Browsing by study line "Ohjelmistojärjestelmät"

In the world of constantly growing data masses the efficient extraction, saving and accessing that data for business intelligence and analytics has become increasingly important to businesses. Analytics and business intelligence software is offered by many providers in the market for all sizes of organizations and there are multiple ways to build an analytics system, or pipeline from scratch or integrated with tools available on the market. In this case study we explore and re-design the analytics pipeline solution of a medium sized software product company by utilizing the design science research methodology. We discuss the current technologies and tools on the market for business intelligence and analytics and consider how they fit into our case study context. As design science suggests, we design, implement and evaluate two prototypes of an analyt- ics pipeline with an Extract, Transform and Load (ETL) solution and data warehouse. The prototypes represent two different approaches to building an analytics pipeline - an in-house approach, and a partially outsourced approach. Our study brings out typical challenges similar businesses may face when designing and building their own business intelligence and analytics software. In our case we lean towards an analytics pipeline with an outsourced ETL process to be able to pass various different types of event data with a consistent data schema into our data warehouse with minimal maintenance work. However, we also show the value of near real time analytics with an in-house solution, and offer some ideas on how such a pipeline may be built.

Modularity is often used to manage the complexity of monolithic software systems. This is done through reducing maintenance costs by minimizing the entanglement in software code and functionality. Modularity also lowers future development costs through enabling the reuse and stacking of different types of modular functionality and software code for different environments and software engineering problems. Although there are important differences between the problem solving processes and practices of machine learning system developers and software engineering developers, machine learning system developers have been shown to be able to adopt a lot from traditional software engineering. A systematic literature review is used to identify 484 studies published in four electronic sources from January 1990 to October 2021. After examination of papers, statistical and qualitative results are formed for selected 86 studies which provide sufficient information regarding the presence of modular operators and comparison to monolithic solutions. The selected studies addressed a wide number of different tasks and domains, which saw performance benefits compared to monolithic machine learning and deep learning methods. Nearly two thirds of studies discovered Modular Neural Networks (MNNs) providing improvements in task accuracy when compared to monolithic solutions. Only 16,3\% of studies reported efficiency values in their comparisons. Over 82,5\% of studies that reported their MNNs efficiency found benefits in computation time, memory/size and energy consumption when compared to monolithic solutions. The majority of studies were carried out in laboratory environments on singular focused tasks and static requirements, which may have limited the visibility of modular operators. MNNs show positive promise for performance and efficiency in machine learning. More comparable studies are needed, especially from the industry, that use MMNs in constantly changing requirements and thus apply multiple modular operators.

Chatbotteja on kehitetty jo vuosikymmenten ajan, mutta nykyinen kiinnostus on kasvanut niihin teknologian kehityksen myötä. Chatbotit palvelevat ihmisiä eri tarkoituksissa ja niiden toiminta perustuu keskusteluun ihmisen kanssa. Chatbotit tarjoavat henkilökohtaista palvelua vuorokauden jokaisena hetkenä, jonka vuoksi niiden tarve on lisääntynyt monilla aloilla, kuten verkkomyynnissä ja terveydenhuollossa. Chatbottien kehityksessä on tärkeää pohtia niiden toteutusta. Monet käyttäjät suosivat edelleen muita informaationlähteitä heidän ongelmiensa ratkaisuun. Yksi tapa mitata chatbot-järjestelmien laatua on tutkia niiden käyttäjäkokemusta. Tässä tutkielmassa tarkastellaan empiirisesti chatbot-sovellusten käyttäjäkokemusta. Empiirisen osion muodostaa laadullinen tutkimus, jonka avulla pyritään vastaamaan seuraavaan tutkimuskysymykseen: Kuinka chatbottien käyttäjäkokemusta voitaisiin parantaa? Tutkimus järjestettiin Osaamisbotti-palvelun kanssa, joka tarjosi testiympäristön tutkimuksen suorittamiselle. Tutkimukseen osallistui kahdeksan henkilöä, jotka suorittivat heille annetun tehtävän keskustelemalla chatbotin kanssa. Tutkimuksen aineisto on saatu protokolla-analyysin ja sen jälkeisen haastattelun keinoin. Tulokset esittävät, että ihmismäiset keskustelukyvyt, pidemmät vastaukset sekä tehokas keskustelun kulku parantavat chatbottien käyttäjäkokemusta. Lisäksi riittävällä informoinnilla ohjataan keskustelua sekä vältetään virhetilanteita. Chatbottien hyvällä saatavuudella sekä helppokäyttöisyydellä kasvatetaan niiden hyväksyntää ja käyttöönottoa. Tutkielman tuloksia voidaan hyödyntää tulevissa tutkimuksissa ja chatbottien kehitystyössä.

