bitstreams: 1 ISIS TATIANE DE BARROS MACÊDO VELOSO - TESE (PPGCEMat) 2016.pdf: 3573054 bytes, checksum: bfcbdc962777a12887f4d94980048582 (MD5) / Made available in DSpace on 2018-06-29T14:16:18Z (GMT). No. of bitstreams: 1 ISIS TATIANE DE BARROS MACÊDO VELOSO - TESE (PPGCEMat) 2016.pdf: 3573054 bytes, checksum: bfcbdc962777a12887f4d94980048582 (MD5) Previous issue date: 2016-06-30 / A reciclagem de vidros surge como alternativa ao impacto causado pelo seu descarte no meio ambiente, contribuindo para preservação dos recursos naturais, redução na emissão de gases e diminuição no volume dos aterros e lixões. O vidro pode ser infinitamente reciclado, sem que haja perda de massa ou de suas propriedades. Além disso, destaca-se pela sua beleza, por ser um dos poucos materiais capazes de refletir luz, cuja aplicação pode resultar em produtos de elevado apelo estético. Esta pesquisa tem como objetivo o desenvolvimento de pastilhas para revestimento pelo processo de reciclagem de resíduos de vidros sódico-cálcicos, a partir de estudos de tratamento térmico de fusão e recozimento. Inicialmente, os vidros foram separados por cor, triturados manualmente, distinguidos em diferentes granulometrias e acondicionados em moldes de concreto celular. Em seguida, foram submetidos a diferentes tratamentos térmicos, que resultaram na fusão e recozimento, este último processo para minimizar as tensões internas que fragilizam o vidro. Desta forma, buscou-se analisar a influência das granulometrias e dos tratamentos térmicos sobre os aspectos visuais das peças; os estudos dos materiais dos moldes e sua interação com o vidro, a desmoldabilidade e o acabamento das pastilhas; os equipamentos utilizados para a cominuição dos cacos de vidro. Como resultados, definiu-se o tratamento térmico quatro (TT4) para os vidros incolores e o tratamento térmico cinco (TT5) para os vidros coloridos (azul, âmbar, verde claro e verde escuro), em busca de obter peças de textura enrugada, aspecto vítreo e superfície brilhosa. Quanto ao tratamento térmico, as análises realizadas por microscopia óptica mostraram a eliminação das tensões internas que fragilizam o vidro, assim como o teste de impacto demonstrou uma maior resistência ao choque para amostras com recozimento, comprovando, assim, sua eficácia. Quanto à viabilidade de produção, os resultados demonstraram que as pastilhas são passíveis de serem confeccionadas pelo grupo CAVI, em escala artesanal, utilizando tecnologias e recursos acessíveis ao grupo, numa perspectiva de tecnologia social. / Glass recycling is an alternative to the impact caused by its disposal in environment, contributing to preservation of natural resources, reduction in gas emissions and decrease in volume of landfills and dumps. Glass can be recycled endlessly without any loss of mass or its properties. In addition, stands out for its beauty, for being one of few materials capable of reflecting light, the implementation of which may result in high aesthetic appeal products. This research aims to develop glass pastilles for coatings by recycling process of sodium-calcium glass residues, from heat treatment studies of melting and annealing. Initially, glasses were separated by color, manually grinded, distinguished into different granulometries and conditioned in cellular concrete molds. Then were subjected to different heat treatments, which resulted in melting and annealing, the latter process to minimize the internal tensions that weaken glass. Thus, it sought to analyze the influence of grain size and thermal treatments of visual aspects of the pieces; studies of materials of molds and their interaction with glass, demoldability and finish of the tablets; equipment used for comminution of the glass. As a result, it defined the heat treatment four (TT4) for colorless glass and heat treatment five (TT5) for tinted (blue, amber, light green, dark green) in seeking to obtain pieces of wrinkled texture, glassy and glossy surface. About heat treatment, the analysis performed by optical microscopy showed elimination of internal stresses which weaken the glass, and impact test showed a greater shock resistance for samples annealed, confirming thus its effectiveness. As for viability of production, results showed that pastilles are likely to be made by CAVI group, artisanal scale, using technologies and resources accessible to the group, in a perspective of social technology.

