M.Ed. (Educational Leadership) / The purpose of this study was: A. To discuss the term slow learner and to identify certain problems experienced by the slow learner. B. To identify specific problems experienced by the parents of the slow learner. C. To design a parent guidance programme for the head of the guidance department to aid Afrikaans speaking parents of the slow learner to accept their child and to try and solve the problems that their child experiences. D. To evaluate the effectiveness of the parent guidance programme. In evaluating the effectiveness of the parent guidance programme, the specific aims of the study were: - To ascertain what kind of parenting style the parents were using. - To teach the parents the advantage of the democratic parenting style. - To ascertain how the selfimages of the parents have improved in attending the programme. - To design guidelines for the parents how to cope with problems existing in the relationship between parent and child such as: * how to cope with conflict, * how to communicate effectively, * how to motivate the slow learner to become a successful student, * how to improve the selfconcept of the slow learner, and * how to cope with discipline. The Head of the Guidance department has a very important role to play in the establishing of such a parent guidance programme. This can be accomplished by keeping track of the needs of the parents and to update all the information regarding the slow learner. The ultimate goal will still be to create a positive working relationship between parent and teacher, to accommodate the needs of the slow learner and to cooperate in making the slow learner a successful student and eventually a successful adult.

Pour augmenter la durée de vie des réseaux de capteurs sans fil, une solution est d'améliorer l'efficacité énergétique des protocoles de communication. Le regroupement des nœuds du réseau de capteurs sans fil en cluster est l'une des meilleures méthodes. Cette thèse présente propose plusieurs améliorations en modifiant les paramètres du protocole de référence LEACH. Pour améliorer la distribution énergétique des "cluster-heads", nous proposons deux protocoles de clustering centralisés k-LEACH et sa version optimisée k-LEACH-VAR. Un algorithme distribué, appelé e-LEACH, est également proposé pour réduire l'échange d'information périodique entre les nœuds et la station de base lors de l'élection des "cluster-heads". Par ailleurs, le concept l'équilibrage énergétique est introduit dans les métriques d'élection pour éviter les surcharges des nœuds. Ensuite, nous présentons une version décentralisée de k-LEACH qui, en plus des objectifs précédents, intègre la consommation d'énergie globale du réseau. Ce protocole, appelé, k-LEACH-C2D, vise également à favoriser la scalabilité du réseau. Pour renforcer ce dernier et l'autonomie des réseaux, les deux protocoles de routage "multi-hop" probabiliste, dénotés FRSM et CB-RSM construisent des chemins élémentaires entre les "cluster-heads" et la station de base. Le protocole CB-RSM forme une hiérarchie des "cluster-heads" pendant la phase de formation des clusters, en mettant un accent sur l'auto-ordonnancement et l'auto-organisation entre les "cluster-heads" pour rendre les réseaux le plus "scalable". Ces différents protocoles reposent sur l'idée de base que les nœuds ayant l'énergie résiduelle la plus élevée et la plus faible variance de consommation de l'énergie deviennent "cluster-head". Nous constantans le rôle central de la consommation du nœud dans nos différentes propositions. Ce point fera l'objet de la dernière partie de cette thèse. Nous proposons une méthodologie pour caractériser expérimentalement la consommation d'un nœud. Les objectifs visent à mieux appréhender la consommation pour différentes séquences d'état du nœud. Enfin, nous proposons un modèle global de la consommation du nœud. / To increase the lifetime of wireless sensor networks, a solution is to improve the energy efficiency of the communication's protocol. The grouping of nodes in the wireless sensor network clustering is one of the best methods. This thesis proposes several improvements by changing the settings of the reference protocol LEACH. To improve the energy distribution of "cluster-heads", we propose two centralized clustering protocols LEACH and k-optimized version k-LEACH-VAR. A distributed algorithm, called e-LEACH, is proposed to reduce the periodic exchange of information between the nodes and the base station during the election of "cluster-heads". Moreover, the concept of energy balance is introduced in metric election to avoid overloading nodes. Then we presented a decentralized version of k-LEACH, which in addition to the previous objectives, integrates the overall energy consumption of the network. This protocol, called k-LEACH-C2D, also aims to promote the scalability of the network. To reinforce the autonomy and networks, both routing protocols "multi-hop" probability, denoted CB-RSM and FRSM build elementary paths between the "cluster-heads" and elected the base station. The protocol, CB-RSM, forms a hierarchy of "cluster-heads" during the training phase clusters, with an emphasis on self-scheduling and self-organization between "cluster-heads" to make the networks more scalable. These protocols are based on the basic idea that the nodes have the highest residual energy and lower variance of energy consumption become "cluster-head". We see the central role of consumption of the node in our proposals. This point will be the last part of this thesis. We propose a methodology to characterize experimentally the consumption of a node. The objectives are to better understand the consumption for different sequences of the node status. In the end, we propose a global model of the consumption of the node.

