Context. Localization and positioning services are nowadays very extended and the growth is still continuing. Many places already provide wireless tracking systems to monitor the people or material movements, specially indoors. The new arising ZigBee wireless technology provides an efficient network management and a low battery consumption, making it appropriate for location purposes in portable devices like mobile phones. Objectives. The aim is to locate a ZigBee device located inside a golf ball that has been lost within an outdoors area. An Android phone connected to a ZigBee device via USB will serve as coordinator of the localization network and by giving on-screen instructions and guidance provided by the conceptual Decision Support System (DSS). Methods. The measurement used in the localization process is the Received Signal Strength (RSS). With this data, the distance between the sensors can be estimated. However to obtain an accurate position several readings from different sensors might be needed. This paper tests the precision levels of the ZigBee modules varying the number of sensors in the localization network and using the triangulation method. Results. The precision is the main variable measured in the results, which reaches distance variation of less than 1 meter in cases where the triangulation approach can be applied. For the localization process, the use of less than three sensors lead to very poor results, obtaining a wrong localization in around 30\% of the cases. Also, movement patterns were discovered to improve the localization process. All this data can be used as an input for the DSS for future improvements. Conclusions. This study proves that outdoor positioning with ZigBee devices is possible if the required level of precision is not very high. However, more studies concerning localization with less than three sensors have to be conducted to try to reach the goal of one-on-one localization. This study opens the door for further investigations in this matter.

Context. Mobile devices recently have attained huge popularity in people’s life. During recent years, there have been many attempts for proposing several approaches to delegate and execute the computing intensive part of the mobile applications on more powerful remote servers due to shortage of resources on mobile devices. However, there are still research challenges in this area regarding the models as well as principles that govern circumstances of executing a part of mobile application remotely on a server along with effects of execution on the smartphone resources. Objectives. The aim behind conducting this research is to propose a model for executing the service component of an Android application on the remote server. This study exploits the enhancement of Android operating system functionality to execute services components on a remote powerful machine. It reports the model as well as the enhancements to achieve this purpose. Additionally, an experiment is conducted to realize what factors rule to execute a computation locally on mobile device or offload it to be executed on a remote machine. Methods. Two research methodologies have been used in preforming this research; Case study and controlled experiment. In the case study we investigates feasibility of functionality enhancement in Android operating system to run service components of Android applications on a remote server. We propose a new model for this purpose and motivate it by several different resources such as journal and conference papers and the Android developer site. A prototype of the model is implemented in order to put into use in the next part of our study. Second, a controlled experiment is conducted on the outcome prototype of the case study to explore the principles that governs executing the service component of Android application on a remote powerful machines and the affection of this execution on the mobile resources. Results. A Model for executing the service component of Android application on a powerful remote server is proposed. Also, a prototype implemented according to the Model. The effects of executing Android service components in a remote machine on energy consumption as well as performance of a smartphone are investigated. Moreover, we examined when would be beneficial to offload an intensive computation in order to be executed on the remote server. Conclusions. We conclude that it’s applicable to enhance the Android OS to execute service component of an Android application on a remote server. Also, We conclude that there is a strong coloration between amount of payload and computation of data that require to be executed on a remote server. Basically, offloading the computation is beneficial when there is a large amount of computation with small amount of communication and payload. Furthermore we conclude that the execution time for the intensive computations drastically increase when it’s executed on the server but for less computation data the performance is better when the execution is on the smartphone. Besides that, we express that the energy consumption on the smartphone growth gradually when the payload passes over a particular size.

When developing mobile applications, the tradition has been to write code specific (native) for each platform they are running on. Usually it’s about writing two separate applications for the biggest platforms, Android and iOS. There exist alternatives to this approach that uses the same code for different platforms. React Native is a relatively new cross-platform development framework that makes it possible to use the same code for application to Android and iOS. It also uses native UI-elements as a possible solution for performance issues that is often associated with cross-plattform development. This thesis evaluates React Native and compares it against native Android. The implementation is done by replicating the main functionality from a social media application written as a native Android application. However, the application is not made as an exact replica since that could limit the solutions in React Native. The evaluation is done in a Startup company and therefore focuses on aspects important in a Startup. Another issue when developing a mobile application is what type of backend that shall be used. Performance, scalability and complexity are all important aspects when choosing a framework or language as a base for the backend architecture.There do exist theoretical frameworks that could be used when building the backend. However, these frameworks require resources that are often missing in a Startup. AWS Lambda is a platform that claims to be a cost-effective way of building a scalable application. In this thesis AWS Lambda is evaluated to see if it can be used to create an automatically scaled backend for this type of social media application. The conclusion of the React Native evaluation is that it can be a suitable alternative to native Android development. If the team has previous experience in web development but lack experience in mobile application development it can be a wise choice since it removes the need to learn two frameworks in native Android and native iOS development. React Native is also good to fast create functional prototypes which can be shown to potential investors. The biggest drawback is performance in animations. However, there are often ways to work around that. In our case this drawback did not affect the user experience of the end application. The evaluation of AWS Lambda concludes that it is not for every project. In this thesis, the application was a bit too database heavy and therefore the autoscaling ability did not work properly. However, for a service that needs a lot of computing power, AWS Lambda could be a good fit. It could also be a suitable alternative if someone in the team has previous experience in the AWS environment.

