Meta-Analysis Study: Effect of Means Ends Analysis (MEA) Model on Student's Mathematical Problem-Solving Skills

A comprehensive review of Means Ends Analysis (MEA) impact on mathematical problem-solving skills has not been studied extensively, As a result, few teachers are aware of the benefits that this approach has for children. This meta-analysis study was conducted to assess the overall impact of teaching students to solve mathematical problems using the MEA approach. Empirical information was obtained from URL links, Semantic Scholar, and Google Scholar. The search produced 18 articles that were written between 2009 and 2023. 18 items were eligible for analysis because they met the inclusion criteria. In the analysis tool, a random estimation model and Comprehensive Meta-Analysis (CMA) software are both utilized. The outcomes showed that the overall effect size of the study was 0.920. These results imply that the use of the MEA has a significant impact on students' mathematical problem-solving skills. After examining the moderator variables, it was found that the MEA model was successful when considering student sample sizes, but not when considering the educational level and demographics of the students. The application of MEA in enhancing students' mathematical problem-solving should be employed more frequently, particularly in elementary schools, according to this meta-analysis study's advice to Indonesian math teachers

Assessment and development of mitigation strategies for membrane durability in fuel cells

Fuel cell membranes undergo simultaneous or individual chemical and mechanical degradation under dynamic fuel cell operating conditions. This combined stress development effect compromises the functionality of the membrane and ultimately, the overall durability of the fuel cell system. Therefore, it is critical to understand the underlying degradation mechanisms and failure modes under operational conditions. In this thesis, an extensive research methodology including accelerated stress tests, visualization techniques, and finite element modeling is adopted in order to understand and mitigate membrane degradation. The membrane characterization is facilitated using a non-invasive laboratory-based X-ray computed tomography (XCT) system for 3D visualization of membrane damage progression over the lifetime of the fuel cell. The 3D XCT approach is first applied to understand the degradation mechanism responsible for combined chemical and mechanical membrane degradation. The XCT approach is further expanded to 4D in situ visualisation through periodic same location tracking within a miniature operational fuel cell. Fuel cell membranes with mechanical reinforcements and chemical additives are tested as existing mitigation strategies for the isolated degradation stressors. Under pure chemical degradation, the chemically and mechanically reinforced membrane does not show membrane thinning or shorting sites and exceeds the lifetime of the non-reinforced membrane by 2x. The reinforced membrane also mitigated/delayed the crack development during pure mechanical degradation as compared to the non-reinforced membrane. However, significant membrane degradation is still observed and attributed to buckling and delamination mechanisms within the membrane electrode assembly (MEA). Mitigation of these mechanisms is demonstrated through two novel approaches proposed in this thesis: i) reduced surface roughness gas diffusion layers (GDLs); and ii) bonded MEAs. Both mitigation strategies are tested using the same experimental workflow and shown to provide substantial mitigation against fatigue driven mechanical membrane degradation via reduced membrane buckling, resulting in a doubling of the test lifetime in each case. Complementary finite element simulations corroborate the experimental findings and further estimate the critical GDL void sizes to prevent membrane buckling and the required interfacial MEA adhesion quality to stabilize the MEA for improved membrane durability

The role of 4th industrial revolution technologies in driving competitive advantage in the South African beverage manufacturing industry

Fourth industrial revolution technology (4IR-T) applications are associated with benefits such as cost efficient measures to enhance productivity, use of effective communication channels to improve relationships between businesses and customers, and the potential to drive sustainable competitive advantage. However, organisations within South Africa’s beverage manufacturing industry are slow to adopt 4IR-T. This research aimed to explore the role of 4IR-T in driving competitive advantage within beverage manufacturing organisations in the FMCG industry of South Africa. The objective of this research was to determine how 4IR-T can be used to enhance competitive advantage within beverage manufacturing organisations hence, the research question, how can 4IR-T drive competitive advantage in beverage manufacturing organisations, guided this research. This qualitative research used a case study strategy to collect data from a beverage manufacturing organisation in South Africa via semi-structured interviews and a focus group. A purposive sampling method was applied to select twelve participants that included middle, senior and executive managers who have decision making power. A thematic analysis of the data was conducted, and the TechnologyOrganisation-Environment (TOE) framework was used as a lens to determine the role of 4IR-T in driving competitive advantage with beverage manufacturing organisations. A focus group was further performed to conduct member checking. Findings and discussion revealed various TOE factors that either promote or inhibit the adoption of 4IR-T. Perceived benefits, relative advantage, current state of competitive advantage and 4IR-T characteristics were factors found to enable 4IR-T adoption from a Technology and organisational perspective. However, barriers mostly from an organisation perspective were found, such as insufficient capital investment, cost of 4IR-T, inadequate skills capacity, which inhibit and slow the adoption of 4IR-T. Risks from an environmental perspective also inhibited the adoption of 4IR-T such as loadshedding, labour regulations and job redundancy. These barriers and risks thus, inhibit the drive for competitive advantage within the beverage manufacturing organisation. This study concludes and recommends that beverage organisations increase the speed with which they adopt 4IR-T by investing with a long-term focus, training, and upskilling employees, top management promoting 4IR-T with a digital strategy and the organisation using 4IR-T to prevent supply chain disruptions

