Showing papers in "International Journal of Embedded Systems in 2015"
TL;DR: A novel method to analyse the time-activity pattern by utilising mobile web usage log is proposed and it is shown that this method achieves an acceptable performance, and can truly measure the time -activity pattern of human beings.
Abstract: Air pollution has become a striking problem in recent years. When estimating the degree of human exposure to a particular air pollutant, time-activity pattern is one of the most important factors, which is able to quantify the time people spend in different micro-environments, such as indoor and outdoor. Traditional surveys use the method of questionnaires and telephone calls to explore the time-activity pattern. In this paper, we propose a novel method to analyse the time-activity pattern by utilising mobile web usage log. We test the method on two datasets covering about four million users. Experiments show that our method achieves an acceptable performance, and can truly measure the time-activity pattern of human beings.
23 citations
Journal Article•
TL;DR: The result indicated the negative emotion with lower arousal can improve the tendency of risk taking, which confirms emotional maintenance hypothesis in psychological discipline.
Abstract: Previous psychological researches prove that emotion is of importance in individual risk decision making. So could the public emotion (social moods) influence the collective risk decision making such as the stock market? We obtained the five basic social moods including happiness, sadness, fear, anger and disgust by analysing the text content of daily Sina Weibo using our emotion lexicon. Then we investigated the correlation between the daily social moods and Shanghai Composite Index volume by means of Granger causality analysis and linear regression model. We found sadness can significantly improve the predictive accuracy of the trading volume by 2.4% and reduce the MAPE by 8. The analyses for the five social moods indicated the arousal of sadness is the lowest, and the lowest 25% terms of sadness can predict the total trading amounts of SSEC too. The result indicated the negative emotion with lower arousal can improve the tendency of risk taking, which confirms emotional maintenance hypothesis in psychological discipline.
22 citations
TL;DR: An overview of mobile big data's content, scope, methods, challenges and samples is presented and a mobile data infrastructure (MDI) and aMobile data lifetime management (MDLM) model is introduced.
Abstract: Big data is the buzzword of the year. Especially in the field of telecommunications, telecom operators have been put to the test of mobile big data because it has huge, varied and complex structure with challenges to store and analysis. However, big data also has potential big value. Revealing hidden information and making further processes in mobile big data, telecom operators could depict user behaviour to improve average–revenue–per–user (ARPU) and detect real–time device information to prevent potential equipment failure. An overview of mobile big data's content, scope, methods, challenges and samples is presented in this paper. The paper also discusses the current process and analysis on mobile big data and introduces a mobile data infrastructure (MDI) and a mobile data lifetime management (MDLM) model. Finally, a mobile big data system will be described.
19 citations
TL;DR: In this paper, the authors investigated the factors that influence effective teaching of chemistry in the secondary schools in Buffalo City Metropolitan Municipality, Eastern Cape Province of South Africa, and the relationship between the students and teachers responses to these factors was critically examined.
Abstract: KEYWORDS Incompetent Teachers. Inadequate Infrastructures. Poor Motivation. Laboratory. Chemistry Teachers ABSTRACT The present study sought to investigate the factors that influence effective teaching of chemistry in the secondary schools in Buffalo City Metropolitan Municipality, Eastern Cape Province of South Africa. The relationship between the students and teachers responses to these factors was critically examined. The instrument used for data collection is a structured questionnaire developed from the literature review. It contained 30 items, where 15 items were for the students and the other 15 items were for the teachers. The instrument used the 4-point Likert format of strongly agree, agree, strongly disagree, disagree and were administered to one hundred and twenty individuals comprising both students and teachers. The data was collected and analyzed using chi-square statistical tool. The result showed that there is no significance relationship in the responses of students and teachers to some of the factors considered. However, some suggestions were offered on how the management of the schools, government and students involved could be improved on the factors highlighted to make the teaching and learning of chemistry more effective and interesting.
19 citations
TL;DR: The results show that an IoT sensor network using the proposed architecture can be easily deployed as a software update and the use of UHE does not significantly increase the monetary cost of any single sensor node.