Today, it is not unusual that smartphone devices can’t survive even one day of regular use until the battery needs to be recharged. The batteries are drained while using power hungry applications made by developers who haven’t taken their application’s energy impact into consideration. In this thesis we study network transmissions as made by a mobile application, and the impact these have on the battery life. The application was developed with the local rescue and emergency service as a hypothetical target group. We test how the mobile network technologies 3G and WiFi together with the device’s current signal strength and battery level affect the energy usage of the battery when uploading data to a server. We develop an adaptation mechanism on application level which uses a mathematical model for calculating a suitable adaptation of scheduling of network interactions. The adaptation mechanism makes use of burst buffering of packets, and adjusts for 3G tail times as well as for different priorities of incoming requests. Custom packet scheduling profiles are made to make consistent measurements, and with this implementation we are able to reduce the amount of energy consumed using 3G and WiFi with 67 % and 39 % respectively during tests.

Smartphones combine telephony services with data services in a single device. In 2007, Apple released a new generation of phones run by iOS operating system, called iPhones. Android phones were developed by Google and were released the following year. Smartphones use has increased a lot and they have become one of the most common devices that are being used in most of companies nowadays. The concept BYOD stands for Bring Your Own Device, means that employees may use their own smartphones at work. This makes using the built-in security features in smartphones particularly important, not only to protect employees’ private information but also to protect their corporate information. Early research has shown that threats and attacks have also increased on smartphones. Hackers have focused their attacks on smartphones more than before. And have created mobile-based viruses, malware and spyware that target vulnerable smartphones. Smartphone users nowadays do not have much control of their smartphones security according to previous researches. However, smartphones manufacturers constantly add new built-in security features with each new version of operating system to protect them from various threats. Smartphone manufacturers may use the acquired final data to improve their products’ security and increase the use of mobile built-in security features. The current study researches students’ interaction and use of the built-in security features available in smartphones run by both Android and iOS operating systems. The study does not divide students into smaller groups; it rather focuses on all students as one group. Although this study was conducted in the University of Skovde in Sweden, its conclusion can be applied to a bigger population regardless of location. Today's students are tomorrow’s employees and managers who will have the responsibility to protect their companies’ proprietary and sensitive information. Therefore, it is critical that they understand and implement all up-to-date procedures to protect their smartphones and their companies. A quantitative study is conducted through a survey in order to reach as many participants as possible. Lime Survey tool is utilized to create surveys and to gather data. Statistics and diagrams are also used to demonstrate results to readers. A total of 201 participants completed the entire study, 134 participants answered the Android survey and 67 answered the iOS survey. The current survey results have shown, through a model that converts participants’ answers into a flow chart, that the use of the built-in security features varies among participating students. The use of these built-in security features was low in general. More than half of all participants do not use certain functions at all. The general low use of the built-in security features can be attributed to many reasons. This survey showed that the main reason of that was the lack of participants’ knowledge of these built-in security features. Several solutions exist for this lack of knowledge of participants, but they do not fall within the scope of this study therefore not discussed herein.

Nowadays, a lot of interesting and useful and imaginative applications are springing to Android software market. And for guitar fans, some related apps bring great connivence to them, like a guitar tuner can save people from carrying a entity tuner all the time, some apps can simulate a real guitar, and some apps provide some simple lessons allowing people to learn some basic things. But these apps which can teach people, they can't really “monitor ” people, that is, they just give some instructions and hope people would follow them. So my project is to design an app which can detect if users are playing wrong and right real-timely. Guitar chords are always the first for new guitar beginners to learn, and a chord is a set of notes combined together in a regulated way ( get from the music theory having millions of developing ), and 'pitch' is the term for determining if the note different from other notes or noise, so the problem here is to manage the multi-pitch analysis in real time. And it's necessary to know some basics of digital signal processing ( DSP ) because digital signals are always more convenient for computers to analyze compared to analog signals. Then I found an audio processing Java library – TarsosDSP, and try to apply it to my Android project.