Submitted by Erika Squisato Fernandes (erikasqui@hotmail.com) on 2018-09-17T20:08:35Z No. of bitstreams: 1 Dissertação-Erika-Final.pdf: 1681682 bytes, checksum: 0d3d284e39457ce899938fd565441dcf (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-09-18T12:11:13Z (GMT) No. of bitstreams: 1 fernandes_es_me_rcla.pdf: 1649309 bytes, checksum: 418254e846e33c3699727d682a1a4252 (MD5) / Made available in DSpace on 2018-09-18T12:11:13Z (GMT). No. of bitstreams: 1 fernandes_es_me_rcla.pdf: 1649309 bytes, checksum: 418254e846e33c3699727d682a1a4252 (MD5) Previous issue date: 2018-07-24 / O bagaço de cana-de-açúcar é um subproduto da indústria sucroalcooleira, majoritariamente usado para a cogeração de energia térmica e elétrica, através de sua combustão em caldeiras. Em função da sua composição em carboidratos vem sendo estudado na conversão em biocombustíveis. Porém, a recalcitrância da matriz lignocelulósica dificulta desestruturação do material, com baixa acessibilidade à celulose, influenciando na sacarificação enzimática. Neste contexto, o objetivo deste trabalho foi avaliar o efeito do pré-tratamento ácido diluído (10 %, m/m, 121 °C/30 min) em diferentes granulometrias, 16, 24, 35, 60 mesh e fundo de bagaço e fração externa (contendo epiderme) do colmo de cana-de-açúcar. Cada biomassa de cana-de-açúcar, em diferentes granulometrias, passou pelo pré-tratamento ácido diluído (10 %, m/m, 121° C/30 min). As amostras foram caracterizadas quanto ao seu conteúdo de celulose, hemicelulose e lignina. A área superficial de lignina foi determinada com a adsorção do corante catiônico Azure B em solução de 0,1 g.L-1. A determinação de acessibilidade à celulose foi realizada com corantes Direct Orange (superfície específica externa) e Direct Blue (superfície específica interna). A hidrólise enzimática (15 FPU.g-1 durante 24 h – Cellic Cetec 2 – Novozymes) foi aplicada nos materiais para avaliar o rendimento em glicose. Para o material retido na peneira de abertura 16 mesh, maior tamanho de partículas, a massa recuperada de bagaço foi de 59,81 % e no fundo, menor tamanho de partícula, foi de 53,92 %. A fração externa apresentou as recuperações de massas de 37,12 % e 31,42 %, nas mesmas peneiras. O bagaço e a fração externa apresentaram valores próximos na liberação de xilose. Nos materiais retidos na peneira de abertura de 24 mesh, foi solubilizado 0,27 g.L-1 de xilose no bagaço e na fração externa 0,26 g.L-1. O emprego do corante catiônico Azure B não demonstrou uma maior área superficial de lignina com a diminuição do tamanho de partícula, apresentando a maior área superficial de lignina para o bagaço de 10,98 m2.g-1, e fração externa de 10,21 m2.g-1, no material retido na peneira com abertura de 16 mesh. A determinação de acessibilidade à celulose com os corantes Direct Blue e Direct Orange indicaram com diminuição do tamanho de partículas provocou aumento de acessibilidade à celulose. As frações de menor tamanho de partículas, 60 mesh, apresentaram uma adsorção do Direct Orange 667 mg.g-1 e o Direct Blue 556 mg.g-1 para o bagaço, a fração externa apresentou 833 mg.g-1 na adsorção dos dois corantes. A hidrólise enzimática apresentou uma conversão em glicose no bagaço de 75,41 % e na fração externa 33,69 %, no material retido no fundo, os menores tamanhos de partícula. O uso do pré-tratamento ácido diluído melhora o aumento na acessibilidade à celulose, resultando em melhor ação das enzimas na hidrólise enzimática nos menores tamanhos de partículas 35, 60 mesh e fundo. / Sugarcane bagasse is a by-product of the sugar and alcohol industry, mostly used for cogeneration of thermal and electric energy, through its combustion in boilers. Due to its composition in carbohydrates has been studied in the conversion to biofuels. However, the recalcitrance of the lignocellulosic matrix makes it difficult to disintegrate the material, with low accessibility to the cellulose, influencing the enzymatic saccharification. In this context, the objective of this work was to evaluate the effect of diluted acid pretreatment (10 %, m/m, 121 °C / 30 min) in different granulometries, 16, 24, 35, 60 mesh and background bagasse and fraction (containing epidermis) from the sugar cane stalk. Each biomass of sugarcane, in different granulometries, underwent the pre-treatments diluted acid (10 %, m/m, 121 °C / 30 min). The samples were characterized for their content of cellulose, hemicellulose and lignin. The surface area of lignin