A process for managing benefits of mobile enterprise applications in the insurance industry

Mobile enterprise applications (MEAs) are found in increasing numbers in organisations as smart-devices become an everyday necessity amongst employees and customers. Large amounts are invested in these applications, so it is important to see the value in improved business processes and the consequential improvement in business performance. Realising the benefits from their use is important to obtain the value from these investments. Yet, benefits management (BM) is poorly implemented in companies and a first step to improve this situation is to improve the visibility of the benefits that can be achieved by using MEAs. Hence the primary question asked in this study is “How can MEA benefits be successfully realised?” The strategy used to answer the question was action research in a single organisation using three MEAs in two different action research cycles. The study was conducted in a short-term insurance company in the Western Cape of South Africa with an established IT and project capability. Globally, the short-term insurance industry is under a significant threat from disruption by market entrants who don’t have to navigate legacy systems and who are more agile with their product offerings. Traditional insurers are looking for innovative solutions to transform the way in which insurance is sold and serviced. A BM process, which was modified from the literature, was refined through action cycles in three MEA projects to improve benefits realisation. The result showed that for MEA projects, which are not very large investments relative to other IT projects, a lighter, less cumbersome process was more practical and acceptable in the organisation. The creation of a benefits and risks template, during the action cycles, helped the organisation to build stronger business cases for MEA projects and also allowed for more comprehensive benefit identification, measurement and tracking, ultimately realising business performance improvements. The study also used a survey amongst 88 brokers and assessors to determine the factors which influence their adoption of these MEAs. The most significant factors influencing user adoption were the company’s willingness to fund the smart-devices, the ease of use of the MEA, job relevance and location dependence. A limitation of this study is that the organisation has a particular approach to project funding whereby the importance of BM is weighed against the cost of the project, hence BM is more important for very expensive projects. While the model prescribed in this study was sufficient in this context, it may not be suitable for organisations that are more conscientious about BM. This model would need to be tested in other contexts for transferability. A further limitation was the duration of time available for conducting this study because this was a PhD research project. Further action cycles might have refined the process further. The findings from this study are relevant to researchers and to organisations wanting to deploy MEAs. The BM process defined in this study can be used in MEA projects as a process to manage the identified benefits and ensure that they are realised. The benefits template can be used as a first step in the BM process to build the business case and the risks template can be used to identify potential problems that could hinder benefits realisation and can used to put mitigating actions in place to prevent problems to benefits realisation. The identification of factors influencing adoption of MEA can help organisations focus on these factors to ensure that their MEAs are used and they thereby derive benefits. The theoretical contributions of this study are a process model for the BM body of knowledge and a model explaining the factors influencing symbolic adoption of MEA. The identification and description of benefits and risks extends the body of knowledge for mobile applications research. These specific issues in the context of MEAs in the short-term insurance industry are understudied

Microchannel enhanced neuron-computer interface: design, fabrication, biophysics of signal generation, signal strength optimization, and its applications to ion-channel screening and basic neuroscience research

