Over the past 10 years online video streaming has seen a tremendous increase in popularity, as it has become a great source of both entertainment and education. This increase in popularity has led to demands for higher quality streams, shorter buffering time and service adaptivity, based on the user’s personal prerequisites. These demands together with a constant increase in Internet usage have posed several challenges for streaming service providers to overcome. Within this master thesis an exploratory research and development project has been conducted. The project’s purpose has been to investigate common approaches, standards and trends related to establishing a multimedia streaming service. Based on the results from these investigations, the purpose has furthermore been to design and implement a proof-of-concept streaming server fulfilling the thesis internship company’s needs and requirements. Research has concluded that there are at least five vital components, which have to be carefully considered in order to establish a successful streaming service. These vital components are; the service system structure, the service application programming interface (API), the service hosting solution, the service data storage solution and finally the actual streaming module. Based on results from conducted investigations of common design approaches for each vital component, decisions for the thesis project implementation have been made. The resulting system has been built using the event-based system structure framework Node.js. A representational state transfer (REST) API has furthermore been implemented for managing client request routing. The resulting system has been implemented on a self-hosted server solution even though this is neither a preferred choice in theory nor common practice. The decision has however been made due to future plans at the thesis internship company of investing in a corporate-wide cloud-based server solution. For the service data storage solution the relation-based database management system MySQL has been implemented. For the final recognized vital component, the streaming module, support for HTTP-based multimedia streams has been implemented. This choice of technique has been made due to the many benefits brought on by using HTTP, such as cost efficiency and bandwidth optimization. The use of HTTP is also currently a trending choice of technique Thesis for Master’s Degree at HIT and LiU within the streaming community due to the recently published standard MPEG-DASH.

Natural disasters disrupt our daily life and cause many sufferings. Among the various natural disasters, flood is one of the most catastrophic. Assessing flood risk helps to take necessary precautions and can save human lives. The assessment of risk involves various factors which can not be measured with hundred percent certainty. Therefore, the present methods of flood risk assessment can not assess the risk of flooding accurately.  This research rigorously investigates various types of uncertainties associated with the flood risk factors. In addition, a comprehensive study of the present flood risk assessment approaches has been conducted. Belief Rule Base expert systems are widely used to handle various of types of uncertainties. Therefore, this research considers BRBES’s approach to develop an expert system to assess the risk of flooding. In addition, to facilitate the learning procedures of BRBES, an optimal learning algorithm has been proposed. The developed BRBES has been applied taking real world case study area, located at Cox’s Bazar, Bangladesh. The training data has been collected from the case study area to obtain the trained BRB and to develop the optimal learning model. The BRBES can generate different "What-If" scenarios which enables the analysis of flood risk of an area from various perspectives which makes the system robust and sustainable. This system is said to be intelligent as it has knowledge base, inference engine as well as the learning capability.

The Representational State Transfer (REST) architecture style surfaced quickly to be the favorable scheme to standardize the communication for network-based hypermedia systems due to its uniform discipline. As a result, various giant web services adopted the REST architecture as their primary architectural choice for their services. Regardless of the REST style's uniform discipline, de-facto practices appeared among REST services. Consequently, numerous studies have analyzed REST services and found to a significant extent, misalignments between the theoretical aspects of REST and the practices of REST. One of the studies examined a set of services that claimed to be REST against a class of 17 design criteria that realize the principles of the REST architecture, and it found that the majority of the subject services were inconsistent in applying the REST principles. This study has followed the research mentioned earlier and examined a limited set of REST services and surveyed REST practitioners to examine their practices against the same class of the 17 design criteria to determine to what extent they are applying the 17 design criteria and analyze the statistical differences between the practices of REST services and the practices of REST practitioners. The study results show that REST services and REST practitioners applied most of the 17 design criteria. However, the study also found heterogeneous practices in REST services that go against the principles of the REST style. Furthermore, the statistical analysis results suggest a misalignment between the practices of REST services and REST practitioners in relation to the 17 design criteria.

