The smartphone has quickly become the most used device to access the internet. Academic and public concern has been raised if overuse of smartphone technology can have detrimental effects on brain and behavior. Preliminary results suggest that excessive smartphone usage may be linked to impaired inhibitory control. The present study investigates whether such a relationship is present in a sample of healthy individuals with varying degrees of usage. To investigate the proposed relationship, the Stroop color and word task and the stop-signal task was utilized to measure inhibitory control, while screen time was utilized to measure duration of smartphone usage. A Pearson‘s correlation analysis and an independent t-test/Mann Whitney-U test analyzed the results, which did not yield statistical significance.

This diploma thesis is focused on the design and development of applications for mobile devices with Android operating system. The main purpose of this application is to fulfil the requirements of law on the Electronic Records of Sales. The thesis describes the theoretical knowledge which is important in the development of the application and describes the design and the whole implementation of the application. The application is implemented in the Java programming language. The thesis also deals with the description of the problem of electronic records of sales and the analysis of the EET product range.

This thesis deals with theoretical design and practical realization of map editing application. The first chapter is focused on theoretical explanation of the most important terms in GPS describing basic principles and position monitoring possibilities. Further is described block scheme of GPS receiver. Next chapter describes NMEA 0183 protocol which is used for data transfer between GPS module and application. At the end of theoretical part is some information about geodetic system WGS-84 and files for trace recording. Application is creating in .NET Compact Framework in C# language. Application is able to load map in image format. Trace from specific file format can be displayed into map. Application can show currently recording trace too. Trace can be divided on segments according to type roads. Weak signal in record trace can be modified by correction methods. At the end of this thesis are instructions to using created application.

The diploma thesis solves the problem of design and implementation of library for digital signal processing on Android platform. It describes problems with development software on this platform. There is also a debate about portion of Android on market. It describes technologies and ways, that were used for developing an application. It also explains the efficient programming techniques, in some cases, offering alternative solutions and ways. Effectiveness examines from the perspective of processing power and memory consumption. Continues through analysis Android platform architecture, and some features of its system to the description of some of its parts. Gets up to the description of work with the audio data formats, or to work with files and various collections of data. Then description continues with functions and the application itself. The actual library is controlled through the user interface and some other functions. User select parameters of each signal to be processed. The signal can be generated or the recorded sound signal. After selecting the parameters of each filter, the user can play the output signal and observe the change. In other part different instruments are compared and discussed some improvements, which accelerate and improve the entire application. The conclusion summarizes the results and benefits of the entire diploma thesis.

The report deals with creating applications for Pocket PC, designed to aid with terrain mapping process. Topic falls within the field of geographic information systems (GIS), so the text begins with an analysis of related topics such as GIS itself, processed data characteristics or global positioning systems (GPS). Available handheld platforms are discussed and based on analysis of existing commercial application, the requirements on developed program are set. Description of application architecture and some implementation details follow. The conclusion is devoted to testing functionality by mapping the real geospatial object.

This master's thesis deals with application design and implementation of secured communication between smartphones. Analyses issues of cross-platform portability between operating systems, its differences and common features. It shows an overview of Android OS architecture and its individual layers. Thesis describes basic principles of secured communication in the modern cryptography and implementation of application for mobile platforms. Also shows an overview of modern mobile technologies such as NFC (Near Field Communication) and Bluetooth. This thesis reveals basic architecture and the way how it fits into concept of secured communication. It also describes the architecture of application and concept of secured communication, which is then implemented. In conclusion is summarization of achieved results and possible extensions of implemented application.

This thesis describes design and implementation of augmented reality system for Android platform using location sensors. The application serves as a navigation and displays geographical points of interest. Thesis deals with augmented reality on mobile devices, describes design of own framework and mentions the details about implementation of selected problems. Finally, the results are evaluated.