was determined with the adsorption of the cationic dye Azure B in solution of 0.1 g.L-1. The determination of accessibility to the cellulose was performed with Direct Orange (specific external surface) and Direct Blue (specific internal surface) dyes. Enzymatic hydrolysis (15 FPU.g-1 for 24 h - Cellic Cetec 2 - Novozymes) was applied to the materials to evaluate glucose yield. For the material retained in the 16 mesh aperture sieve, larger particle size, the recovered mass of bagasse was 59.81 % and in the bottom, smaller particle size was 53.92 %. The external fraction presented the recoveries of masses of 37.12 % and 31.42 %, in the same sieves. The bagasse and the outer fraction presented close values in the release of xylose. In the materials retained in the 24 mesh sieve, 0.27 g.L-1 of xylose was solubilized in the bagasse and in the outer fraction 0.26 g.L-1. The use of the cationic dye Azure B did not demonstrate a larger surface area of lignin with the decrease of the particle size, presenting the highest ASL for the bagasse of 10.98 m2.g-1, and external fraction of 10.21 m2.g -1, in the material retained in the 16 mesh screen. The determination of accessibility to the cellulose with the Direct Blue and Direct Orange dyes indicated with decrease of the particle size caused increase of accessibility to the cellulose. The smaller fraction of particles, 60 mesh, had an adsorption of Direct Orange 667 mg.g-1 and Direct Blue 556 mg.g-1 for the bagasse, the external fraction presented 833 mg.g-1 in the adsorption of two dyes. The enzymatic hydrolysis showed a glucose conversion in the bagasse of 75.41 % and in the outer fraction 33.69 %, in the material retained in the bottom, the smaller particle sizes. The use of dilute acid pretreatment improves the increase in cellulose accessibility, resulting in better enzyme action on enzymatic hydrolysis in the smaller particle sizes of 35, 60 mesh and background.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-31T17:34:37Z No. of bitstreams: 1 thiagoboubeecardozo.pdf: 664105 bytes, checksum: c76b7de470f214d95d3054d0ac7b8232 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-01T11:40:26Z (GMT) No. of bitstreams: 1 thiagoboubeecardozo.pdf: 664105 bytes, checksum: c76b7de470f214d95d3054d0ac7b8232 (MD5) / Made available in DSpace on 2017-06-01T11:40:26Z (GMT). No. of bitstreams: 1 thiagoboubeecardozo.pdf: 664105 bytes, checksum: c76b7de470f214d95d3054d0ac7b8232 (MD5) Previous issue date: 2013-05-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A Internet é um sistema em contínua evolução. Nesta dissertação, é caracterizada e analisada a recente evolução da conectividade fim-a-fim da Internet, comparando métricas importantes ao desempenho fim-a-fim de dois períodos distintos separados por 5 anos. Os resultados mostram que a distribuição do tamanho médio dos caminhos se mantém pouco alterada de 2006 para 2011, mas a distribuição do atraso acabou piorando, com um aumento de 45% no atraso dos caminhos de 2006 para 2011. Isso afeta diretamente o desempenho e degrada a experiência do usuário. Além disso, é mostrado que a diversidade de caminhos diminuiu e, com isso, os caminhos distintos ficaram um pouco mais similares. Esse resultado tem um impacto direto nos algoritmos de roteamento que tentam explorar a diversidade de caminhos para uma maior tolerância a falhas. Depois foi estudado mais a fundo o fenômeno conhecido como bufferbloat, que é uma das possíveis causas do aparente aumento da latência. Os resultados mostraram que filas muito grandes podem impactar fortemente no desempenho da rede, mas também indicaram que provavelmente o problema não irá ocorrer em máquinas Unix Like com as configurações padrão. / The Internet is a system under continuous evolution. In this dissertation, it is characte rized and analyzed the recent end-to-end connectivity evolution of the Internet, comparing key end-to-end performance metrics from two distinct periods separated by five years. The findings show that the average path length distribution remains virtually unchanged from 2006 to 2011, but the delay distribution actually became worse, with a 45% increase in path delay from 2006 to 2011. This directly affects network performance and degrades user experience. Furthermore, it is shown that path diversity decreased, and accordingly, distinct paths became slightly more similar. This result has a direct impact on routing algorithms that try to explore path diversity to become more fault-tolerant. Later it was studied more deeply the phenomenon known as bufferbloat, which is one of the possible causes of the apparent increase of latency. The results show that large buffers can strongly degrade the network performance, but they also show that the problem is not likely to occur in Unix Like machines with default settings.