En el presente trabajo, utilizamos técnicas de microfabricación, simulaciones numéricas, experimentos de electrofisiología para explorar la viabilidad en me- jorar la interface ordenador-neurona a través de microcanales, y la biofísica para la generación de señales en los dispositivos con microcanales. También demos- tramos que los microcanales pueden ser usados como una técnica prometedora con alto rendimiento en el muestreo automático de canales iónicos a nivel subce- lular. Finalmente, se ha diseñado, fabricado y probado el micropozo-microcanal como modificación adicional a los arreglos de multielectrodos, permitiendo una alta ganancia en la relación señal/ ruido (en inglés Signal to Noise Ratio SNR), y el registro de múltiples-lugares en poblaciones de baja densidad de redes neu- ronales del hipocampo in vitro. Primero, demostramos que son de alto rendimiento los microcanales de bajo costo con interface neurona-electrodo, para el registro extracelular de la activi- dad neuronal con baja complexidad, por periodos estables de larga duración y con alta ganancia SNR. En seguida, se realiza un estudio mediante experimentos y simulaciones nu- méricas de la biofísica para la generación de las señales obtenidas de los dispositi- vos con microcanales. Basados en los resultados, racionalizamos y demostramos como es que la longitud del canal (siendo 200 μm) y la sección transversal del microcanal (siendo 12 μm2) canaliza a los potenciales de acción para estar dentro del rango de milivolts. A pesar del bajo grado de complexidad envuelto en la fabricación y aplicación, los dispositivos con microcanales otorgan una sola media de valor SNR de 101 76, lo cual es favorablemente comparable con la SNR que se obtiene de desarrollos recientes que emplean electrodos curados con CNT y Si-NWFETs. Más aún, nosotros demostramos que el microcanal es una técnica promete- dora para el alto rendimiento del muestro automático de canales iónicos a nivel subcelular: (1) Información experimental y simulaciones numéricas sugieren que las señales registradas sólo afectan los parches membranales localizados dentro del microcanal o alrededor de 100 μm de las entradas del microcanal. (2) La transferencia de masa de los componentes químicos en los microcanales fue ana- lizada por experimentos y simulaciones FEM. Los resultados muestran que los microcanales que contienen glía y tejido neuronal pueden funcionar como barre- ra de fluido/química. Los componentes químicos pueden ser solamente aplicados a diferentes compartimentos a nivel subcelular. Finalmente, basado en simulaciones numéricas y resultados experimentales, se propone que del micropozo-microcanal, obtenido de la modificación de MEA (MWMC-MEA), la longitud óptima del canal debe ser 0,3 mm y la posición 1 óptima del electrodo intracanal, hacia la entrada más cercana del microcanal, debe ser 0,1 mm. Nosotros fabricamos un prototipo de MWMC-MEA, cuyo hoyo pasante sobre las películas de Polydimethylsiloxane (PDMS) fue microtrabajado a través de la técnica de grabados reactivos de plasma de iones. La baja densidad del cultivo (57 neuronas /mm2) en el MWMC-MEAs permitió que las neuronas vivieran al menos 14 días, con lo que la señal neuronal con la máxima SNR obtenida fue de 142. 2In this present work, we used microfabrication techniques, numerical simulations, electrophysiological experiments to explore the feasibility of enhancing neuron-computer interfaces with microchannels and the biophysics of the signal generation in microchannel devices. We also demonstrate the microchannel can be used as a promising technique for high-throughput automatic ion-channel screening at subcellular level. Finally, a microwell-microchannel enhanced multielectrode array allowing high signal-to-noise ratio (SNR), multi-site recording from the low-density hippocampal neural network in vitro was designed, fabricated and tested. First, we demonstrate using microchannels as a low-cost neuron-electrode interface to support low-complexity, long-term-stable, high SNR extracellular recording of neural activity, with high-throughput potential. Next, the biophysics of the signal generation of microchannel devices was studied by experiments and numerical simulations. Based on the results, we demonstrate and rationalize how channels with a length of 200 μm and channel cross section of 12 μm2 yielded spike sizes in the millivolt range. Despite the low degree of complexity involved in their fabrication and use, microchannel devices provided a single-unit mean SNR of 101 76, which compares favourably with the SNR obtained from recent developments employing CNT-coated electrodes and Si-NWFETs. Moreover, we further demonstrate that the microchannel is a promising technique for high-throughput automatic ion-channel screening at subcellular level: (1) Experimental data and numerical simulations suggest that the recorded signals are only affected by the membrane patches located inside the microchannel or within 100 μm to the microchannel entrances. (2) The mass transfer of chemical compounds in microchannels was analyzed by experiments and FEM simulations. The results show that the microchannel threaded by glial and neural tissue can function as fluid/chemical barrier. Thus chemical compounds can be applied to different subcellular compartments exclusively. Finally, a microwell-microchannel enhanced MEA (MWMC-MEA), with the optimal channel length of 0.3 mm and the optimal intrachannel electrode position of 0.1 mm to the nearest channel entrance, was proposed based on numerical simulation and experiment results. We fabricated a prototype of the MWMCMEA, whose through-hole feature of Polydimethylsiloxane film (PDMS) was micromachined by reactive-ion etching. The low-density culture (57 neurons/mm2) were survived on the MWMC-MEAs for at least 14 days, from which the neuronal signal with the maximum SNR of 142 was obtained