Teacher professional learning for technology integration in mathematics classrooms through online learning communities : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Information Technology at Massey University, Albany, New Zealand

The new school curricula in Indonesia emphasise the integration of technology into instructional practices. The infusion of technology in mathematics education requires teachers to align their teaching practices with ongoing technological innovations. Integrating technology into mathematics classrooms requires teachers to have a good knowledge of mathematics content, technology and pedagogy. Teachers also need to consider their school environments. Existing teacher professional development programmes are seen to be failing to meet teacher needs regarding content delivery that sometimes does not match the existing school conditions. The premise underlying this research is that the use of an online learning community (OLC) may present a possible solution to the current challenges. Thus, the intention of this study was to investigate the potential of OLCs to help develop teachers’ learning to fulfil their professional needs in integrating technology with the teaching of mathematics. An ethnographic approach was used to investigate the phenomenon of teacher learning within an OLC and the implementation of the new knowledge acquired in their mathematics teaching practices. Empirical data from five case studies were used to examine how participation in the OLC affected teaching practices for five teachers. The results revealed that teacher participation in an OLC offered opportunities and challenges. Teachers de-privatized their practices as they actively engaged in social learning interactions to share knowledge and help each other with the appropriate use of technology in teaching mathematics. Teachers also faced some challenges, which impeded them. These challenges included differences in school policies, such as restrictions on using social media and limited technical infrastructure, which hindered teachers from fully leveraging the OLC. Teachers with less experience in teaching with technology and with low levels of technology skills tended to be passive in the OLC. Cultural contexts revealed that lack of experience and caution about expressing opinions made teachers feel ewuh pakewuh, a shyness in openly expressing their thoughts. Despite these barriers, the study provided evidence that teachers improvised and dealt with situations as they rose. The findings of this study provided evidence that participation in the OLC had significant impacts on teachers’ professional learning. Teachers altered their mode of using technology either as a partner or as an extension of self as they gained more confidence in their own learning. The teachers gradually transformed their participation from peripheral to full participation in promoting the use of technology for teaching mathematics. The research provides new insights into ways teachers can be helped to develop their professional learning in the use of technology for teaching mathematics through participation in OLCs. Particularly for Indonesia, the findings of this research provide an OLC-based model that could be implemented in other contexts that share similar technology landscapes and sociocultural heritages

Structural behaviour of circular concrete filled steel tube column fill with selfcompacting concrete incorporating coal bottom ash as fine aggregate replacement

Lack of compaction may affect the interaction between the steel tube and the concrete, hence influence the behaviour of CFST column. Employing selfcompacting concrete (SCC) in CFST column as an infill concrete remove the necessity for compaction. However, higher volume of fine aggregate required in SCC makes SCC less preferable. The objective of this research was to investigate the behaviour of circular CFST column filled with SCC incorporating coal bottom ash (CBA) as fine aggregate replacement. In this research work, sand was replaced with CBA at 10%, 15%, 20%, 25%, and 30% of replacement levels. Tests for compressive strength, split tensile strength, flexural strength, and water absorption were performed on specimens at 7 and 28 days curing age. The testing results show that 15% of CBA was the optimum percentage suitable used in SCC. In studying the behaviour of CFST columns, 18 CFST column specimens were tested to fail under the axial compression loading. From the experimental results, it can be concluded that the utilisation of SCC with CBA in the CFST column able to improve the behaviour of CFST column. From compression testing results, the strength of CFST column filled with SCC with CBA increased about 45-50%. The experimental results were also compared with the design standard of Eurocode 4 (EC4). From the comparison, the EC4 conservatively predicts the strength of the column specimens. For instance, EC4 conservatively predicted the column strength in series I by about 21-31%. The finite element analysis (FEA) was conducted on the long column to verify the experimental results and from the FEA result, the predicted value for specimens with 140 mm diameter is 0.005% closer to the experimental results. These discoveries are significant as they showed that the utilization of CBA in SCC as an infill in CFST column able to provide the same strength as CFST with normal SCC. Besides, the use of CBA as partially replacement to the sand will help in more sustainable SCC production by lowering energy and raw material consumption

An impulsive noise analyser using amplitude probability distribution (APD) for broadband-wired communication