RESTful services are becoming increasingly popular. This work, that was carried out at Scania IT, investigates how a RESTful service should be designed and specified so that it meets the demands of an enterprise environment. In particular, this report will focus on documentation and validation of RESTful services, i.e. specifications. These are important aspects in an enterprise environment. The investigation consists of a comparative case study of four specification formats and Hypermedia As The Engine Of Application State (HATEOAS). The results show that the most commonly used specification formats have flaws. They also suggest that Swagger and RAML (RESTful API Modeling Language) are the two most mature formats. The results also show that HATEOAS, which is a more dynamic approach, can be useful in an enterprise environment but that it requires careful design. / REST-tjänster blir alltmer populära. Detta arbete, som utfördes på Scania IT, undersöker hur en REST-tjänst bör designas och specifieras för att möta de krav som finns i en enterprise-miljö. Specifikt kommer denna rapport att fokusera på dokumentation och validering av REST-tjänster, med andra ord specifikationer. Dessa är viktiga aspekter i en enterprise-miljö. Undersökningen består av en jämförande fallstudie med fyra specifikationsformat samt Hypermedia As The Engine Of Application State (HATEOAS). Resultaten visar att de mest vanligt förekommande specifikationsformaten har brister. De antyder också att Swagger och RAML (RESTful API Modeling Language) är de två mest mogna formaten. Resultaten visar också att HATEOAS, som är ett mer dynamiskt angreppssätt, kan vara användbart i en enterprise-miljö men att det kräver omsorgsfull design.

The utilization of Application Programming Interfaces (APIs) has experiencedsignificant growth due to the increasing number of applications being devel-oped. APIs serve as a means to transfer data between different applications.While RESTful has been the standard API since its emergence around 2000,it is now being challenged by Facebook’s GraphQL, which was introducedin 2015. This study aims to fill a knowledge gap in the existing literatureon API performance evaluation by extending the focus beyond read opera-tions to include CREATE, UPDATE, and DELETE operations in both REST-ful APIs and GraphQL. Previous studies have predominantly examined theperformance of read operations, but there is a need to comprehensively un-derstand the behavior and effectiveness of additional CRUD operations. Toaddress this gap, we conducted a series of controlled experiments and anal-yses to evaluate the response time and RAM utilization of RESTful APIsand GraphQL when executing CREATE, UPDATE, and DELETE operations.We tested various scenarios and performance metrics to gain insights into thestrengths and weaknesses of each approach. Our findings indicate that con-trary to our initial beliefs, there are no significant differences between the twoAPI technologies in terms of CREATE, UPDATE, and DELETE operations.However, RESTful did slightly outperform GraphQL in the majority of tests.We also observed that GraphQL’s inherent batching functionality resulted infaster response times and lower RAM usage throughout the tests. On the otherhand, RESTful, despite its simpler queries, exhibited faster response times inGET operations, consistent with related work. Lastly, our findings suggestthat RESTful uses slightly less RAM compared to GraphQL in the context ofCREATE, UPDATE, and DELETE operations.

Mobile money, a means of transferring payments via mobile devices, has become increasingly popular. The demand for convenient financial products or services is a crucial factor in why innovative developers want to incorporate mobile money into existing financial products/services. The goal is to provide convenient financial services that enable customers to quickly send and receive money between two mobile payment platforms. The Swedish blockchain company, Centiglobe, is searching for a system whereby payments can be made conveniently between two mobile payment platforms, specifically Alipay and M PESA. This thesis sought to develop such a system by utilizing the application programming interfaces (APIs) (provided by Alipay and M PESA) coupled with Centiglobe’s blockchain to facilitate payments between an Alipay user and an M PESA user. Solving this problem began with an initial literature study of previous work related to this topic and reading the extensive API documentation provided by Alipay and Daraja Safaricom (the developers of M PESA). Next, a flowchart was created and used as a guide throughout the development of the system. Testing the system entailed integration testing. The performance of the system was determined by measuring the execution time to make a cross system payment. A one-way transfer system was developed, as Alipay users can make a payment to M PESA users but not the reverse. The results of the integration testing shows that the system is a feasible solution. The execution time of a payment shows that it is relatively quick (~9.1 seconds); thus the performance is adequate.The conclusion is that this system is a viable solution for incorporating Alipay and M PESA as mobile payment services. Moreover, the system partially facilitates person-to-person payments between them – subject to the limitations of the Alipay API. In addition, this system provides a foundation for other inter-platform mobile payment solutions. / Mobila pengar, ett sätt att överföra betalningar via mobila enheter, har blivit alltmer populära. Efterfrågan på praktiska finansiella produkter eller tjänster är en avgörande faktor för varför innovativa utvecklare vill integrera mobila pengar i befintliga finansiella produkter / tjänster. Målet är att tillhandahålla praktiska finansiella tjänster som gör det möjligt för kunder att snabbt skicka och ta emot pengar mellan två mobila betalningsplattformar. Det svenska blockchainföretaget Centiglobe söker ett system där betalningar kan göras bekvämt mellan två mobila betalningsplattofrmar, särskilt Alipay och M-PESA. Denna avhandling försökte utveckla ett sådant system genom att använda applikationspogrammerinsgränssnitt (API) (tillhandahållet av Alipay och M-PESA) i kombination med Centiglobe’s blockchain för att underlätta betalningar mellan en Alipay-användare och en M-PESA-användare. Lösningen av detta problem började med en första litteraturstudie av tidigare arbeten relaterat till detta ämne samt en omfattande läsning av API-dokmentationen från Alipay och Daraja Safaricom (utvecklarna av M-PESA). Därefter skapades ett flödesschema och detta användes som en guide under hela utvecklingen av systemet. Testning av systemet medförde integrationstestning. Systemets prestanda bestämdes genom att mäta exekveringstiden för att göra ett tvärsystemsbetalning. Ett envägsöverföringssystem utvecklades, eftersom Alipay-användare kan göra en betalning till M-PESA-användare men inte tvärtom. Resultaten av integrationstestningen visar att systemet är en genomförbar lösning. Utbetalningstiden för en betalning visar att den är relativt snabb (~9.1 sekunder); därav en lagom prestanda. Slutsatsen är att detta system är en lönsam lösning för att integrera Alipay och M-PESA som mobila betalningstjänster. Dessutom underlättar systemet delvis personliga betalningar mellan dem – med förbehåll för begräsningarna i Alipay API. Dessutom erbjuder detta system en grund för andra mobila betalningslösningar mellan plattformarna.

