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Trendit poistavan fluktuaatioanalyysin edistyneet menetelmät ja niiden sovellukset laskennallisessa kardiologiassa
Get PDFFractals are ubiquitous in nature. A defining characteristic of fractality is self-similarity; the phenomenon looks similar when observed at multiple scales, which implies the existence of a power law scaling relation. Detrended fluctuation analysis (DFA) is a popular tool for studying these fractal scaling relations. Power laws become linear relationships in logarithmic scales, and conventionally these scaling exponents are determined by simple linear regression in approximately linear regions in doubly logarithmic plots. However, in practice the scaling is hardly ever exact, and its behavior may often vary at different scales.
This thesis extends the fluctuation analysis by introducing robust tools for determining these scaling exponents. A method based on the Kalman smoother is utilized for extracting a whole spectrum of exponents as a function of the scale. The method is parameter-free and resistant to statistical noise, which distinguishes it from prior efforts for determining such local scale exponents. Additionally, an optimization scheme is presented to obtain data-adaptive segmentation of approximately linear regimes. Based on integer linear programming model, the procedure may readily be customized for various purposes. This versatility is demonstrated by applying the method to a group of data to find a common segmentation that is particularly well-suited for machine learning applications.
First, the methods are are employed in exploring the details of the scaling by analyzing simulated data with known scaling properties. These findings provide insight into the interpretation of earlier results.
Second, the methods are applied to the study of heart rate variability. The beating of the heart follows fractal-like patterns, and deviations in these complex variations may be indicative of cardiac diseases. In this context DFA is traditionally performed by extracting two scaling exponents, for short- and long-range correlations, respectively. This has been criticized as an oversimplification, which is corroborated by the results of this thesis. The heart rate exhibits richer fractal-like variability, which becomes apparent in the full scaling spectra. The additional information provided by these methods facilitate improved classification of cardiac conditions.Fraktaaleja esiintyy kaikkialla luonnossa. Fraktaalisuuden ominaispiirre on itsesimilaarisuus, eli ilmiö näyttää samankaltaiselta, kun sitä tarkastellaan useassa eri skaalassa. Tämä johtaa siihen, että ilmiön skaalautuvuus noudattaa potenssilakia. Tällaisia fraktaalisia skaalausrelaatioita voidaan tutkia trendit poistavan fluktuaatioanalyysin avulla (Detrended Fluctuation Analysis, DFA). Logaritminen skaala muuntaa potenssilait lineaarisiksi riippuvuuksiksi, ja tavallisesti skaalauseksponentit määritetään logaritmisista kuvaajista lineaarisen regression avulla. Kuitenkaan skaalautuvuus ei lähes koskaan ole täydellistä, ja se voi myös muuttua eri skaaloilla.
Tämä työ laajentaa fluktuaatioanalyysia esittelemällä paranneltuja menetelmiä näiden skaalauseksponenttien määrittämiseen. Kokonainen spektri skaalauseksponentteja skaalan funktiona määritetään hyödyntämällä Kalman-suodinta. Tämän menetelmän etuja verrattuna aikaisempiin tapoihin määrittää paikallisia skaalauseksponentteja ovat sen parametrivapaa esitys ja vakaus myös kohinaisissa tapauksissa. Lisäksi esitetään lineaariseen kokonaislukuoptimointiin perustuva menetelmä, jonka avulla skaalautuvuudessa voidaan erottaa alueita, jotka noudattavat likimäärin potenssilakia. Tämän mallin muokkaaminen eri tarpeisiin on myös suoraviivaista. Mallia sovelletaan yhteisen segmentaation etsimiseksi datajoukolle, mikä on tarpeen erityisesti koneoppimisen menetelmiä varten.
Esitettyjen menetelmien avulla tutkitaan ensin simuloituja prosesseja, joiden teoreettinen skaalautuminen tunnetaan. Menetelmien mahdollistama yksityiskohtainen analyysi selittää aikaisempia havaintoja DFA:n käyttäytymisessä.