Electromagnetic interference or noise which is of impulsive nature is known to affect data communication performance. It is useful to correlate the characteristics of the noise with the bit error probability (BEP). The amplitude probability distribution (APD) has been proposed within CISPR for characterisation of the impulsive noise. However, there is no analyser available to perform direct measurement of the noise within the bandwidth of asymmetric digital subscriber line (ADSL2+) communication. This research presents a novel development of APD analyser for measurements of impulsive noise emission and its impact on ADSL2+ communication. A unique noise APD pattern is obtained from each measurement of noise emission from different electrical and electronic appliances. It is vital to have correct measurement set-up, signal power level, sampling rate, sample points and filter characterisation in order to acquire accurate data representation of the noise patterns. The APD graph is generated by the analyser using the APD algorithm method which employs the envelope sampling technique from actual probability. The noises are characterised using α-stable distribution which exhibits its own distinct APD parameters. The APD curve can be related with the single modulation scheme communication channel performance for estimation of bit error probability. The analyser has been developed successfully with dynamic range of 70 dB higher than the 60 dB CISPR 16 requirement, 0.02 dB amplitude resolution compared to 0.25 dB CISPR 16 requirement and 0.59 dB amplitude accuracy compared with the CISPR 16 standard of +/- 2.7 dB. In addition, the limits for noise in copper cable have been proposed for estimating the severity of the interference towards digital communication performance in ADSL2+ system. An advantage of the analyser is its ability to not only record the noise but the ability to regenerate back the noise which can be used for further analysis. In conclusion, the analyser can provide a comprehensive platform for impulsive noise interference verification towards ADSL2+ communication performance

Fiscal Policy Coordination in Asia: East Asian Infrastructure Investment Fund

East Asian countries were seriously affected by the 2008 global crisis through a steep fall in exports. This experience exposed the vulnerability of the East Asian growth model and emphasized the importance of generating regional growth by expanding domestic demand and enlarging intra-regional trade. A key factor to achieving higher regional economic growth and enlarging intra-regional trade is the better connectivity of infrastructure such as roads, ports, airports, and rail links. Although some East Asian countries have made large investments in improving their infrastructures, others still lag behind. In response to the global crisis, East Asian countries have allocated a significant proportion of their stimulus packages to infrastructure development. While these investments have improved national facilities, East Asian countries will only be well connected when there are good cross-border infrastructures in place. This requires a large amount of funding, and funds from both within and outside the region could be mobilized to fulfill these huge financing needs. Hence, an East Asian Infrastructure Investment Fund (EAIIF) is proposed to provide a mechanism to organize this funding and to be a platform for deciding on cross-border infrastructure projects. The EAIIF would be anchored to the existing Association of Southeast Asian Nations+3 mechanism with the leader's summit being the apex of the decision making process. A four-level mechanism is proposed, consisting of cooperation amongst political leadership; a steering committee and secretariat for executing the decisions of the leaders; fund mobilization; and the implementation and monitoring of projects. Projects chosen could be those with a high rate of commercial returns or those with the highest social benefits. The EAIIF would invite the private sector to participate by setting a framework for the sharing of risks between the public and private sectors. Likewise, there would also be a sharing of risks between countries.East Asian Infrastructure Investment Fund; regional crossborder infrastructure investment

Design of Prototype Dynamic Ac Power Machine with Equivalent Circuit Modeling (Torque Speed Curve of Induction Motor 1,1, Kw)

Squirrel cage induction motors are widely used in electric motor drives due to their satisfactory mechanical characteristics (torque, current, overloading) and small dimensions, as well as their low price. When starting an induction motor, a large current is required for magnetizing its core, which results in a low power factor, rotor power losses and a temperature rise in the windings. None of these parameters should reach values beyond certain limits until the motor reaches nominal speed. The speed of an induction motor 1,1kW is affected very little by fluctuations of voltage. The greater the supply voltage of the motor, the induction motor's speed will increase. The torque values (Tstart, TSmax and Tmax) are affected by the value of the motor supply voltage: (Vp-nl : 132.8, Tstart1 : 7.4, T S-max1 : 0.4, Tmax1 : 9.9) V, (Vp-nl : 127.0, Tstart2 : 4.8, T S-max1 : 0.3, Tmax1 : 8.4) V and (Vp-nl : 121.3, Tstart3 : 3.3, T S-max3 : 0.2, Tmax3 : 7.1) V. Stator current (IL-nl ; 2.5, 2.2, 1.9 ) Amp rises gradually on account of the increase in magnetising current (Im : 2.5, 2.2, 1.9) Amp. The magnetising current required to produce the stator flux. The component of the stator current which provides the ampere-turns balancing the rotor ampere-turns will steadily diminish as the rotor current (IL-nl) decrease with the increase in rotor speed (nr).&nbsp

New extremal binary self-dual codes of length 68 from quadratic residue codes over f_2+uf_2+u^2f_2

In this work, quadratic reside codes over the ring F2 +uF2 +u^2F2 with u^3 = u are considered. A duality and distance preserving Gray map from F2 + uF2 + u^2F2 to (F_2)^3 is defined. By using quadratic double circulant, quadratic bordered double circulant constructions and their extensions self- dual codes of different lengths are obtained. As Gray images of these codes and their extensions, a substantial number of new extremal self-dual binary codes are found. More precisely, thirty two new extremal binary self-dual codes of length 68, 363 Type I codes of parameters [72; 36; 12], a Type II [72; 36; 12] code and a Type II [96; 48; 16] code with new weight enumerators are obtained through these constructions. The results are tabulated.Comment: Under revie