Yes / Interoperability within different healthcare systems (clinics/hospitals/pharmacies) remains an issue of further research due to a barrier in sharing of the patient’s Electronic Health Record (EHR) information. To solve this problem, cross healthcare system collaboration is required. This paper proposes an interoperability framework that enables a pharmacist to access an electronic version of the patient’s prescription from the doctor using a RESTFul API with ease. Semantic technology standards like Web Ontology Language (OWL), RDF (Resource Description Framework) and SPARQL (SPARQL Protocol and RDF Query Language) were used to implement the framework using JENA semantic framework tool to demonstrate how interoperability is achieved between a pharmacy and a clinic JENA was used to generate the ontology models for the pharmacy called pharmacy.rdf and clinic called clinic.rdf. The two models contain all the information from the two isolated systems. The JENA reasoner was used to merge the two ontology models into a single model.rdf file for easy querying with SPARQL. The model.rdf file was uploaded into a triple store database created using FUSEKI server. SPARQL Endpoint generated from FUSEKI was used to query the triple store database using a RESTFul API. The system was able to query the triple store database and output the results containing the prescription name and its details in JSON and XML formats which can be read by both machines and humans. / Supported by a Institutional Links grant, ID 261865161, under the Newton-Ristekdikti Fund partnership. The grant is funded by the UK Department for Business, Energy and Industrial Strategy and Indonesia Ministry of Research, Technology and Higher Education and delivered by the British Council.

With more applications accessible on the Web, organizations with mission-critical legacy systems have had to find a way to stay relevant and competitive by modernizing with RESTful APIs. REST architecture, serving as a guideline rather than a strict protocol, offers significant advantages in terms of scalability, flexibility, and independence; however, its widespread adoption has also led to notable security vulnerabilities and weaknesses. Additionally, there is not one all-encompassing security testing methodology to follow when testing RESTful APIs. For this reason, a new security testing methodology was developed for legacy MultiValue Pick systems that implement the REST API component, MVConnect. The steps of the methodology consist of: threat modeling, source code review, penetration testing, and mitigation. A case study involving a legacy D3 MultiValue Pick Database Management System (DMS) implementing MVConnect was assessed following this methodology. Several vulnerabilities were identified, discovered, and exploited including the following: security misconfigurations, broken authentication, broken authorization, session mismanagement, server-side request forgery, and unsafe consumption of APIs. Mitigation solutions were proposed including basic authentication and authorization control mechanisms specific to D3 MultiValue Pick and proper firewall rules to administer. The new security testing methodology enabled a successful security assessment of a legacy MultiValue Pick system that employed MVConnect. The mitigation solutions are capable of securing legacy MultiValue Pick systems implementing MVConnect.