Background. In API requests to a confidential data system, there always are sets of rules that the users must follow to retrieve desired data within their granted permission. These rules are made to assure the security of the system and limit all possible violations. Objective. The thesis is about detecting the violations of these rules in such systems. For any violation found, the request is considered as containing inconsistency and it must be fixed before retrieving any data. This thesis also looks for all diagnoses of inconsistencies requests. These diagnoses promote reconstructing the requests to remove any inconsistency. Method. In this thesis, we choose the design science research methodology to work on solutions. In this methodology, the current problem in distributing data from a smart building plays as the main motivation. Then, system design and development are implemented to prove the found solutions of practicality, while a testing system is built to confirm its validity. Results. The inconsistencies detection is considered as a diagnostic problem, and many algorithms have been found to resolve the diagnostic problem for decades. The algorithms are developed based on DAG algorithms and preserved to apply on different purposes. This thesis is based on these algorithms and constraint programming techniques to resolve the facing issues of the given confidential data system. Conclusions. A combination of constraint programming techniques and DAG algorithms for diagnostic problems can be used to resolve inconsistencies detection in API requests. Despite the need on performance improvement in application of these algorithms, the combination works effectively, and can resolve the research problem.

User-centered design (UCD) and agile software development (ASDP) both answer separate answers for issues modern software development projects face, but no direct guidelines on how to implement both in one project exist. Relevant literature offers multiple separate detailed techniques, but the applicability of the techniques is dependant on multiple features of the development team, e.g., personnel and expertise available and the size of the team. In this thesis, we propose a new agile development process model, which is created through evaluating the existing UCD–ASDP combination methods suggested in current literature to find the most suitable application methods to the case this study is applied to. In this new method, the development team is taken to do their daily work physically near to the software’s end- users for a short period of time to make the software team as easily accessible as possible. This method is then applied within an ongoing software project for a two week period in which the team visits two separate locations where end-users have the possibility to meet the development team. This introduced "touring" method ended up offering the development team a valuable under-standing of the skill and involvement level of the end-users they met without causing significant harm to the developer experience. The end-users were pleased with the visits and the method gained support and suggestions for future applications.

In recent years, virtual reality devices have entered the mainstream with many gaming-oriented consumer devices. However, the locomotion methods utilized in virtual reality games are yet to gain a standardized form, and different types of games have different requirements for locomotion to optimize player experience. In this thesis, we compare some popular and some uncommon locomotion methods in different game scenarios. We consider their strengths and weaknesses in these scenarios from a game design perspective. We also create suggestions on which kind of locomotion methods would be optimal for different game types. We conducted an experiment with ten participants, seven locomotion methods and five virtual environments to gauge how the locomotion methods compare against each other, utilizing game scenarios requiring timing and precision. Our experiment, while small in scope, produced results we could use to construct useful guidelines for selecting locomotion methods for a virtual reality game. We found that the arm swinger was a favourite for situations where precision and timing was required. Touchpad locomotion was also considered one of the best for its intuitiveness and ease of use. Teleportation is a safe choice for games not requiring a strong feeling of presence.

Software testing is an important process when ensuring a program's quality. However, testing has not traditionally been a very substantial part of computer science education. Some attempts to integrate it into the curriculum has been made but best practices still prove to be an open question. This thesis discusses multiple attempts of teaching software testing during the years. It also introduces CrowdSorcerer, a system for gathering programming assignments with tests from students. It has been used in introductory programming courses in University of Helsinki. To study if the students benefit from creating assignments with CrowdSorcerer, we analysed the number of assignments and tests they created and if they correlate with their performance in a testing-related question in the course exam. We also gathered feedback from the students on their experiences from using CrowdSorcerer. Looking at the results, it seems that more research on how to teach testing would be beneficial. Improving CrowdSorcerer would also be a good idea.