This study examined the leadership roles of secondary schools department heads at two government schools in Belize. Seven participants participated in the study and data regarding their perceptions of their leadership roles were collected through open-ended semi-structured interviews. Relevant sections from Belizean education documents were purposefully selected based on their relevance to the study. Documents were used to enrich the interview data. Three data analysis strategies—content analysis (Patton, 2002), inductive analysis (Hatch, 2002), and educational criticism (Eisner, 1998)—were used in the study. Discussion of the analysis was based on the following three themes: (a) build instructional capacity, (b) increase learning opportunities for students, and (c) provide technical and vocational teachers access to professional training and development in technical and vocational education. The themes are perspectives from which to view and understand the leadership roles of secondary school department heads at two government schools in Belize. Three major conclusions resulted from this study. One, secondary school department heads at the two government schools in Belize are school leaders whose multifaceted role includes myriad duties, responsibilities, and obligations. Two, department heads are street-level bureaucrats who implement and enforce policies and regulations through their classroom routines and the decisions they make. Three, policymakers, school management, and department heads need to invest in sustained professional training and development activities that are specifically designed for department heads. Implications for policy and practice include the need to establish minimum professional selection criteria for the role of department heads, expand the capacity of teacher training institutions, and foster a culture that supports and nurtures shared instructional leadership and learning among department heads.

The objective of this master thesis is to design a robotic work cell for automated insertion of thermostatic heads. The proposed design was based on the comprehensive analysis of the current workplace. By taking the demands of the company and customer into consideration, several possibilities of the robotic work cell design were proposed, from which the most suitable one was chosen and carefully elaborated. During the process of designing, several safety standards had to be taken into consideration in order to mitigate risks. For that purpose, a risk analysis was conducted as well. Using the Siemens Process Simulate software, the proposed robotic work cell concept was verified, including cycle time analysis. The last part of the thesis is an assessment of the initial expenditures of the robotic work cell equipment, as well as the return of the investment calculation. Drawing of the robotic work cell layout is attached to the thesis.

En los últimos años, los padres de familia han tomado mayor importancia a la inversión en educación que brindan a sus hijos, y estos a menudo deciden gastar en la educación de sus hijos tomando en cuenta factores que pueden influir en esta decisión. Es por ello, que el presente trabajo analiza la variación del gasto en educación que realizan los jefes de familia en sus hijos, con respeto a factores, como: la educación que tiene los padres de familia, el género de los hijos, los ingresos de los jefes de familia, el tamaño de la familia con respecto al número de hijos y la diferencia que habría si el jefe de familia es mujer. Se recurrió a una metodología Tobit. Los resultados muestran la existencia de influencia de los factores mencionados anteriormente para los años 2013, 2016 y 2019 en el Peru. Además, se puede visualizar que, la diferencia en inversión de los padres de familia, según sector, es decir, urbano y rural, ya no es una variable significativa en los últimos años. / In recent years, parents have placed greater importance on investing in education they provide to their children, and many times they decide to spend on their children's education considering factors that can influence this decision. That is why the present work analyzes the variation in spending on education by heads of family on their children, with respect to factors such as: parents' education, gender of children, income of heads of family, the size of the family with respect to the number of children and the difference it would have if the head of the family were a woman. A Tobit methodology was used, as mentioned above, this model will consider the characteristics of the heads of household and children, as well as demographic characteristics. It is found that the probabilities that a head of the family invest in the education of their children increase according to the level of studies they reach, in addition to a measure that generates income, the probability of spending will be greater. The results show the existence of influence of the aforementioned factors for the years 2013, 2016 and 2019 in Peru. The results mention that in Peru the educational inequality with respect to the gender of the students has a very short gap. Furthermore, it can be observed that, in Peru, the difference in parental investment, by sector, that is, urban and rural, is no longer a significant variable in recent years. / Trabajo de investigación