Approximately 80% of the adult and elderly population ≥65 years have not been assessed or treated for a hearing loss, despite the effect a hearing loss has on communication and quality of life (World Health Organization [WHO], 2013a). In South Africa, many challenges to the health care system exist of which access to ear and hearing health care is one of the major problems. This study aimed to develop and validate a smartphone-based digits-in-noise hearing test for South African English towards improved access to hearing screening. The study also considered the effect of hearing loss and English speaking competency on the South African English digits-in-noise hearing test to evaluate its suitability for use across native (N) and non-native (NN) speakers. Lastly, the study evaluated the digits-in-noise test’s applicability as part of the diagnostic audiometric test battery as a clinical test to measure speech recognition ability in noise. During the development and validation phase of this study the sample size consisted of 40 normal-hearing subjects with thresholds ≤15 dB across the frequency spectrum (250 – 8000 Hertz [Hz]) and 186 subjects with normal-hearing in both ears, or normal-hearing in the better ear. Single digits (0 – 9) were recorded and spoken by a N English female speaker. Level corrections were applied to create a set of homogeneous digits with steep speech recognition functions. A smartphone application (app) was created to utilize 120 digit-triplets in noise as test material. An adaptive test procedure determined the speech reception threshold (SRT). Experiments were performed to determine headphones effects on the SRT and to establish normative data. The results showed steep speech recognition functions with a slope of 20%/dB for digit-triplets presented in noise using the smartphone app. The results of five headphone types indicate that the smartphone-based hearing test is reliable and can be conducted using standard Android smartphone headphones or clinical headphones. A prospective cross-sectional cohort study of N and NN English adults with and without sensorineural hearing loss compared pure-tone air conduction thresholds to the SRT recorded with the smartphone digits-in-noise hearing test. A rating scale was used for NN English listeners’ self-reported competence in speaking English. This study consisted of 454 adult listeners (164 male, 290 female; range 16 – 90 years), of which 337 listeners had a best ear 4 frequency pure-tone average (4FPTA; 0.5, 1, 2 and 4 kHz) of ≤25 dB hearing level (HL). A linear regression model identified three predictors of the digits-in-noise SRT namely 4FPTA, age and self-reported English speaking competence. The NN group with poor self-reported English speaking competence (≤5/10) performed significantly (p<0.01) poorer than the N & NN (≥6/10) group on the digits-in-noise test. Screening characteristics of the test improved with separate cut-off values depending on self-reported English speaking competence for the N & NN (≥6/10) group and NN (≤5/10) group. Logistic regression models, that include age in the analysis, showed a further improvement in sensitivity and specificity for both groups (area under the receiver operator characteristic curve [AUROC] .962 and .903 respectively). A descriptive study evaluated 109 adult subjects (43 male, 66 female) with and without sensorineural hearing loss by comparing pure-tone air conduction thresholds, speech recognition monaural performance score intensity (SRS dB) and the digits-in-noise SRT. An additional nine adult hearing aid users (4 male, 5 female) was utilized in a subset to determine aided and unaided digits-in-noise SRTs. The digits-in-noise SRT was strongly associated with the best ear 4FPTA (r=0.81) and maximum SRS dB (r=0.72). The digits-in-noise test had high sensitivity and specificity to identify abnormal pure-tone (0.88 and 0.88 respectively) and SRS dB (0.76 and 0.88 respectively) results. There was a mean signal-to-noise ratio (SNR) improvement in the aided condition that demonstrated an overall benefit of 0.84 dB SNR. A significant individual variability between subjects in the aided condition (-3.2 to -9.4 dB SNR) and unaided condition (-2 to -9.4 dB SNR) was indicated. This study demonstrated that a smartphone app provides the opportunity to use the English digits-in-noise hearing test as a national test for South Africans. The smartphone app can accommodate NN listeners by adjusting reference scores based on a self-reported English speaking competence. The inclusion of age when determining the screening test result increases the accuracy of the screening test in normal-hearing listeners. Providing these adjustments can ensure adequate test performance across N English and NN English listeners. Furthermore, the digits-in-noise SRT is strongly associated with the best ear 4FPTA and maximum SRS dB and could therefore provide complementary information on speech recognition impairment in noise in a clinical audiometric setting. The digits-in-noise SRT can also demonstrate benefit for hearing aid fittings. The test is quick to administer and provides information on the SNR loss. The digits-in-noise SRT could therefore serve as a valuable tool in counselling and management of expectations for persons with hearing loss who receives amplification. / Thesis (PhD)--University of Pretoria, 2017. / National Research Foundation (NRF) / Speech-Language Pathology and Audiology / PhD / Unrestricted

Philosophiae Doctor - PhD / Community wireless mesh initiatives are a pioneering option to cheap ‘last-mile’ access to network services for rural low-income regions primarily located in Sub-Saharan Africa and Developing Asia. However, researchers have criticized wireless mesh networks for their poor scalability; and scalability quantification research has mostly consisted of modularization of per-node throughput capacity behaviour. A scalability quantification model to design wireless mesh networks to provide adequate quality of service is lacking. However, scalability quantification of community mesh networks alone is inadequate because rural users need affordable devices for access; and they need to know how best to use them. Low-cost low-end smartphones offer handset affordability solutions but require smart management of their small capacity battery. Related work supports the usage of Wi-Fi for communication because it is shown to consume less battery than 2G, 3G or Bluetooth. However, a model to compare Wi-Fi battery consumption amongst different low-end smartphones is missing, as is a comparison of different over-the-top communication applications.

The demand for control systems that are highly capable of driving solid-state optoelectronic devices has significantly increased with the advancement of their efficiency and elevation of their current consumption. This work presents a closed-loop control system that is based on a microcontroller embedded system capable of driving high power optoelectronic devices. In this version of the system, the device in the center of control is a high-power red, green, and blue light emitting diode package. The system features a graphical user interface, namely an Android mobile phone application, in which the user can easily use to vary the light color and intensity of the light-emitting device wirelessly via Bluetooth. Included in the system is a feedback mechanism constituted by a red, green, and blue color sensor through which the user can use to observe feedback color information about the emitted light. The system has many commercial application including in-door lighting and research application including plant agriculture research fields.