A US government agency estimated the national cost of inadequate software testing to be \$60 billion annually, and that was 20 years ago. As the role of technology and software has been rapidly increasing worldwide for decades, it suffices to say that the worldwide fiscal effect of poor testing practices today is probably ``quite a bit``. An increasing number of industry-focused survey studies on testing have been published worldwide in recent years, signalling an increased need to characterize the testing practices of the software development industry. These types of studies can help to guide future research efforts towards subjects that are meaningful to the industry, and provide practitioners with an opportunity to compare their own practice to those of their peers and recognize the main improvement areas. As no secondary study devoted to these types of survey studies could be identified, the opportunity was seized to carry out a literature review was to find out what the data from these studies can tell us when aggregated. The precise topics focused on were the usage of test levels, test types, test design techniques, test tools and test automation. Looking at these studies in aggregate tells us about some general trends: unit testing, functional testing and regression testing are popular everywhere, and also quite popular regardless of the surveyed population are performance testing and usability testing. The popularity of the other test levels and test types vary from survey to survey or region to region. Black-box techniques and experience-based techniques are more popular than white-box techniques. Exploratory testing, error guessing, use case testing and boundary value analysis are some of the most popular test design techniques. Much of the industry relies on manual testing over automated testing and/or have inadequately adopted the usage of testing tools.

Itseohjautuvien autojen kehittyessä niiltä oletetaan turvallisempaa liikennekäyttäytymistä kuin ihmiskuskeilta. Itseohjautuva järjestelmä voi käsitellä tietoa nopeammin kuin ihminen, mutta kun vastassa on onnettomuustilanteiden aiheuttamat moraaliset ongelmat, ei oikeudenmukaisesti toimivaa järjestelmää ole helppo rakentaa. Moraaliset ongelmat nousevat varsin tärkeäksi kysymykseksi tilanteessa, jossa itseohjautuvan auton tulee päättää mitä tehdä onnettomuuden sattuessa. Kun kyseessä on hengenvaarallinen tilanne, on vaikea ohjelmoida miten auton tulisi toimia. Samoja ongelmia on pohdittu moraalikonekokeen ja ADC-mallin kautta, jonka myötä käyttäjät on laitettu vastaamaan miten itseohjautuvan auton tulisi toimia ongelmatilanteessa. Vastauksia analysoimalla voidaan päätellä, miten inhimillisen moraalikäsittelyn ja intuition voisi ohjelmoida itseohjautuvalle autolle. Moraaliongelmien lisäksi itseohjautuvassa järjestelmässä löytyy myös teknologisia puutteita, esimerkiksi miten auton ympärillä olevaa ympäristöä pystytään mallintamaan hankalissa sääolosuhteissa, kuten sumussa tai sateessa. Lisäksi itseohjautuvaa teknologiaa kohtaan on huomattu selkeää käyttäjävastarintaa ja ennakkoluuloja, jotka vaikuttavat uuden teknologian käyttöönotossa. Silti itseohjautuvat järjestelmät ovat kehittyneet paljon viimeisen 20 vuoden sisällä ja monet autonvalmistajat ja tutkimuskeskukset ovat valmiita keksimään ratkaisuja näihin haasteisiin ja kehittämään urbaaneissa olosuhteissa toimivan ja moraalisesti oikein toimivan itseohjautuvan auton.

Micro frontend -arkkitehtuuri on mikropalveluarkkitehtuurin erikoistapaus, jossa mikropalveluiden rooliin kuuluu tuottaa datan lisäksi myös käyttöliittymä toimintoineen. Toistaiseksi tästä arkkitehtuurimallista on julkaistu kirjallisuutta varsin vähän ja esitetyt mallit ovat enimmäkseen prototyyppitoteutuksia. Tässä tutkielmassa tarkastellaan erään tietyn ohjelmistoprojektin tuloksena syntynyttä micro frontend -ratkaisua design science -kehyksessä. Aluksi kuvataan toimintaympäristö, ongelmat ja sieltä nousevat vaatimukset. Tähän esitetään Web Components -teknologiaan perustuva ratkaisu, jonka kelpoisuutta arvioidaan sekä sen tuotantokäytöstä saatujen kokemusten perusteella että ATAM-evaluointimenetelmää käyttäen. Saadut tulokset osoittavat muun muassa sen, että edellä mainittu Web Components -teknologia mahdollistaa HTML-standardin määrittelemien ohjelmointirajapintojen suoran ja tehokkaan käytön web-kehityksessä — ilman tarvetta ohjelmistokehyksille. Lisäksi kyseenalaistetaan näkemys, jonka mukaan micro frontend -arkkitehtuurin kehitys olisi järkevää vain organisatorisista syistä: sille voi olla myös vahvat perustelut esimerkiksi ohjelmiston muokattavuudelle asetettujen vaatimusten vuoksi, ja se on mahdollista toteuttaa myös pienen kehittäjäryhmän toimesta.