There has been a huge surge in the Internet of Things (IoT) applications in recent years. The sensor nodes in the IoT network generate data continuously that directly affects the longevity of the network. Even though the potential of IoT applications are immense, there are numerous challenges like security, privacy, load balancing, storage, heterogeneity of devices, and energy optimization that have to be addressed. Of those, the energy utilization of the network is of importance and has to be optimized. Several factors like residual energy, temperature, the load of Cluster Head (CH), number of alive nodes, and cost function affect the energy consumption of sensor nodes. In this paper, a hybrid Whale Optimization Algorithm-Moth Flame Optimization (MFO) is designed to select optimal CH, which in turn optimizes the aforementioned factors. The performance of the proposed work is then evaluated with existing algorithms with respect to the energy-specific factors. The results obtained prove that the proposed method outperforms existing approaches.

La presenten investigación busca determinar el efecto del nivel educativo de los jefes del hogar sobre la seguridad alimentaria de los hogares peruanos. El análisis se realiza a través del modelo Tobit con el fin de evidenciar cuales son los factores y en que cantidad; es decir, busca determinar si el impacto del nivel educativo de los padres es positivo o negativo, junto a otros determinantes dentro del hogar, y cuánta es la probabilidad de ocurrencia de que un hogar cuente con seguridad alimentaria. La investigación concluye que un hogar cuente con seguridad alimentaria, medida como el gasto alimentario del hogar, si los jefes del hogar tienen un nivel educativo más alto junto con mayores ingresos. / This research project aims to determine the effect of the educational level of household heads on the food security of Peruvian households. The analysis is carried out through the TOBIT model in order to show which are the factors and in what quantity. That is, aims to determine whether the impact of the parent’s educational level is positive or negative, together with other determinants within the household has food security. The research concludes that a household has food security, measured as the household’s food expenditure, if the heads of the household have a higher educational level along with higher income. / Trabajo de investigación

This investigation compared the perceptions of responsibility, authority, and delegation held by department chairpersons and those held by faculty members in Saudi Arabian universities. The three purposes of the study were to determine differences in perceptions between department chairpersons and their faculty members, to determine any significant interaction between the independent variable (position) and each of the eleven clarification variables with respect to respondents' perceptions, and to determine any significant difference in perceptions between respondents in different categories of each of the clarification variables. The findings were as follows. There was a significant difference in perceptions of responsibility between department chairpersons and their faculty members, but no such difference was found for authority or delegation. Significant interactions were found between position and three of the clarification variables with regard to perceptions of responsibility, between position and none of the clarification variables with regard to perceptions of authority, and between position and four of the clarification variables with regard to perceptions of delegation. In addition, significant differences in perceptions were found among categories of six clarification variables with regard to responsibility, of four clarification variables with regard to authority, and of seven clarification variables with regard to delegation.