Projektgruppen HigTech på Högskolan i Gävle ställer årligen upp i Shell Eco-Marathon, en tävling där det gäller att komma så lång sträcka som möjligt på en liter bensin. Ett datorstöd till föraren har efterfrågats och därför ska en mobilapplikation utvecklas där man tar till vara på de olika sensorer som finns inbyggda. Applikationen ska utvecklas mot Android. Med hjälp av applikationen ska information från GPS och accelerometer samlas in och analyseras. Målet är att ta reda på hur noggranna de relevanta sensorerna är i en smartphone och om det räcker för att användas i Shell Eco-Marathon. Resultatet är en empirisk undersökning som visar att denna teknik kan agera som ett stöd till föraren, samt en grundapplikation utvecklad mot Android.

Målet med detta projekt är att ta fram en applikationsprototyp för Androidenheter som ska locka användare av applikationen till och tillbaka till broparken i Skönsberg med hjälp av augmented-reality. Applikationen ska känna av om användaren befinner sig inom eller utanför parkens område och visa olika bilder/modeller på specifika GPS-koordinater i det digitala lagret beroende på användarens positionering. Arbetet har genomförts i samarbete med Dohi på uppdrag av Sundsvalls kommun där regelbundna möten hafts med uppdragsgivaren. Utvecklingen av applikationen sker i PhoneGap med Wikitude-plugin. Projektet har resulterat i en applikationsprototyp som använder ActionRanges, som är en typ av GeoFence, för att presentera olika bilder hämtade från en egen server i det digitala lagret beroende på användarens position. Användarna har inom parkens område möjlighet att själv påverka de bilder som visas i det digitala lagret genom att i applikationen ta en bild som laddas upp till servern där bilderna lagras och där bilden som tagits även visar det digitala lagret.

Marknaden för mobila system har utvecklats enormt snabbt de senaste åren. Idag är det ett område med en allt större omsättning och det har vuxit fram som en helt ny gren inom Software Engineering. Utvecklare av mobila applikationer står ständigt inför en utmaning när det gäller att välja vilket mobilt system man ska satsa på när man utvecklar applikationer. Valet av system kan vara helt avgörande för om man hittar rätt målgrupp av konsumenter och därmed kan generera tillräckligt med omsättning för att driva lönsam utveckling av applikationer. Det räcker inte att enbart kolla på vilket system som har mest användare eller vilket system som genererar mest omsättning, utan man bör noggrant överväga de förhållande som gäller för just den applikation som ska utvecklas. Genom att följa denna guiden och överväga de olika faktorer som vi har sammanställt så kan man som utvecklare göra ett val som är baserat på aktuella marknadsundersökningar. Även inom andra områden så kan man ha nytta av denna artikel, exempelvis inom den akademiska världen där man utbildar inom mobil utveckling.

In recent years, there has been a great increase in the development of wireless technologies and location services. For this reason, numerous projects in the location field, have arisen. In addition, with the appearance of the open Android operating system, wireless technologies are being developed faster than ever. This Project approaches the design and development of a system that combines the technologies of wireless, location and Android with the implementation of an indoor positioning system. As a result, an Android application has been obtained, which detects the position of a phone in a simple and useful way. The application is based on the WIFI manager API of Android. It combines the data stored in a SQL database with the wifi data received at any given time. Afterwards the position of the user is determined with the algorithm that has been implemented. This application is able to obtain the position of any person who is inside a building with Wi-Fi coverage, and display it on the screen of any device with the Android operating system. Besides the estimation of the position, this system displays a map that helps you see in which quadrant of the room are positioned in real time. This system has been designed with a simple interface to allow people without technology knowledge. Finally, several tests and simulations of the system have been carried out to see its operation and accuracy. The performance of the system has been verified in two different places and changes have been made in the Java code to improve its precision and effectiveness. As a result of the several tests, it has been noticed that the placement of the access point (AP) and the configuration of the Wireless network is an important point that should be taken into account to avoid interferences and errors as much as possible, in the estimation of the position.