Abstract: Internet of things (IoT) is a powerful platform for healthcare monitoring for chronic diseases as a result of fairly inexpensive, secure, reliable sensors that do not require a complicated deployment process. In this paper we present a novel shared–node IoT network architecture that can be used to reduce the monetary cost of deploying proof of concept IoT sensor networks using non–ubiquitous technologies. The proposed architecture shares the services of some sensor nodes in the network between multiple users to reduce the monetary cost. We found that IoT networks can be vulnerable to spoofing and data loss; to reduce the probability of these attacks from succeeding, the proposed IoT architecture utilises a ubiquitous homomorphic encryption (UHE) to intrinsically validate the nodes, users, and the data. We use the NS3 simulation platform to validate the proposed architecture. The results show that an IoT sensor network using the proposed architecture can be easily deployed as a software update and the use of UHE does not significantly increase the monetary cost of any single sensor node.
16 citations
TL;DR: Perceptions of educators and parents about the involvement of the latter in the process of implementation of the National School Nutrition Programme in the Sedibeng and Fezile Dabi school districts in the Gauteng and Free State provinces indicated that the procedure for recruitment of parents was not clear and there were no clear strategies in place to empower parents.
Abstract: This paper reports on perceptions of educators and parents about the involvement of the latter in the process of implementation of the National School Nutrition Programme in the Sedibeng and Fezile Dabi school districts in the Gauteng and Free State provinces. The paper elaborates on the empirical data gathered by means of qualitative and explorative approaches using interviews. The results indicated that the procedure for recruitment of parents was not clear resulting in lack of transparency in the process. Furthermore, there were no clear strategies in place to empower parents thus, parents could not initiate and take ownership of the programme. Stipulations of the policy regarding their roles are limiting to the extent that they could not hold suppliers accountable for their inefficiency. Volunteering as food handlers was an eye-opener to some parents enabling them to realise the importance of their involvement in their children's education in general.
15 citations
TL;DR: It is concluded that teachers have positive perceptions of their professional development even though they are not being supported adequately by Department of Basic Education and their schools.
Abstract: The aim of this study was to investigate teachers' perceptions of the impact of Continuing Professional Development on promoting quality teaching and learning. This study adopted a mixed method approach using both quantitative and qualitative research designs. Closed-ended self-administered questionnaires and interview schedule were used to collect data. Two hundred teachers were sampled through simple random sampling procedure to complete the questionnaires, while ten teachers participated in face-to-face semi-structured interviews. The results show that teachers recognise the impact of professional development in broadening their pedagogical and content knowledge, teaching skills and strategies to improve student's learning. Results also show that teachers are undergoing professional development initiatives in order to gain financial rewards. The study concludes that teachers have positive perceptions of their professional development even though they are not being supported adequately by Department of Basic Education and their schools.The study recommends that adequate financial rewards be put in place to encourage and motivate teachers when furthering their studies as part of Continuing Professional Development. Further research into the factors influencing teachers furthering their studies as part of professional development in South Africa should be undertaken.
15 citations
TL;DR: In South Africa, discipline problems seem to exist in South African schools and the situation is getting worse and even out of hand, including bullying behavior as mentioned in this paper, and traditional behavior management practices, including...
Abstract: Discipline problems seem to exist in South African schools and the situation is getting worse and even out of hand, including bullying behavior. Traditional behavior management practices, including...
13 citations
TL;DR: In this paper, an investigation of ineffective communication among educators' teaching performance in Fezile-Dabi District, Free State Province, South Africa was conducted. The study utilized a qualitativ...
Abstract: This paper reports on an investigation of ineffective communication among educators’ teaching performance in Fezile-Dabi District, Free State Province, South Africa. The study utilized a qualitativ...
12 citations
TL;DR: The presented results form a first step for the future to be able to guarantee the requested product quality over its lifetime, but nevertheless other methods of analysis have to be qualified for the determination of the aging behavior of SLS parts.