The Central Limpopo River Valley elephant population is a cross border population on which very little scientific data pertaining to numbers, distribution and demographic status is available. The total range was determined using published literature, reports, postal questionnaires and interviews. Numbers and dry season distribution were determined by means of three total aerial counts in 2000, 2001 and 2004 of the sections of the total range in which elephants were reported. Totals of 1388, 1424 and 1339 were recorded with the highest numbers in all counts in the Botswana section of the study area. Four sub groups within the population were identified. Human settlements and the distribution of rivers and fencing appeared to be the major factors influencing distribution and movement. The population is highly mobile within the total range, and numbers fluctuate markedly in any given section, but numbers in the total range appear to have been increasing slowly at below 2% per annum and the range expanding slightly over the last 30 years. Additional range is being provided by the creation of a Trans Frontier Conservation Area. Movements were determined through ground observations within the study area and seem to follow the major rivers namely the Shashe, Ramokgwabane, Simukwe, Shashani, Tuli, Umzingwane and Limpopo rivers. The social and demographic status of the population was determined through ground observations as well as total aerial counts conducted within the Northern Tuli Game Reserve from 1976 to 2004. The study has shown that group sizes increase with an increase in rainfall (average mean group size of 56.524, SDE 77.388) and decrease during low rainfall periods (mean group size of 24.157, SDE 22.223). The age structure was determined from aerial photographs during August 2000 and showed a high percentage of adults and sub adults, with infants estimated at 3%. The approximate birth rate (1.5%) calculated for 2000 is balanced by an average natural mortality determined between 1999 and 2004 of 1.8%. The inter calf interval determined from known herds observed in the Northern Tuli Game Reserve was estimated at 3.94% and suggests that the long-term birth rate for the population should be higher than that for the year 2000. The difference between the combined natural and human induced mortality rates (~4%) and the birth rate suggested by the age structure and the inter calf interval (~6%) gives the ~2% long-term increase observed in the numbers. Human elephant interactions within the study area were determined through published literature and interviews with local residents. Elephants and humans interact in both a positive and negative manor and interactions are related to human land use practices within the area. Elephants were indicated as the major problem animal in farming areas, but the major draw card within tourism operations. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2008. / Animal and Wildlife Sciences / unrestricted

Traditional latent class analysis (LCA) considers entropy R2 as the only measure of effect size. However, entropy may not always be reliable, a low boundary is not agreed upon, and good separation is limited to values of greater than .80. As applications of LCA grow in popularity, it is imperative to use additional sources to quantify LCA classification accuracy. Greater classification accuracy helps to ensure that the profile of the latent classes reflect the profile of the true underlying subgroups. This Monte Carlo study compared the quantification of classification accuracy and confidence intervals of three effect sizes, entropy R2, I-index, and Cohen’s d. Study conditions included total sample size, number of dichotomous indicators, latent class membership probabilities (γ), conditional item-response probabilities (ρ), variance ratio, sample size ratio, and distribution types for a 2-class model. Overall, entropy R2 and I-index showed the best accuracy and standard error, along with the smallest confidence interval widths. Results showed that I-index only performed well for a few cases.