Menetelmiä sovelletaan myös sykevälivaihtelun fraktaalianalyysiin. Terveen sydämen sykeväleissä on fraktaalisia piirteitä, joita eri sairaudet muokkaavat ja hävittävät. Sykevälivaihtelun fraktaalisuutta on perinteisesti kuvattu lyhyen- ja pitkän kantaman skaalauseksponenteilla. Tätä kahden eksponentin mallia on kritisoitu riittämättömäksi, ja tämän työn tulokset vahvistavat tätä näkökulmaa. Skaalauseksponenttispektri paljastaa, että sykevälivaihtelun fraktaalisuus on kahden eksponentin mallia monimuotoisempaa. Esitetyillä menetelmillä saatava lisäinformaatio mahdollistaa aikaisempaa tarkemman sydänsairauksien luokittelun
Performance modeling and prototyping of directional radio link for moving machines
No full textUsage of smart devices and the amount of mobile data traffic have grown exponentially in the past decade. Also, novel applications have specific bandwidth and latency requirements. All of these combined are calling for a new networking technology. Upcoming 5G wireless networks aim to answer the current and potential future needs of wireless technology. In the context of the implementation and development challenges, we can highlight two important use cases of 5G: Enhanced Mobile Broadband, which promises high data rate with low latency during rush hour, and Machine-Type-Communication, where wireless devices can communicate with each other in a fully automated manner with no need for human interaction. Concerning the first use case, this work has focused on evaluating the core performance metrics, including throughput and Signal-to-Interference plus Noise Ratio (SINR), of suggested radio technology for 5G (mmWave) in a dense urban deployment. In this work, additional Unmanned Aerial Vehicle (UAV)-assisted Access Points (APs) are considered to provide extra coverage. For this reason, a number of appropriate scenarios were simulated and evaluated using NS-3 platform. Regarding the second use case, this work has focused on enabling high-speed long-range communication specifically used in autonomous robotic off-shore operations and modeling the performance of such systems in terms of throughput and Received Signal Strength (RSS). For this purpose, a system of directional radio links utilizing IEEE 802.11 Wi-Fi and 3GPP LTE was designed, installed and tested on an autonomous boat to enable a high-speed bi-directional connection. This thesis describes the details of these research directions along with obtained results
Hinnoitteluprosessi globaaliin toimintaympäristöön
No full textMany companies operate in an increasing number of very diverse markets where the complexities of the B2B markets are further enhanced by the international operating environment. Simultaneously, as international involvement increases so does operational diversity within the companies. Together these result in prices that vary. As the internet allows customers to compare prices with ease, inconsistencies can cause significant harm. Unfortunately, academic research lacks descriptions of good pricing practices for the global operating environment, and where such exists, theory is far from the reality of companies.
This thesis examined the global pricing of a medium sized Finnish company with the aim of identifying biggest challenges in current prices and developing a more cohesive approach for the company’s global pricing. This research combined inductive and deductive research approaches by collecting interview data first, due to limited prior knowledge on the subject, and then utilizing existing literature in theory building. Both qualitative and quantitative methods where used to generate data and hence the researched uses mixed methods.
The study revealed that achieving more global pricing in the case company would require first addressing the issues in the current pricing. For each step of the global pricing process the characteristics of the global operating environment highlighted in the approach were dis-cussed in reference to the case company and the following challenges where identified: the role of strategy requires clarification and should be connected to pricing, common pricing priorities need to be developed, segmentation could be improved, there are too many prizing methods utilized to align with pricing capabilities and lack of clear pricing polices combined with large number of products makes implementation and control of prices difficult
Lessons learned for collission avoidance of robotic cars from aviation Airborne/Traffic Collision Avoidance Systems ACAS/TCAS
No full textTämä työ on tehty Liikenteen turvallisuusvirasto Trafissa osana sähkötekniikan diplomi-insinöörin tutkintoa. Diplomityön tarkoituksena oli tutkia, onko toisen liikennemuodon periaatteellisesti samantyyppisistä järjestelmistä ja niiden kehityksestä opittavaa siten, että myöhemmin kehitettävässä tekniikassa saavutettaisiin nopeammin ja siten ehkä edullisemminkin korkea turvallisuustaso. Ilmailussa on ollut ilma-alusten nopeuden vuoksi pidempään tarve erilaisille turvatekniikoille ja törmäyksenehkäisyille. Tieliikenteen nähtävissä oleva automatisoituminen tuo samat haasteet autoille. Kummassakin liikennemuodossa virheet näkyvät henkilöonnettomuuksina eli ovat hyvin sensitiivinen aihe, joten jo pienilläkin opinkappaleilla turvallisuuden parantumiseen voi olla suuret inhimilliset vaikutukset sekä ratkaiseva askel uuden tekniikan yleiseen hyväksyttävyyteen.