Abstract: The key in selective laser sintering (SLS) of polyamide 12 for exceeding the cusp from a prototyping to a serial production technique poses the long-term behavior of such components. The improvement of additive manufacturing technologies is attended by the enlargement of the possible ranges of use. The crucial obstacle for their actual use is the ignorance of the long-term properties and the consequential fact of not given warranty. The aging behavior of polyamide 12 based injection molded parts and powder for the SLS process is largely probed and methods of analysis are well-established. On the basis of several build jobs consisting of vertically build tensile bars, oven storage experiments are realized. Storing for several time periods and temperatures allows a first calculation of the aging behavior in consideration of the building position and process parameters of each bar. First of all the adaptability of two methods of analysis, tensile test und solution viscosimetry, for determining the state of the aging of SLS parts is surveyed. It shows that depending on the used method of analysis the building position of the picked up sample could play a role. Furthermore the influence of the process parameters, the aging processes itself and the necessary storage conditions for the artificial aging of the parts are considered. All in all this article gives a review of the aging mechanisms of oven stored polyamide 12 parts, possible methods of analysis to determinate their state of aging and first results to qualify the adaptability to selective laser sintered parts. In Addition to that a first correlation between mechanical and chemical properties is made. The presented results form a first step for the future to be able to guarantee the requested product quality over its lifetime, but nevertheless other methods of analysis have to be qualified for the determination of the aging behavior of SLS parts.
12 citations
TL;DR: A dynamic scheduling algorithm is presented that adopts preemption control technique and dynamic mandatory/optional partitioning strategy to reduce the energy consumption of the whole system dynamically and effectively minimise the system–wide energy consumption.
Abstract: In this paper, we study the problem of reducing the energy consumption for a weakly hard real–time system. The weakly hard real–time system is modelled by the (m, k)–constraints, which require that at least m out of any k consecutive jobs of a task meet their deadlines. Since the system energy is consumed not only by the processor alone but also in a large part by other peripheral devices, we first propose a static approach, with the specifications of peripheral devices taken into consideration, to partition the jobs into mandatory/optional jobs to achieve the dual goals of (m, k)–guarantee and overall energy minimisation. Based on that, we present a dynamic scheduling algorithm that adopts preemption control technique and dynamic mandatory/optional partitioning strategy to reduce the energy consumption of the whole system dynamically. Our approach can effectively minimise the system–wide energy consumption and guarantee the (m, k)–deadlines at the same time. The novelty and effectiveness of our techniques are demonstrated through extensive simulation studies.
TL;DR: Feedback indicated that ECE was perceived positively by students and could provide a framework for integration of basic sciences with clinical subjects for the medical students.
Abstract: In the present setup, the traditional discipline- based curriculum with clinical exposure during the second year of study is being followed. However, the students found it difficult to recall important basic concepts during their clinical postings. One of the methods to improve the quality and usefulness of the basic sciences taught to medical students is early clinical exposure (ECE). Hence, the present observational study was carried out among 150 first MBBS students to sensitize them for a clinical set-up, to appreciate the finer aspect of human behavior while dealing with patients and motivate them to develop further interest in first year subjects. They were exposed to clinical wards in small group. A prevalidated questionnaire was administered to the students after clinical ward rounds. Feedback indicated that ECE was perceived positively by students and could provide a framework for integration of basic sciences with clinical subjects for the medical students.
TL;DR: The study identified some negative factors that are affecting the students’ academic performance in one school at a historically disadvantaged South African university and concluded that steps should be taken to remedy the situation.
Abstract: The improvement of throughput, graduation and retention rates in South African higher education is a national priority. Student academic performance data in one school at a historically disadvantag...
Journal Article•
TL;DR: This paper aims to coordinate trust and security, and proposes a trust-based cloud security framework, called trustworthy computing framework (TwCF), for TTS, and identifies the key elements and emerging research issues in TwCF.
