Software developers often encapsulate reusable code as Application Programming Interfaces (APIs). The co-evolution of applications and APIs may motivate an API migration: the replacement of application dependencies to an original API by dependencies to an alternative API that provides similar functionality and abstractions. In this dissertation, we investigate issues associated with API migration in object-oriented systems, with special focus on wrapping approaches. We present two studies and a set of developer interviews that elicit issues in the process and techniques used in API migration in practice. The results suggest that the most pressing issues relate to discovery and specification of differences between APIs, and to assessment of migration correctness. This dissertation introduces techniques and a method to address these issues. We propose the use of design patterns to support the specification of API wrappers. API wrapping design patterns encode solutions to common wrapping design problems. We present an initial catalog of such patterns that were abstracted from programming idioms found in existing API wrappers. We introduce the concept of compliance testing for API migration, a form of automated testing. Compliance testing supports the discovery of behavioral differences between a wrapper and its corresponding original API, as well as assessment of wrapper correctness. Compliance testing uses API contracts and assertion tunings to explicitly capture and enforce the notion of a “good enough” wrapper that is informal in practice. We present the Koloo method for wrapper-based API migration. The method prescribes practical steps to use compliance testing as a means to elicit the requirements for the API migration, and to assess its correctness. Koloo fits within the iterative, sample-driven general API migration process usually followed by developers in practice. We evaluate the Koloo method in an empirical study. The subjects cover the domains of XML processing, GUI programming and bytecode engineering. The results provide evidence that Koloo is superior to alternative methods in driving the development of a wrapper that is tailored for the application under migration. The results also show that API contracts help driving the evolution of the wrapper, and assertion tuning is necessary to relax the semantics of strict equality contracts, and useful to compromise on features that are difficult to emulate perfectly. Finally, we validate that the proposed design patterns are used in practical wrappers.

<p>Detta examensarbete behandlar problemet med att testa inbyggda system i kontorsmiljö. För att göra detta och därigenom kunna göra anrop på det inbyggda systemets API, måste detta anrop skickas som ett seriellt datapaket över en seriell kommunikationslänk som TCP/IP.</p><p>Detta möjliggjordes genom att först upprätta en kommunikationslänk med protokollet TCP/IP, där användningen av POSIX-sockets tillämpades. För att packa ner och packa upp funktionsanropen till seriell data implementerades ett protokoll som följdes när detta utfördes. Hantering av data i samband med överföring över TCP/IP sköttes av ett protokoll vid namn BGSFP, ett protokoll som bygger på det tidigare protokollet TSFP.</p>

Målet med detta projekt har varit att, till en ny digital handelsplats, ge ett förslag till en implementation av MongoDB, med tillhörande REST-API, för hantering av användar- och annonsdata. Förslaget ska innebära en prestandaeffektiv och säker databas med möjlighet till framtida skalning, tillsammans med ett API för klientkommunikation med hantering av relevanta förfrågningar mot databasen. Prestandan av databasen handlar främst om att i förslaget ange vilka olika former av indexering som bör implementeras, tillsammans med ett förslag till relationsmodell, och vad detta ger för positiva och negativa effekter på systemet. Denna prestanda bör även återspeglas till största möjliga mån i API:et genom att utnyttja den indexering som väljs på bästa sätt. Säkerhet och skalning diskuteras under arbetet för att ge ett förslag på hur detta bäst hanteras för minimera riskerna för dataförlust, samt minimera nedtiden av databasen vid en eventuell framtida skalning. Resultatet visar att de förslag som arbetats fram under projektets gång har stor positiv påverkan på prestandan, samt möjliggör bland annat fritextsökningar och geografisk gallring av annonssökningar, baserat på användarens geografiska position, genom användande av olika typer av index. / <p>Presentationen utförs per distans via Adobe Connect.</p>