Ennakkokäsityksestä (teesi) poiketen tärkeimmäksi havainnoksi eivät nousseet sittenkään tekniset ratkaisut, vaan tarve selkeyttää UNECE:n rooli ja resurssit uusien järjestelmien kehittämisessä. Samalla sen suurempi medianäkyvyys järjestelmien esittelijänä tukisi kuljettajien ymmärrystä niiden toiminnasta ja rajoitteista.
Toinen oleellinen havainto oli, että korkean tason automaattiajamisen tasoilla on runsaasti mahdollisuuksia hyödyntää ilmailun kokemuksista. Toisaalta tieliikenteessä on paljon haasteita, joihin ilmailussa ei ole tarvinnut vastata.
Teknisiä näkökulmia oli useita. Robottiautoilun hyväksyttävyyden ja niiden yleistymisen keskeisin ominaisuus on turvallisuus. Järjestelmissä vikaan varautuminen voi edellyttää, että rinnakkain on käytössä jopa kolme erillistä järjestelmää tai järjestelmän osaa, jotta viallinen tulos voidaan ”äänestää” pois. Toisekseen eri automaatiotasoisten ajoneuvojen liikkuminen samassa ympäristössä vaatii poliittista periaateratkaisua; rakennetaanko tai rajataanko robottiautoille oma suljettu liikenneinfransa vai kulkevatko ne muun liikenteen seassa?
Nopeasti robottiajoneuvolta ihmiselle siirtyvien yllätystilanteiden hallinnan varalle pitää olla selkeät ja usein toistetut toimintamenetelmät. Parametrien tallennin ja niissä olevien tietojen analysointi onnettomuuksien jälkeen voi ehkäistä joko toimintatavoista tai teknisistä järjestelmistä johtuneiden onnettomuuksien toistumisen. Suojaavaksi tarkoitettu laitekin voi aiheuttaa alkuperäistä vakavampia uhkia, jos uhkia ei suunnitteluvaiheessa ole osattu huolellisella riskianalyysillä tunnistaa.The work presented in this thesis has been carried out at the Finnish Transport Safety Agency (Trafi) as part of a master’s degree in electrical engineering. This thesis examines whether similar systems created for one traffic form can be utilised in the development of technology for another traffic form so that a high level of safety could be reached faster and perhaps more economically. In aviation, different types of safety technology and collision avoidance systems have been necessary for a long time because of the high speed of aircraft. The automation of road transport is creating similar challenges for cars. In both traffic forms, errors may cause accidents involving persons. Thus, the topic is highly sensitive, and even the smallest lessons learned may have a major human impact and may constitute a decisive step towards the general acceptance of new technology.
Contrary to the hypothesis, the key findings did not concern technical solutions but the role and human resources of UNECE when new inventions are developed. Also UNECE’s more prominent existence on media by demonstrating these new inventions would support the drivers to understand systems’ capability and limitations.
The second essential finding was that in case of high level automated driving systems there are lots of opportunities to take advantage of experiences gained in aviation. Contrary to that, on road transport there are many challenges that needed not to be solved in aviation.