Abstract: The concept of tailored trustworthy spaces (TTSs) has been proposed to build a trustworthy cyberspace and solve the trust and security issues in clouds. However, the problem of building a trustworthy cloud infrastructure to support TTS has not been addressed yet. In this paper, we aim to coordinate trust and security, and propose a trust-based cloud security framework, called trustworthy computing framework (TwCF), for TTS. In this framework, the application-aware policy is adopted to suit the users' security contents. A trust management framework is designed to manage trust, security and policies, and fulfil the trust negotiation and decision-making in TTS. The platform security mechanisms concerning the key elements in cloud security are designed to assure the deployment of security policies. In this paper, the key elements and emerging research issues in TwCF are identified and a case study of establishing a TTS in platform as a service (PaaS) is presented.
TL;DR: A DOE approach using the response surface methodology was utilized to study the correlations between process parameters and part properties and optimized process parameter sets are established for PA 11 resulting in improved part properties.
Abstract: Due to the advancements during the last decade, the laser sintering process has achieved a high technical level, allowing for Rapid Manufacturing of parts in some applications. However, only few polymers are commercially available for the process. Polyamide 12 dominates the market with share of nearly 90 %. Other laser sintering materials differ in part properties from PA 12. Therefore, they are more suitable for some specific applications. Within these, Polyamide 11 has the highest distribution on the market. PA 11 offers some advantages like significant higher part ductility but also some disadvantages like more warpage or higher processing temperatures. However, literature provides in general only little information on the processing of PA 11 and how to achieve optimal processing conditions. A DOE approach using the response surface methodology was utilized to study the correlations between process parameters and part properties. Laser power, scan speed, hatch distance, layer thickness and outline energy density were varied in order to improve the part quality considering mechanical properties, surface roughness and part density. Additionally, results for process influences and part properties were compared with those found for Polyamide 12 in order to derive general correlations. Based on the performed study, optimized process parameter sets are established for PA 11 resulting in improved part properties.
TL;DR: The study examines challenges encountered by pre-service teachers during teaching practice and concludes that a conducive environment, exploration of experiential knowledge, student centeredness, and teaching language as a social practice are the fundamental teaching philosophies.
Abstract: Teaching practice provides student teachers with the chance to express their personal educational philosophies, theories and understandings and creates an opportunity for student teachers to experi...
TL;DR: In this paper, the challenges teachers encounter in identifying learners with learning barriers in two primary schools in the East London district, South Africa were investigated and the authors focused on diversity an...
Abstract: This study investigates the challenges teachers encounter in identifying learners with learning barriers in two primary schools in the East London district, South Africa. It focuses on diversity an...
TL;DR: In this paper, a principal of a dysfunctional school used a people-centred approach that emphasised morals, ethics and values to bolster the school's effectiveness and encouraged building of character through values among teachers.
Abstract: School principals today face a number of challenges in their schools. More often, they need to try various strategies to improve the performance in their schools. While many critics can argue for the bringing back of morality and ethics in "messy work places", others do not concur. Yet, effective principals learn to lead with their staff members. Moreover, it is also crucial for staff members to be involved in bringing about solutions, for this helps them learn that they can address some of their challenges. In this case study a principal of a dysfunctional school used a people-centred approach that emphasised morals, ethics and values to bolster the school's effectiveness. Using ubuntu philosophy, the principal encouraged building of character through values among her teachers. The study showed that school leaders should not overlook working with the people as they create a community of leaders.
TL;DR: A preliminary methodology for PA12 powder sintering is proposed to provide a better understanding of the properties of the material, and more efficient use of the selective laser melting material.
Abstract: Selective Laser Melting is an additive manufacturing technique, using a laser to promote the fusion followed by the solidification of a powder bed into a component. One of the most interesting topics about this process is the coalescence behavior of particles taking place in the powder bed during exposure. The coalescence of particles has been investigated in different fields of materials. Polyamide 12 (PA12) is a polymer material which is usually used in the selective laser melting process. Therefore, the characterization of the sintering behavior of PA12 powder plays an important role to improve the performance of the material and the process.