With the advancement of internet technology, online news content has become very popular. People can now get live updates of the world's news through online news sites. Social networking sites are also very popular among Internet users, for sharing pictures, videos, news links and other online content. Twitter is one of the most popular social networking and microblogging sites. With Twitter's URL shortening service, a news link can be included in a tweet with only a small number of characters, allowing the rest of the tweet to be used for expressing views on the news story. Social links can be unidirectional in Twitter, allowing people to follow any person or organization and get their tweet updates, and share those updates with their own followers if desired. Through Twitter thousands of news links are tweeted every day. Whenever there is a popular new story, different news sites will publish identical or nearly identical versions (``clones'') of that story. Though these clones have the same or very similar content, the level of popularity they achieve may be quite different due to content agnostic factors such as influential tweeters, time of publication and the popularities of the news sites. It is very important for the content provider site to know about which factor plays a important role to make their news link popular. In this thesis research, a data set is collected containing the tweets made for the 218 members of 25 distinct sets of news story clones. The collected data is analyzed with respect to basic popularity characteristics concerning number of tweets of various types, relative publication times of clone set members, tweet timing and number of tweeter followers. Then, several other factors are investigated to see their impact in making some news story clones more popular than others. It is found that multiple content-agnostic factors i.e. maximum number of followers, self promotional tweets plays an impact on news site's stories overall popularity, and a first step is taken at quantifying their relative importance.

Hydrophilic polymers in a swellable matrix tablet hydrate quickly to form a hydrogel layer on the exterior of the dosage once in contact with water or biologic fluid. The resultant hydrogel serves as a barrier to regulate water permeation into the matrix and drug diffusion from the preparation. It is therefore important to understand how the polymer is hydrated and what mechanism exists between hydrogel formation and drug dissolution from a swellable matrix tablet. In this thesis, a TA texture analyzer was utilized to monitor and characterize matrix swelling properties during dissolution process. Multiple regression models were employed to analyze the quantitative relationship between drug dissolution or hydrogel thickness and major formulation factors (polymer ratio, drug solubility). Modified release matrix tablets were prepared using four APIs with a range of aqueous solubility, i.e., acetaminophen (ACE), chlorpheniramine (CHL), ibuprofen (IBU), and pseudoephedrine hydrochloride (PSE). Two hydrophilic polymers, polyethylene oxide (PEO) and hydroxypropyl methylcellulose (HPMC) were selected and tested as primary matrix polymers for the formulations. It was found from the experiments that multiple regression model was capable of estimating drug dissolution for both PEO and HPMC matrix preparations. Based on major formulation factors the regression models provide satisfactory prediction of drug release, which could further aid in formulation development and optimization.

Hydrophilic polymers in a swellable matrix tablet hydrate quickly to form a hydrogel layer on the exterior of the dosage once in contact with water or biologic fluid. The resultant hydrogel serves as a barrier to regulate water permeation into the matrix and drug diffusion from the preparation. It is therefore important to understand how the polymer is hydrated and what mechanism exists between hydrogel formation and drug dissolution from a swellable matrix tablet. In this thesis, a TA texture analyzer was utilized to monitor and characterize matrix swelling properties during dissolution process. Multiple regression models were employed to analyze the quantitative relationship between drug dissolution or hydrogel thickness and major formulation factors (polymer ratio, drug solubility). Modified release matrix tablets were prepared using four APIs with a range of aqueous solubility, i.e., acetaminophen (ACE), chlorpheniramine (CHL), ibuprofen (IBU), and pseudoephedrine hydrochloride (PSE). Two hydrophilic polymers, polyethylene oxide (PEO) and hydroxypropyl methylcellulose (HPMC) were selected and tested as primary matrix polymers for the formulations. It was found from the experiments that multiple regression model was capable of estimating drug dissolution for both PEO and HPMC matrix preparations. Based on major formulation factors the regression models provide satisfactory prediction of drug release, which could further aid in formulation development and optimization.