The topic has been examined from multiple technical viewpoints. Safety plays a key role in the acceptability and wider uptake of robotic cars. At system level, preparing for defects may require the simultaneous use of up to three different systems so that incorrect results can be “voted out”. Moreover, the movement of vehicles with different levels of automation in the same environment requires political decisions on whether to create a separate and closed transport infrastructure for robotic cars or allow them among other vehicles.
In surprising events, control transfers quickly from the robotic vehicle to the driver. The successful handling of these situations requires clear and frequently repeated operating methods. Using parameter recorders and analysing their data after accidents may prevent the reoccurrence of accidents caused by operating methods or technical systems
Transforming normal web-application into progressive web-application and the transformations effect on user experience
No full textTässä työssä kuvataan olemassa olevan Angular-web-sovelluksen muuttaminen progressiiviseksi web-sovellukseksi ja tähän muutokseen kuuluvat vaiheet. Lisäksi työssä vertaillaan progressiivisen web-sovelluksen ja normaalin web-sovelluksen käyttökokemusta.
Progressiivinen web-sovellus pyrkii tekemään web-sovelluksesta mahdollisimman natiivin web-sovelluksen (Android, iOS) kaltaisen. Normaalin web-sovelluksen muuttaminen progressiiviseksi web-sovellukseksi vaatii muutosten tekemistä ja lisäkirjastojen asentamista sovellukseen. Tässä työssä käydään läpi nämä askeleet, joita muutokseen tarvitaan Angular-sovelluksen osalta.
Lisäksi työssä vertaillaan normaalin web-sovelluksen ja progressiivisen web-sovelluksen käyttökokemusta empiirisesti sekä toteuttamalla mittauksia. Työssä tutkitaan minkälainen vaikutus progressiivisella toteutuksella on sovelluksen tehokkuuteen ja sitä kautta käyttökokemukseen. Työssä hyödynnetään olemassa olevaa Angular-sovellusta, joka muutetaan progressiiviseksi, ja vertaillaan näin syntyvää progressiivista Angular-sovellusta ja alkuperäistä Angular-sovellusta.
Lopuksi tehdään yhteenveto tuloksista ja pohditaan progressiivisen web-sovelluksen hyötyjä ja progressiivisen toteutuksen kannattavuutta eri tyyppisille sovelluksille. Progressiivisen web-teknologian avulla saavutetaan huomattava parannus sovelluksen käyttökokemukseen ja progressiivinen toteutus suoriutuu sovelluksille toteutettavista testeistä huomattavasti paremmin
Performance assessment of Narrowband IoT for Intelligent Cargo Transportation
Get PDFNarrow Band Internet of Things (NB-IoT) is the most advanced technology standard for short message services, such as sensor data, developed by 3GPP Release 13 and beyond. The NB-IoT is deployed over Long Term Evolution (LTE) Advanced Pro infrastructure and theoretically, it offers extended coverage up to 40 km from the base station. The objective of this thesis is to analyze the performance of NB-IoT technology in cargo shipment tracking using LTE cellular networks across the coastal line. Currently, about fifty thousand cargo ships use onboard Satellite communication system for all sorts of information exchange with the onshore data centers. The Satellite communication will continue to exist, even after deployment of NB-IoT.
Apart from the machine critical data of the cargo ships, the non-emergency periodic short messages for polling meteorological and container metadata such as temperature, humidity, gaseous detection, etc. will be crucial for the quality of the shipment and the traceability. In this thesis, we analyze deployment of NB-IoT sensors for cargo container to track and provide metadata about the condition of goods. We evaluate three implementation methods of NB-IoT for cargo ships, optimize the coverage and enhance the battery life of the sensor equipment. The main idea is to offload non-critical information that would otherwise use expensive Satellite links, thus embrace the NB-IoT technology at offshore and reduce the financial stress on the cargo shipments.
In the first method, all the sensors transfer the periodic data directly to the coastal LTE network when the ships sail in close proximity to the shore. In the second method, the sensors transfer data to an LTE base station installed locally on the ship and then accumulated information will be relayed to onshore LTE network over NB-IoT channel. In the third method, an Unmanned Aerial Vehicle (UAV/ Drone) base station will collect the data from the onboard sensors; it then relays the information to the onshore LTE network. For all methods, when there is no LTE coverage, the accumulated data will be sent over the Satellite link, which will be available onboard.