The purpose of this study is to investigate the sintering process of PA12. The main goals are: to calculate the neck growth during isothermal sintering process based on the modified Frenkel´s model; and to compare the sintering model with results from microscopic observation of PA12 powder in the hot stage. Important parameters for the sintering model such as temperature-sensitive viscosity and surface tension are measured in this paper. Furthermore, the effects of heating rate and sintering temperature on the neck growth were investigated by the microscopic observation of molten particles in the hot stage. The modeling showed a reasonable agreement with the microscopic observation in the hot stage. Specially, the effect of the heating rate on the sintering temperature was studied. It was confirmed that the sintering behavior of PA12 powder started at a higher temperature with increasing heating rate. Based on the findings from this study, a preliminary methodology for PA12 powder sintering is proposed. It provides a better understanding of the properties of the material, and more efficient use of the selective laser melting material.
TL;DR: In this paper, the authors explore the perceptions of women in leadership in higher education about the need for the development of institutional structures to support them in leadership positions using the paradigm of the feminist standpoint theory.
Abstract: Using the paradigm of the feminist standpoint theory, this paper explores the perceptions of women in leadership in Higher Education about the need for the development of institutional structures to support them in leadership positions. Three open-ended questions were sent via e-mail to the respondents, who were purposefully selected as a convenient sample. The responses were analysed using a qualitative research design of thematic analysis. Provide research methodology. These findings provide recommendations with regard to the strategies proposed by women in leadership positions as to the ways in which Higher Education institutions may 'feather the nest' for women in leadership positions.
TL;DR: The findings suggested an exposure of the student teachers to a learning environment in which they can contextualise the theoretical knowledge they gathered during their training, and recommends that students should have a multiple pre-service training before they complete the program.
Abstract: An integral component of teacher education, training and preparation is teaching practice. It affords student teachers experience in the actual teaching and learning environment. The major ...
TL;DR: The main findings indicate that flexible access via different devices was the most valued feature of this resource and the possibility of experimenting and simulating by means of controlling the main parameter of the model was also found to be particularly useful.
Abstract: This paper describes the application of an online interactive simulator of discrete-time Markov chains to an automobile insurance model. Based on the D3.js library, an interactive visual animation depicts the dynamics of individual policyholders in a bonus-malus system of automobile insurance. A survey was conducted among MSc students who used the simulator to obtain a preliminary assessment of the perceived usefulness in several dimensions of their learning process. The main findings indicate that flexible access via different devices was the most valued feature of this resource. In addition, the possibility of experimenting and simulating by means of controlling the main parameter of the model was also found to be particularly useful.
TL;DR: In this article, the authors examined the effects of problem-based learning strategies and gender on students' academic achievement and found that Problem Based Learning Strategies are more effective than conventional methods in algebra.
Abstract: This study examined the effects of problem based learning strategies and gender on students' academic achievement. A 3X2 pre-test and post-test control group quasi-experimental group design was adopted in the study. The instruments constructed and used for the study were: Problem Based Learning Strategies which are in two parts (PBLSa), (PBLSb) and Conventional Teaching Guide (C.T.G). Two hypotheses were generated and tested in the study at 0.05 alpha levels. One of the major findings of this study was that (PBLSa) and (PBLSb) are more effective than conventional method in students' academic achievement in algebra (x= 3.05; SE =.720), (= 4.23; SE=.714), (= 3.36; SE =.726) in that order. The study also revealed there is no significant main effect of gender on students' academic achievement, female(= 15.63) and male (= 15.41). However, the study recommended that problem- based learning strategies should be embraced by both the teachers and learners in order to enhance students' academic achievement in algebra.
TL;DR: In this paper, the authors argue that models for professional development of teachers that advocate for the promotion of effective teaching and learning have not been successful in improving the quality of teaching in public secondary schools.
Abstract: Models for professional development of teachers that advocate for the promotion of effective teaching and learning have not been successful in improving the quality of teaching in public secondary ...