Software developers often encapsulate reusable code as Application Programming Interfaces (APIs). The co-evolution of applications and APIs may motivate an API migration: the replacement of application dependencies to an original API by dependencies to an alternative API that provides similar functionality and abstractions. In this dissertation, we investigate issues associated with API migration in object-oriented systems, with special focus on wrapping approaches. We present two studies and a set of developer interviews that elicit issues in the process and techniques used in API migration in practice. The results suggest that the most pressing issues relate to discovery and specification of differences between APIs, and to assessment of migration correctness. This dissertation introduces techniques and a method to address these issues. We propose the use of design patterns to support the specification of API wrappers. API wrapping design patterns encode solutions to common wrapping design problems. We present an initial catalog of such patterns that were abstracted from programming idioms found in existing API wrappers. We introduce the concept of compliance testing for API migration, a form of automated testing. Compliance testing supports the discovery of behavioral differences between a wrapper and its corresponding original API, as well as assessment of wrapper correctness. Compliance testing uses API contracts and assertion tunings to explicitly capture and enforce the notion of a “good enough” wrapper that is informal in practice. We present the Koloo method for wrapper-based API migration. The method prescribes practical steps to use compliance testing as a means to elicit the requirements for the API migration, and to assess its correctness. Koloo fits within the iterative, sample-driven general API migration process usually followed by developers in practice. We evaluate the Koloo method in an empirical study. The subjects cover the domains of XML processing, GUI programming and bytecode engineering. The results provide evidence that Koloo is superior to alternative methods in driving the development of a wrapper that is tailored for the application under migration. The results also show that API contracts help driving the evolution of the wrapper, and assertion tuning is necessary to relax the semantics of strict equality contracts, and useful to compromise on features that are difficult to emulate perfectly. Finally, we validate that the proposed design patterns are used in practical wrappers.

Zugl.: Berlin, Techn. Universiẗat, Diss., 2008.

Techn. Universiẗat, Diss., 2003--Darmstadt.

Internet of Things blir allt mer vanligt i hemmet. På senare år har utbudet av uppkopplade enheter som hjälper till att automatisera delar av hemmet ökat. Uppkopplade sensorer är en del av detta och de erbjuder övervakning av till exempel temperatur, luftfuktighet, rörelse och ljus. Genom att presentera mätvärden från sensorer via ett grafiskt gränssnitt har man möjligheten att agera — manuellt eller automatiskt — på dessa värden för att till exempel justera temperatur i god tid. Målet med detta arbete är att utveckla en IoT-produkt som ett sensornätverk för övervakning av mätvärden från sensorer på enkortsdatorn Raspberry Pi. Syftet är att skapa ett skalbart system med en modulär design. Två Raspberry Pi användes för att utveckla ett IoT-system där en enhet läser in mätvärden från sensorer och en annan enhet exponerar ett REST API som möjliggör kommunikation via HTTP-protokollet för att skicka och ta in mätvärden. Mätvärden lagras i en databas och de senaste mätvärdena presenteras i ett grafiskt användargränssnitt. Resultatet är ett sensornätverk med en modulär design som kan användas för att övervaka senast uppmäta värden av temperatur och luftfuktighet i omgivningen. Dessa värden presenteras i ett grafiskt gränssnitt. / Internet of Things is becoming more common in the home. In recent years, the availability of connected devices that help automate parts of the home has increased. Connected sensors are part of this and they offer monitoring of, for example, temperature, humidity, motion and light. By presenting measurment values from sensors via a graphical interface, you have the option to act — manually or automatically – on these values, to for example, adjust the temperature in good time. The aim of this report is to develop an IoT product as a sensor network to collect data from sensors connected to the single board computer Raspberry Pi. The purpose is to create a scalable system with a modular design. Two Raspberry Pi were used to develop an IoT system where a device collects measu- rement values from sensors and another device which exposes a REST API that enables communication through the HTTP-protocol to send and recieve data. Measurment values are stored in a database and the latest measurement values are presented in a grahpical user interface. The result is a sensor network with a modular design that can be used to collect humi- dity and temperature values in the enviroment. These values are presented in a graphical user interface.