The assessment confirms the hypothesis that the packet loss probability reduces when the base station is located close to the sensor, where the number of retransmissions will be reduced, and more uplink resources will be available. For direct access scenario, a large number of users contend for Random Access Channel (RACH) simultaneously after entering into the LTE coverage. The packet will be dropped after reaching the maximum number of attempts for the RACH resources. As per the simulated results, mean lifespan of a sensor is greatly affected by the LTE network availability and random access procedure, during which the sensor spends most of the energy for transmissions. The mean transmit delay will be higher with second and third methods where the ship BS, UAV BS accumulate packets until they find the LTE network or relays the data to the Satellite link if the LTE outage is longer. This performance assessment provides technical insights for the maritime industry to embrace the NB-IoT for tracking and condition monitoring of shipment
Should-Cost Analysis as an Alternative to Open Book Accounti
Get PDFA key question that decision makers from start-ups to SMEs and corporates face is “to outsource, or not to outsource?”. In today’s business world which is fast-paced, the pressure on companies to provide products and services is higher than ever. To respond to this pressure but holding costs down, all types of companies need to outsource their non-core processes and more concentrate on their key core competencies. Nevertheless, the gained advantages of outsourcing can be beyond only cutting costs. Hence, it is critical to understand the different benefits for both company and its partners. Sharing information and supply chain collaboration have become the main elements of their success. Suppliers’ pricing decisions historically may have been in mystery and the details of a price are confidential. It is logical for a buyer to want to probe the main cost drivers. A recommended approach is to persuade the supplier to open its books. Some believe open book accounting (OBA) as a solution to that and it can deliver, but not guarantees, considerable results or cost savings.
The objective of this study is to find an alternative to OBA when the business partners are not ready or willing to open their books. The study shows OBA may not succeed even in mature and rather partnership-oriented relationships. Therefore, should-cost analysis supports the purchaser to achieve its aims to control the profits and costs made within upstream of supply chain. The study shows such alternative to OBA enables the purchaser to enhance the supply network’s efficiency by bringing the cost transparency into the customer-supplier relationships. This study illustrates should-cost analysis is an effective tool in determining fair and reasonable pricing and today it has to be embedded in procurement processes. Should-cost analysis determines what a product should cost on the basis of labor, materials, overhead, and profit margin
Tuote masterdatan hallinnan prosessin kehittäminen
No full textMaster data has caused issues in organizations for decades. Previously these have been addressed through new IS acquisitions. However, data is still not paid enough attention to, so the issues have continued. MDM was created to solve these problems.
Master data is the most business-critical data an organization has, and it consists of e.g. customer, product and vendor data. Due to the business-critical nature of master data, its management should be paid special attention to in organizations.
In the case organization of this study, the main issues related to master data are that the MDM processes and the data owners have not yet been defined. As found in the literature, an MDM initiative should always be started from one master data type. In this case, product master data was chosen.
Through this study two MDM processes could be created and additionally, a tentative model for the data and process ownership was formed. In the end, this research yielded two main findings: the created models are not the ultimate solution to the challenges in the case organization and the overall issues in product management might be causing many of the issues related to product master data
Asuntomarkkinat kehittyvässä kasvukeskuksessa
Get PDFKaupungistuminen on globaali trendi, joka vaikuttaa kaikkialla maailmassa. Kaupungistuminen tuo mukanaan monia hyötyjä ja toisaalta ongelmia, joilla on suoria ja epäsuoria vaikutuksia yhteiskunnalliseen ja alueelliseen kehitykseen. Tämän kandidaatintyön tavoitteena oli selvittää, mitä kaupungistuminen tarkoittaa ja miten kaupungistuminen vaikuttaa asuntomarkkinoihin Suomessa.
