Search results

Since the introduction of Apple's App store and Google's Android Market (now Google Play) around the middle of 2008, the applications (commonly called Apps) for the iPhone and Android-based phones have surpassed 500,000 for each of the platforms. There are Apps for just about anything one can imagine. In the very near future, the use of smartphones and tablet devices for gathering information from the Web and for learning is expected to exceed the PC's and laptops. Given this, the design, development, and deployment of mobile Apps that support learning would be highly beneficial to students and learners. Such Apps could act as very effective supplements to the exiting learning modalities, especially in the areas of Math, Science, and Engineering, where most students have to grapple with abstract and hard concepts. This paper presents the approaches and design elements of an App for presenting concepts in mathematics and engineering.

In this chapter, we investigate the role of the Internet of Things (IoT) for a more sustainable future. The IoT is an umbrella term that refers to an interrelated network of devices connected to the internet. It also encompasses the technology that enables communication between these devices as well as between the devices and the cloud. The emergence of low-cost microprocessors, sensors and actuators, as well as access to high bandwidth internet connectivity, has led to the massive adoption of IoT systems in everyday life. IoT systems include connected vehicles, connected homes, smart cities, smart buildings, precision agriculture, among others. During the last decade, they have been impacting human activities in an unprecedented way. In essence, IoT technology contributes to the improvement of citizens' quality of life and companies' competitiveness. In doing so, IoT is also contributing to achieve the Sustainable Development Goals (SDGs) that were adopted by the United Nations in 2015 as an urgent call to action by all countries to eradicate poverty, tackle climate change and ensure that no one is left behind by 2030. The World Economic Forum (WEF) recognises that IoT is undeniably one of the major facilitators for responsible digital transformation, and one of its reports revealed that 84% of IoT deployments are presently addressing, or can potentially address the SDGs. IoT is closely interlinked with other emerging technologies such as Artificial Intelligence (AI) and Cloud Computing, for the delivery of enhanced and value-added services. In recent years, there has been a push from the IoT research and industry community together with international stakeholders, for supporting the deployment and adoption of IoT and AI technologies to overcome some of the major challenges facing mankind in terms of protecting the environment, fostering sustainable development, improving safety and enhancing the agriculture supply chain, among others.

The purpose of this paper is to discuss the possibility of using soldering process for the bonding of chip-on-flexible (COF) light-emitting diode (LED) packages to heat sinks. The common bonding materials are thermal conductive adhesives. For thermal performance and reliability concerns, Tin-Bismuth (SnBi) lead-free solder paste was used for the connection of the COF packages and the Cu heat sinks by a soldering process in this study. Meanwhile, the geometrical effect of the SnBi solder layer on the thermal performance was also investigated.

The effects of the bonding materials and the area of the solder layers on the thermal performance of the LED modules were investigated by finite element simulation and experimental tests.

The SnBi soldered modules show much lower thermal resistance at the bonding layers than the adhesive-bonded LED module. Vertical heat transfer from the LED chips to the heat sinks is the primary heat dissipation mode for the SnBi soldered modules. Thus, the LED module with local solder layer shows similar LED thermal performance with the full-area soldered module. Meanwhile, the local soldering process decreases the possibility to form randomly distributed defects such as the large area voids and residue flux in the solder layers.

The research is still in progress. Further studies mainly focus on the reliability of the samples with different bonding materials.

COF package is a new structure for LED packages. This study provides a comparison between SnBi solder and adhesive material on the thermal performance of the LED. Meanwhile, the authors optimized the geometrical design for the solder layer. The study provides a feasible bonding process for COF packages onto heat sinks.

This study provides a soldering process for the COF LED packages. The thermal performance of the LED light source was improved significantly by the new process.

The use of mobile wireless data services continues to increase worldwide. New fourth‐generation (4G) wireless networks can deliver data rates exceeding 2 Mbps. The purpose of this paper is to develop a framework of 4G mobile applications that utilize such high data rates and run on small form‐factor devices.

The author reviews existing literature of mobile applications development and proposes using network‐related characteristics to create a conceptual framework of these applications.

Combining traffic symmetry and latency yields a 2×3 framework with six categories that characterize current and emerging 4G mobile applications, such as augmented reality, mobile social networking and m‐health.

With the advent of high‐speed 4G networks, completely new mobile applications can be developed to leverage such high data rates, and a framework of such development efforts is highly desirable.

The framework is developed based on a perspective of technical characteristics because these characteristics intrinsically constrain the kinds of broadband mobile applications that can be developed. The framework should be useful in exploring opportunities of mobile application development and guiding future research in this area.

It is essential to understand how the countries with the highest number of tourist arrivals have managed to recover or not based on the competitiveness of the tourism industry during the pandemic stage. It is necessary to evaluate the policies implemented by each government to maintain the competitive performance of their industries. This chapter proposes a comprehensive review of the policies implemented in the 10 most visited countries according to UNWTO data. Most of these policies are geared toward economic and financial flexibility strategies for companies and individuals in the industry under study. The effectiveness of these policies is evaluated with statistical information extracted from a unified UNWTO database to reduce biases in the effectiveness analysis. Finally, concluding remarks are offered on the effectiveness of the policies and their contribution to the sector's recovery.