TL;DR: The use of ICT in lifelong learning is viewed in relation to different settings of learning i.e. formal, informal and non-formal learning, with special reference to the third-age.
Abstract: The purpose of this paper is to present a review of sample papers that have been published from 2003-2013 regarding lifelong learning and ICT. The use of ICT in lifelong learning is viewed in relation to different settings of learning i.e. formal, informal and non-formal learning, with special reference to the third-age. A special focus is also given on the technologies and specific tools which are used for the provision of lifelong learning. The role of ICT networks, web technologies in e-learning, mobile learning tools and virtual worlds as facilitators of knowledge sharing in all types of learning settings is examined.
TL;DR: In this article, the influence of teachers' learning styles on their classroom teaching and learning practices was examined in various school districts in a mixed-method study conducted in two different states.
Abstract: This paper examines the influence of teachers’ learning styles on their classroom teaching and learning practices. The reported mixed method study was conducted in various school districts in a lar...
TL;DR: Sosibo, Z., and Katiya, M., this paper closed the loop between access and success: early identification of at-risk students and monitoring as key strategies used by a South African University.
Abstract: Sosibo, Z.; and Katiya, M.; (2015). Closing the Loop between Access and Success: Early Identification of At-risk Students and Monitoring as Key Strategies Used by a South African University. International Journal of Educational Sciences 01/2015; 8(2):271-279.
TL;DR: In this paper, the incorporation of social media in pedagogic revolution and innovation via technology in higher education institutions, specifically, incorporation of Twitter and Facebook, has been explored and analyzed.
Abstract: Research has been abundant in generating studies on pedagogical revolution and innovation via technology in higher education institutions, specifically the incorporation of social media in pedagogi...
Journal Article•
TL;DR: A multilayer collaborative traceback technique based on net-flow fingerprint that improves the efficiency of suspicious path extraction and reduces local overload of traceback servers without compromising the accuracy of trace back.
Abstract: Aimed at loop fallacy, indeterminate serialisation of suspicious nodes and local overload problems of suspicious information source traceback in net-flow exchange, this paper proposes a multilayer collaborative traceback technique based on net-flow fingerprint. The traceback is divided into controllable inter-AS layer, intra-AS routing layer and controllable subnet layer. Based on the characteristics of each layer, it achieves efficient suspicious path extraction in controllable inter-AS layer by BGP protocol properties. In intra-AS routing layer, it solves loop fallacy by directed graph transformation and indeterminate serialisation of suspicious nodes by local time relationship approach. In controllable subnet layer, it achieves precise location by using forwarding tables. What is more, by proposing multilayer collaborative approach, it improves the efficiency of suspicious path extraction and reduces local overload of traceback servers without compromising the accuracy of traceback. Finally, the correctness and computational complexity of NFCMT are proved, and the feasibility and correctness of this scheme are discussed by experiments.
TL;DR: It was concluded that mothers waiting at the gate for their pregnant teenagers are psychologically, socially and economically affected.
Abstract: Teenage pregnancy is a global problem in both developed and underdeveloped countries. This is evidenced by the high rates of pregnant teenagers in South African schools. The study sought to explore the perceived challenges faced by mothers of pregnant teenagers who are attending a particular schools Mopani district. A qualitative explorative and descriptive approach was used. The population comprised of all mothers of pregnant teenagers who were waiting at the school gate. A non-probability, convenient sampling method was used to sample 11 participants. In-depth individual interview guided by one central question directed the interview which was: "what challenges do you experience as you are expected to wait at the school gate for your pregnant teenager?" Open coding method was used to analyse the data. Three themes emerged namely: Socio-economic implications to parents; Emotional implications to parents and to the pregnant learner. The study recommended that school should be provided with basics medical equipments to use should there be a need for delivery at the school. Teachers should be empowered on conduction of emergency delivery. Ethical and trustworthiness were ensured. It was concluded that mothers waiting at the gate for their pregnant teenagers are psychologically, socially and economically affected.