Inom tillverkning är skärande bearbetning en vanligt förekommande process och däribland borrning.Verktygskostnader har stor påverkan på den totala tillverkningskostnaden då till exempel ett heltarbetsstycke i värsta fall kan gå förlorat vid verktygshaveri. Genom sitt arbete med ständigaförbättringar håller Scania sig konkurrenskraftiga med sina produkter av hög kvalitet. I dettaexamensarbete inom masterprogrammet Industriell Produktion på KTH har en specifik typ av borrmed löstagbar borrkrona utvärderats med avsikt att undersöka nya fabrikat.Uppdragsgivaren var motorbearbetningen (DM) på Scania i Södertälje. Arbetet inleddes med attinförskaffa relevant kunskap gällande verktyget som undersöktes. Samtidigt utfördes ennulägesanalys där de använda borrarna på DM kartlades tillsammans med information kring pris,livslängd, m.m. Utifrån kartläggingen sammanställdes statistik som analyserades för att identifierahur stor påverkan en eventuell standardisering skulle kunna ha.Utvärderingen av borrar bestod av praktiska experiment där sju olika verktyg med en diameter på12,2 mm testades under samma förhållanden. Testet utformades i enighet med berörda parter påDM samt efter studier av adekvat litteratur rörande borrexperiment. Fyra parametrar testadesutöver borrarnas livslängd. Dessa var axialkraft, förslitning, håldiameter och spånor. Parametrarnaämnades jämföras och analyseras för att dra slutsatser kring borrarnas prestationer.Nulägesanalysen visade att ett fabrikat utgjorde hela 69% av borrarna på hela DM. Efter slutfördaborrtester hade enbart tre av sju genomfört utan haveri, Borr E, F och G. Samtliga sju borrar visadegodkända spånor och höll sig inom toleranserna för angiven håldiameter. Axialkrafterna varierademellan borrarna där Borr F hade lägst krafter och Borr A högst. Borr E visade bäst motstånd motförslitningar. Utifrån detta valdes borrarna E, F och G att rekommenderas för deras goda prestationermed Borr E på första plats. Utöver det föreslogs att utbudet av fabrikat som kan användas på DMbegränsas för att uppnå kostnadsbesparingar gällande verktygen. / Drilling is a common cutting process within manufacturing. Tool costs have great influence on thetotal manufacturing cost since a tool break down can cause an entire work piece to be scrapped.Through their constant work with improvements, Scania stays competitive with their high qualityproducts. This Master Thesis in Industrial Production and Management at KTH has evaluated aspecific type of drill with indexable heads with the purpose of investigating new brands.The Engine Manufacturing department (DM) at Scania in Södertälje requested this project. The taskwas initiated by obtaining knowledge about the tool that were to be investigated. Simultaneously ananalysis of the current state was performed where the drills at DM were mapped out withinformation regarding price, tool life, etc. The statistics were compiled and analysed to identify theeffect of an eventual standardisation.The evaluation consisted of practical experiments where seven different drills with a diameter of12,2 mm was tested under the same circumstances. The test was design in concurrence with affectedparts at DM and studies of adequate literature regarding drilling experiments. Four parameters weretested in addition to the tool life of the drills. These were axial force, tool wear, hole diameter andchips. The parameters were intended to be used for comparing and analysing in order to makeconclusions regarding the performance of the drills.The current state analysis showed that one brand represented 69% of the drills used at DM. Afterfinished drilling tests three out of seven drills managed to complete the test without tool breakdown. All drills produced chips that were acceptable and the measured diameters stayed within thegiven tolerances. The axial forces varied between the drill where Borr F had the lowest force and BorrA the highest. Borr E showed the best resistance against tool wear. From the results the drills thatwere recommended were Borr E, F and G because of their good performances with Borr E in the firstplace. Ultimately it was suggested to limit the amount of brands used at DM to achieve cost savingsregarding the tools.

