The project was performed in collaboration with the company Prevas AB. The aim of the project was to implement a GPS tracking device, or a GPS tracker, that has a hardware setup retrieving the GPS position of an object and then sends the position through a mobile communication module to a smartphone. A software application running on a smartphone simulator was developed to visualize the position with a Google map widget. The hardware unit consists of a GPS/GSM/GPRS module, a microcontroller, and a smartphone simulator that runs the software application made for iOS, Android and Linux operating systems using Flutter - an UI multi-platform software development kit. Implementation of the setup started with a Telit GM862 GSM/GPRS/3G-GPS module (together with a SmartGM862 development board), an Arduino UNO microcontroller board and a logical level converter. This first setup was not successful because a problem with the serial communication between the Telit GSM-GPS module and the Arduino could not be solved.  The second setup was implemented in which an Arduino GSM/GPRS/GPS shield was used with the Arduino board. The serial communication between the shield and the Arduino was functioning properly and a GPS position could be retrieved. The GPS position is published (sent) using a lightweight messaging protocol - MQTT (messaging queuing telemetry transport) through GPRS functions to the smartphone of the destination user.  To visualize the GPS position in a Google map, an Object Tracker app was implemented on the smartphone simulator app (an iPhone in this project) that subscribes and retrieves the GPS position, and then displays it on the map with a red marker indicating the position.  The GPS tracker with the second setup and the app has been tested and proved to work properly. It has, however, much room for improvement and further development, e.g., making the app more user-friendly, and designing and making a PCB so all the components are mounted on one board. It has been noticed in an initiated test that the GPS antenna placement could affect  positioning accuracy. This, thus, needs to be considered for high accuracy.

Denna kandidatrapport behandlar främst arbetsmetodiken gruppen förhöll sig till samt hur dessa metoder och arbetssätt sedan användes i projektet. Rapporten tar även upp aspekter om själva produkten som förverkligades under projektets gång, även om det inte är i fokus. Applikationsområdet för projektet är på kort sikt att hjälpa äldre personer som genomgått ett hälsosamtal att hålla uppsikt över sin hälsa på ett vetenskapligt sätt. På lång sikt är applikationsområdet att människor ska kunna replikera sina kroppar genom medicinska digitala tvillingar för att testa exempelvis effekter av läkemedel, koster och träningsmetoder. Detta är kort sagt ett koncept som har potentialen att revolutionera sjukvården och människors hälsa i en positiv riktning. I slutet av kandidatrapporten återfinns gruppmedlemmarnas individuella undersökningar.

Fluid-structure interactions appear in many industrial applications in the field of energy technology. As the components are more and more pushed to higher performance, taking fluid-structure interaction phenomena into account has a great impact on the design as well as in the cost and safety. Internal flows related to propulsion systems in aerodynamics area are of our interest; and particularly aeroelasticity and flutter phenomena. A new 2D flexible generic model, so called bump, based on previous studies at the division of Heat and Power Technology about fluid-structure interactions is here presented. The overall goal is to enhance comprehension of flutter phenomenon. The current study exposes a preliminary experimental campaign regarding mechanical behaviour on two different test objects: an existing one made of polyurethane and a new one of aluminium. The setup is built in such a way that it allows the bumps to oscillate until 500Hz. The objective is to reach this frequency range by remaining in the first bending mode shape which is indeed considered as fundamental for flutter study. In this manner being as close as possible to the bending flutter configuration in high-subsonic and transonic flows will provide a deeper understanding of the shock wave boundary layer interaction and the force phase angle related to it. The results have pointed out that the bumps can reach a frequency of 250Hz by remaining in the first bending mode shape. The one in polyurethane can even reach frequency up to 350Hz; however, amplitude is higher than the theoretical one fixed to 0.5mm. Then unsteady pressure measurements for one operating point have been performed based on using recessed-mounted pressure transducers with Kulite fast response sensors. Variation amplitudes and phases of the unsteady pressure are thus correlated with the vibrations of the model. The operating point has been defined with respect to previous studies on the same static geometric model in order to use steady state base line; the steady flows appear consistent with each other. The results have pointed out that the shock wave induces strong amplification of the steady static pressure; however, this rise decreases when the reduced frequency increases. Finally some elements regarding propagating waves are suggested in the analysis for deeper investigations on such complex phenomena.

No description available.

Syftet med denna kandidatuppsats i informatik är att undersöka på vilket sätt ramverket Flutter underlättar för dagens apputvecklare i cross-plattformmiljöer. Uppsatsen belyser för- och nackdelar med Flutter utifrån apputvecklare-perspektiv. Det största problemområde från tidigare studier och forskningar inom cross-plattformutveckling är främst den undermåttliga dokumentation samt långa utvecklingstider. Denna kvalitativa studie är fokuserad på dessa problemområden och resultatet presenteras under kapitel 4 ”Resultat”. En analysmodell har utformats och använts i syfte att, för respondenter, svara på relevanta frågor där ramverket Flutter hanterar dessa viktiga problemområden. Slutsatsen av denna studie visar att det finns ett tydligt mönster där ramverktyget Flutter har satsat på att hantera dessa problemområden genom följande styrkor: Verktyget ”Hot Reload” (hjälpmedel som uppdaterar koden för att snabbt se ändringar direkt i simulatorn) Dart (ett programmeringsspråk) Dokumentation (tydlig, alltid i tid och flera olika kommunikationskanaler) Parallellt med kandidatuppsatsen har författaren utvecklat en egen app via Flutter. Syftet med denna app är att underlätta semesterplaneringen åt en avdelning på företaget AFRY. I denna kandidatuppstats används ej författarens egna upplevelser med Flutter som empiri men avslutar uppsatsen med egna reflektioner.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18519号 / 工博第3911号 / 新制||工||1601(附属図書館) / 31405 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 白土 博通, 教授 宮川 豊章, 教授 八木 知己 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This study compares the performance of two popular cross-platform mobile application development frameworks, Flutter and React Native. As the number of mobile users continues to grow, the ability to target multiple platforms using a single codebase is increasingly important for developers and companies. We conducted three manual UI tests; scrolling through a list, testing the camera, and filtering a large dataset to measure the performance of the frameworks in terms of CPU usage, memory usage, and janky frames on an Android device. The results indicate that Flutter may provide better performance in specific situations when compared to React Native. The study contributes to the existing research by providing additional insights into the performance of these frameworks under specific test scenarios.

No description available.

Mobile applications are a critical part of everyday life. Animations in mobile applications demand optimized performance, which developers are persistently striving to achieve. This study examines the performance of mobile applications developed using native approaches for iOS and Android, as well as the Flutter framework for cross-platform approach, while executing animations. This was motivated by the fact that while cross-platform development offers advantages in terms of development efficiency, it often results in decreased performance. Since the field of mobile development is continuously evolving, it is important to explore new capabilities of mobile technologies. The purpose of this study is to understand the differences in CPU and RAM usage between native and cross-platform applications by examining two types of animation implementations, thereby aiming to identify the causes of the performance gap and propose solutions to decrease the performance gap. This study involved experiments, a literature study and an analysis of the results to address the research questions and fulfill the purpose. The findings of this study showed that the cross-platform approach resulted in higher CPU and RAM usage than the native approaches. However, the performance gap was less noticeable in one of the animation implementations. Thus indicating that the performance of mobile applications can be significantly influenced by the choice of animation implementation. Therefore, a strategic approach to mitigating the performance gap could involve careful selection of Flutter widgets or the incorporation of efficient libraries.

No description available.