The purpose of this paper is to study the corrosion behavior of as‐cryorolled and cryorolled‐short annealed commercially pure aluminum (CP‐Al) in 3.5 percent NaCl solution.

Cast and homogenized CP‐Al samples are cryorolled from 7 to 0.7 mm at −80°C. Samples are short annealed at 125, 150 and 175°C for 3 min. Transmission electron microscope studies are performed to understand the effect of cryorolling and short annealing on microstructure. Corrosion behavior of these samples in 3.5 percent NaCl solution is evaluated by potentiodynamic polarization studies.

Though cryorolling adversely affects corrosion resistance of CP‐Al, short annealing can restore the loss in corrosion resistance partially by the recovery process. The extent of restoration of loss in corrosion resistance by short annealing is influenced by the texture.

The results obtained by this investigation help in understanding the effect of cryorolling and short annealing on corrosion behavior of CP‐Al.

People can easily track and understand their usage pattern for any content (e.g. movies, games) or service (e.g. card payment, cell phone usage) by using technologies such as the internet and smart phones. When consumers evaluate their past consumption patterns, they may experience two different kinds of regret: content-based or monetary-based. The purpose of this paper is to propose that perceived self-control, defined as the extent to which people believe they can control their usage, plays a moderating role in the tariff-choice process (flatrate vs pay-per-use) for two types of content: vice-based and virtue-based.

Two laboratory experiments were designed to test the hypotheses. There were a total of 200 participants (86 for Experiment 1 and 114 for Experiment 2) who completed the entire experimental process (i.e. stimulus exposure, questionnaire reporting, dependent variable measurement, manipulation of the independent variables, and control checks).

The results of this research provide evidence supporting the role of perceived self-control in tariff preference by showing that preference varies between flat-rate and pay-per-use tariff options. Specifically, virtue-based content users were more likely to prefer the pay-per-use tariff when their perceived self-control was low vs when it was high. In contrast, vice-based content users were more likely to prefer the flat-rate tariff when their perceived self-control was low vs when it was high.

There are three contributions of the present research. First, the authors investigated the effect of content type on tariff preference. Second, the authors suggest that there is a moderating effect of perceived self-control on tariff preference. Third, this study revealed the factors affecting consumers’ perceived self-control.

This paper aims to study the information needs and online information-seeking behaviors on mobile platforms of performing arts students at a college level.

Survey instruments were used to collect data from performing arts students at the Hong Kong Academy of Performing Arts (HKAPA), a metropolitan’s major performing arts tertiary institution. Data collected were analyzed through descriptive statistics and other statistical methods, and the music-related students were compared with the production-related students.

The result reveals that performing arts students all owned their mobile devices and often used mobile apps for non-academic purposes, but they did not often use mobile library services or read online academic contents with their mobile devices. The participants considered inadequate signal coverage, slow loading time, difficulty in reading on a mobile device and the lack of specialized mobile apps as more significant barriers affecting their usage. There are some significant differences between the music-related and production-related student groups in that music-related students watched lectures on the library websites and used electronic music scores more often than the production-related students.

This study contributes to the input for enhancements and policies to future mobile services and facilities of performing art libraries.

There have been scant studies on the mobile learning needs of performing arts students, especially in Asia.

Aluminium matrix composites are subjected to wear as well as higher temperature applications such as pistons, cylinder heads and blocks for car engines. Therefore, it is important to evaluate the performance of aluminium metal matrix composite at elevated temperature.

In the present work wear performance of Al-TiC composite with 7.5% reinforcement of TiC powder is carried out at elevated temperature. The composite specimens are prepared with the help of centrifugal casting method to get the large segregation of reinforcement on the outer layer of the composite which is subjected to wear. Taguchi method is used for preparing design of experiments.

The wear test is performed on DUCOM pin on disc setup having the heating chamber facility. The results of wear test are analysed with the help of MINITAB 19 software. The results show that temperature has dominant effect on the wear rate. The mathematical model through regression is predicted for wear rate and coefficient of friction. The study of worn-out surface is performed with the help of scanning electron microscope. The micrographs show that the type of wear is changes from abrasive to severe wear and some delamination.

The experiments are conducted as per ASTM standards. The results give the mathematical equation for wear rate and coefficient of friction at elevated temperatures.

The paper aims to describe the Taguchi design method-based abrasive wear modeling of in situ AlB2 flake reinforced Al-4Cu matrix alloy composites.

The abrasive wear behaviors of the composite samples were investigated using pin-on-disk method where the samples slid against different sizes of SiC abrasive grits under various testing conditions. The orthogonal array, signal-to-noise (S/N) ratio and analysis of variance were used to study the optimal testing parameters on composite samples.

The weight loss of composites decreased with increasing grit size and percentage reinforcement and increased with increasing sliding speed. The optimum test condition, at which the minimum weight loss is obtained, has been determined to be A3B3C1 levels of the control factors. Deviations between the actual and the predicted S/N ratios for abrasive weight losses are negligibly small with 99.5 per cent confidence level.

This paper fulfils an identification of Taguchi method-based abrasive wear behavior of AlB2/Al-4Cu metal matrix composites produced by squeeze casting under various testing conditions.