El presente trabajo de investigación académica está basado en el análisis de las acciones de la promoción digital en relación con el proceso de compra de ropa Plus Size en mujeres de 18 a 34 años de NSE B de Lima Metropolitana. En primer lugar, se dan a conocer cuales son las estrategias SEO y SEM, así mismo detalla cuales son las acciones comprendidas dentro de estas estrategias. Además, se investiga sobre la reacción del target a estas acciones y estímulos. En segundo lugar, se tomó muy en cuenta el análisis del proceso de compra de las mujeres del segmento, descubriéndose que el target prefiere realizar compras por internet antes que las tiendas físicas. Finalmente, se contrastaron ambas variables y se evaluó la influencia de las diferentes estrategias de marketing digital en las etapas del proceso de compra del segmento Plus Size. Adicionalmente, se presenta el contraste de los resultados con la hipótesis planteada y conclusiones de la investigación. / This academic research work is based on the analysis of the actions of digital promotion in relation to the process of buying Plus Size clothing in women from 18 to 34 years of age from NSE B of Metropolitan Lima. First of all, they are disclosed which are the SEO and SEM strategies, as well as detailing what are the actions included within these strategies. In addition, the target's reaction to these actions and stimuli is investigated. Secondly, I am very aware of the analysis of the purchasing process of women in the segment, discovering that the objective of making purchases online before physical stores. Finally, both variables were compared and the influence of the different digital marketing strategies in the stages of the Plus Size segment purchasing process was evaluated. In addition, the contrast of the results with the hypotheses and the conclusions of the investigation is presented. / Trabajo de investigación

Ubiquitous Internet of Things (IoT) is destined to connect everybody and everything on a never-before-seen scale. Such networks, however, have to tackle the inherent issues created by the presence of very heterogeneous data transmissions over the same shared network. This very diverse communication, in turn, produces network packets of various sizes ranging from very small sensory readings to comparatively humongous video frames. Such a massive amount of data itself, as in the case of sensory networks, is also continuously captured at varying rates and contributes to increasing the load on the network itself, which could hinder transmission efficiency. However, they also open up possibilities to exploit various correlations in the transmitted data due to their sheer number. Reductions based on this also enable the networks to keep up with the new wave of big data-driven communications by simply investing in the promotion of select techniques that efficiently utilize the resources of the communication systems. One of the solutions to tackle the erroneous transmission of data employs linear coding techniques, which are ill-equipped to handle the processing of packets with differing sizes. Random Linear Network Coding (RLNC), for instance, generates unreasonable amounts of padding overhead to compensate for the different message lengths, thereby suppressing the pervasive benefits of the coding itself. We propose a set of approaches that overcome such issues, while also reducing the decoding delays at the same time. Specifically, we introduce and elaborate on the concept of macro-symbols and the design of different coding schemes. Due to the heterogeneity of the packet sizes, our progressive shortening scheme is the first RLNC-based approach that generates and recodes unequal-sized coded packets. Another of our solutions is deterministic shifting that reduces the overall number of transmitted packets. Moreover, the RaSOR scheme employs coding using XORing operations on shifted packets, without the need for coding coefficients, thus favoring linear encoding and decoding complexities. Another facet of IoT applications can be found in sensory data known to be highly correlated, where compressed sensing is a potential approach to reduce the overall transmissions. In such scenarios, network coding can also help. Our proposed joint compressed sensing and real network coding design fully exploit the correlations in cluster-based wireless sensor networks, such as the ones advocated by Industry 4.0. This design focused on performing one-step decoding to reduce the computational complexities and delays of the reconstruction process at the receiver and investigates the effectiveness of combined compressed sensing and network coding.