Total hip joint prostheses made of CoCrMo heads versus ultra high molecular weight polyethylene (UHMWPE) cups have a limited lifetime, mainly due to the wear of the UHMWPE cups as a result of high friction between the articulating surfaces leading to osteolysis and implant loosening with revision surgery becoming inevitable in more active patients. Tribology plays an important role in developing the design, minimizing wear and reducing friction of hip joint prostheses in order to improve their long-term performance, with good lubricating properties. Metal-on-metal hip resurfacing prostheses have shown significantly lower wear rates compared with conventional metal-on-polyethylene implants and thus osteolysis is potentially reduced leading to increased lifetime of the prosthesis. Nevertheless, excessive wear of metal-on-metal joints leads to metal ion release, causing pseudo-tumours and osteolysis. An alternative approach to such bearings is the use of newly developed carbon fiber-reinforced poly-ether-ether-ketone (CFR PEEK) acetabular cups articulating against ceramic femoral heads due to their better wear resistance compared to UHMWPE. In this study, therefore, friction and lubrication properties of large diameter, as cast, Co-Cr-Mo metal-on-metal hip resurfacing implants with various diameters and clearances have been investigated and compared to those of the newly developed zirconia toughened alumina (ZTA) ceramic femoral heads articulating against carbon fiber reinforced poly-ether-ether-ketone (CFR PEEK) acetabular cups with different diameters and clearances. Friction hip simulator was used to measure frictional torque and then friction factors were calculated along with Sommerfeld numbers leading to Stribeck analysis and hence the lubricating mode was also investigated. This involved using lubricants based on pure bovine serum (BS) and diluted bovine serum (25 vol. %BS+75 vol. %distilled water) with and without carboxymethyl cellulose (CMC) (as gelling agent). Standard Rheometer was used to measure lubricant viscosity ranged from 0.0014 to 0.236 Pas at a shear rate of 3000 . Pure bovine serum, diluted bovine serum without CMC and with CMC (25BS+75DW+0.5gCMC and +1gCMC) showed pseudoplastic flow behaviour up to shear rate of ¿139 above which a Newtonian flow with significant increase in shear stress was observed. The viscosity flow curves for the 25BS+75DW+2gCMC, +3.5gCMC and +5gCMC showed only shear thinning up to a shear rate of 3000 . The shear rate application modified the flow behaviour of bovine serum from a pseudoplastic to a Newtonian flow depending on its purity and CMC content. This will cause a different frictional behaviour depending on joint diameter and clearance, as seen in this work. The experimental data were compared with theoretical iv predictions of the lubricating regimes by calculating theoretical film thickness and lambda ratio. The metal-on-metal Biomet ReCaps showed similar trends of Stribeck curves, i.e. friction factors decreased from ~0.12 to ~0.05 as Sommerfeld numbers increased in the range of viscosities ~0.001-0.04Pas indicating mixed lubrication regimes above which the friction factor increased to ~0.13 at a viscosity of 0.236Pas. The Stribeck analyses suggested mixed lubrication as the dominant mode with the lowest friction factor in the range ~0.09 - ~0.05 at the physiological viscosities of ~0.01 to ~0.04 Pas and that such joints can be used for more active patients as compared to the conventional total hip replacement joints with 28mm diameter. The Stribeck curves for all ZTA ceramic-on-CFR PEEK components illustrated a similar trend with BS fluids showing higher friction factors (in the range 0.22-0.13) than the diluted BS+CMC fluids (in the range 0.24-0.05). The friction tests revealed boundary-mixed lubrication regimes for the ZTA ceramic-on-CFR-PEEK joints. The results, so far, are promising and suggest clearly that the newly developed ZTA ceramic femoral heads articulating against CFR PEEK cups have similar friction and lubrication behaviour at optimum clearances to those of currently used metal-onmetal hip resurfacing implants at the range of viscosities 0.00612 to 0.155Pas. These results clearly suggest that the ZTA ceramic-on-CFR-PEEK joints showed low friction at the physiological viscosities of ~0.01Pas in the range ~0.1-0.05, suggesting that these novel joints may be used as an alternative material choice for the reduction of osteolysis. The result of this investigation has suggested that the optimum clearance for the 52mm diameter MOM Biomet ReCaps could be ~170¿m. However, 48 and 54mm joints showed lower friction due to clearances to be >200¿m. For the 52mm ZTA ceramic-on-CFR-PEEK joints the optimum clearance seems to be ¿ 630¿m radial clearance. These results suggested that increased clearance bearings have the potential to generate low friction and hence no risk of micro- or even macro-motion for the ceramic-on-CFR-PEEK joints. This study found no correlation between theoretical predictions and experimental data for all metal-onmetal and ZTA ceramic-on-CFR PEEK bearings at the physiological viscosity (0.0127Pas). However, at lubricant viscosity of 0.00157Pas, the theoretical prediction of lubrication regime correlated well with the experimental data, both illustrating boundary lubrication. As expected, a decrease in viscosity resulted decrease in the film thickness.