Ensimmäisessä luvussa määritellään, mitä kaupungistuminen tarkoittaa. Toisessa luvussa määritellään kaupungistumista aiheuttavia tekijöitä, kuten demograafiset tekijät, keskittyneisyys ja kasautuminen sekä saavutettavuus. Tämän jälkeen keskitytään tarkastelemaan kaupungistumisen piirteitä eli kaupunkirakenteen kehittymistä. Kolmannessa luvussa tutkitaan kaupungistumista Suomessa. Neljännessä luvussa tutkitaan, miten kaupungistuminen vaikuttaa asuntomarkkinoihin ja millä tavalla kaupungistuminen on vaikuttanut pääkaupunkiseudun asuntomarkkinoihin. Tämän jälkeen tutkitaan mitä haasteita kaupungistuminen tuo asuntomarkkinoille. Viides luku on yhteenveto, jossa käydään läpi tutkimuksen tulokset ja jatkotutkimusmahdollisuudet.
Tämä tutkimus osoittaa, että lisääntynyt muuttoliike on yksi tärkeimmistä kaupungistu-mista aiheuttava sekä suoraan asuntomarkkinoihin vaikuttava tekijä. Muuttoliike lisää kysyntää asuntomarkkinoilla, mikä vaikuttaa asuntojen hintoihin. Asuntotuotannon joustavuus vaikuttaa suoraan asuntojen hintoihin kysynnän ja tarjonnan kautta. Asunto-tuotannon jäykkyys ja lisääntynyt asuntojen kysyntä nostavat asuntojen hintoja. Sitä vastoin, asuntotuotannon joustavuus tasapainottaa asuntojen kysyntää ja tarjontaa, mikä hillitsee asuntojen hintojen nousua. Tutkimuksesta selviää myöskin, että muuttoliikkeellä on ollut monia vaikutuksia Helsingin seudun asuntomarkkinoihin. Muuttoliike lisäsi kerrostalojen rakentamista ja vapaarahoitteisten vuokra-asuntojen osuutta, pysäytti asumisväljyyden kasvun sekä nosti asuntojen hintoja
Can Blockchain Technology Facilitate Unbundling of Higher Education
Get PDFIn spite of the technological advancements we are surrounded with on a daily basis, the current higher education ecosystem is still lagging behind in terms of innovation and continues to function in a tightly bundled operation. Educational experts have stressed upon the need for reforming the higher education system in order to better fulfil the needs of its main consumer: the student. Unbundling aspects of higher education has been recognized as one such idea that can possibly result in universities reinventing themselves for the benefit of all stakeholders involved. At the same time, researchers have singled out blockchain technology as an emerging technology that has the potential of reforming current social systems. The launch of the EU Blockchain Observatory in February 2018 is one of the major indications that reflect the nature of interest in the potential of blockchain. Due to its capability to break the existing barriers of a trust less society and to provide a decentralized, transparent and secure method of handling any kind of transactions, blockchain technology could be used to unbundle aspects of higher education. There is a noticeable lack of empirical research when it comes to the use of blockchain technology in the higher education sector, specifically related to unbundling.
The main goal of this research is to understand if blockchain has the capability of facilitating unbundling of the higher education sector. In order to get a holistic view of the current ecosystem, a literature review was conducted regarding the problems surrounding the current higher education system along with the possibility of an unbundled education system in solving those problems. The literature review further included an analysis of blockchain as a technology and the current practical applications in the higher education already in motion in different parts of the world. Subsequently, semi-structured interviews were conducted with experts in the field of higher education as well as blockchain technology. The literature review and the results of the data analysis shed light on how unbundling should be brought about in the higher education sector. Adoption barriers with reference to blockchain technology in the context of unbundling higher education were revealed and discussed. As a result of this study, it was concluded that unbundling could possibly be instrumental in solving the numerous problems plaguing the higher educator sector today however, there has to be a balance between the traditional mode of education and the new modular amendments that are made in the process of unbundling. The capability of blockchain technology was identified as being just right to facilitate the unbundling of higher education. However, a number of technological, cultural and political and regulatory barriers were identified that could prevent the adoption of a blockchain based solution for higher education