Use of neural networks in robot positioning of large flexible redundant manipulators

Deflection compensation of flexible boom structures in robot positioning is usually done using tables containing the magnitude of the deflection with inverse kinematics solutions of a rigid structure. The number of table values increases greatly if the working area of the boom is large and the required positioning accuracy is high. The inverse kinematics problems are very nonlinear, and if the structure is redundant, in some cases it cannot be solved in a closed form. If the structural flexibility of the manipulator arms is taken into account, the problem is almost impossible to solve using analytical methods. Neural networks offer a possibility to approximate any linear or nonlinear function. This study presents four different methods of using neural networks in the static deflection compensation and inverse kinematics solution of a flexible hydraulically driven manipulator. The training information required for training neural networks is obtained by employing a simulation model that includes elasticity characteristics. The functionality of the presented methods is tested based on the simulated and measured results of positioning accuracy. The simulated positioning accuracy is tested in 25 separate coordinate points. For each point, the positioning is tested with five different mass loads. The mean positioning error of a manipulator decreased from 31.9 mm to 4.1 mm in the test points. This accuracy enables the use of flexible manipulators in the positioning of larger objects. The measured positioning accuracy is tested in 9 separate points using three different mass loads. The mean positioning error decreased from 10.6 mm to 4.7 mm and the maximum error from 27.5 mm to 11.0 mm.

Platform as a Service - new opportunities for software development companies

Today cloud computing is the next stage in development information-oriented society in field of information technologies. Great attention is paid to cloud computing in general, but the lack of scientific consideration to components brings to the problem, that not all aspects are well examined. This thesis is an attempt to consider Platform as a Service (a technology of providing development environment through the Internet) from divergent angles. Technical characteristics, costs, time, estimation of effectiveness, risks, strategies that can be applied, migration process, advantages and disadvantages and the future of the approach are examined to get the overall picture of cloud platforms. During the work literature study was used to examine Platform as a Service, characteristics of existent cloud platforms were explored and a model of a typical software development company was developed to create a scenario of migration to cloud technologies. The research showed that besides all virtues in reducing costs and time, cloud platforms have some significant obstacles in adoption. Privacy, security and insufficient legislation impede the concept to be widespread.

Development of Calculation Procedures for Wastewater Treatment Technologies for a Training System

Efficient designs and operations of water and wastewater treatment systems are largely based on mathematical calculations. This even applies to training in the treatment systems. Therefore, it is necessary that calculation procedures are developed and computerised a priori for such applications to ensure effectiveness. This work was aimed at developing calculation procedures for gas stripping, depth filtration, ion exchange, chemical precipitation, and ozonation wastewater treatment technologies to include them in ED-WAVE, a portable computer based tool used in design, operations and training in wastewater treatment. The work involved a comprehensive online and offline study of research work and literature, and application of practical case studies to generate ED-WAVE compatible representations of the treatment technologies which were then uploaded into the tool.

Supermatrix-hankkeen vahvuudet, heikkoudet, mahdollisuudet ja uhat

Supermatrix on Finnet-liitto ry:n jäsenyritysten hanke, joka tuo nopeiden valokuituyhteyksien avulla erilaisia sähköisiä palveluita kuluttajien koteihin ja yritysten toimipisteisiin. Näitä palveluita ovat mm. virtualisoidut henkilö-kohtaiset tietokoneet, tiedon tallennuspalvelut ja multimediasisältö, kuten teräväpiirtotelevisio. Tässä diplomityössä arvioidaan Supermatrixin palveluiden toteutumis-mahdollisuuksia sekä teknologian, että markkinoiden kannalta. Työn tarkoituksena oli myös laskea virtualisoitujen tietokoneiden avulla tuotetun työpöytäpalvelun tuotantokustannus. Kustannuslaskentaa varten testattiin useiden valmistajien teknologioita, ja parhaimmista vaihtoehdoista laskettiin tuotantokustannukset. Tulevia Supermatrix-operaattoreita varten kehitettiin työkalu, jolla työpöytäpalvelun vaatimien investointien kannattavuus saadaan nopeasti selville. Tuotantohintojen laskelmat osoittavat, että työpöytäpalvelua on taloudelli-sesti mahdollista tuottaa luomaan lisäarvoa nopeille laajakaistayhteyksille. Yrityksissä työpöytien virtualisointi on jo tämän päivän teknologiaa, mutta kuluttaja-asiakkaiden innostuminen palvelusta vaatii uuden markkinan luomisen. Uhkana on, että kuluttajien ostokäyttäytymisen muuttaminen ei onnistu, koska Supermatrix ei tuota fyysisen tuotteen ostamisen tarjoamaa mielihyvää.

Verbal learning in mild cognitive impairment and alzheimer's disease : behavioural and neural approaches

The main focus of the present thesis was at verbal episodic memory processes that are particularly vulnerable to preclinical and clinical Alzheimer’s disease (AD). Here these processes were studied by a word learning paradigm, cutting across the domains of memory and language learning studies. Moreover, the differentiation between normal aging, mild cognitive impairment (MCI) and AD was studied by the cognitive screening test CERAD. In study I, the aim was to examine how patients with amnestic MCI differ from healthy controls in the different CERAD subtests. Also, the sensitivity and specificity of the CERAD screening test to MCI and AD was examined, as previous studies on the sensitivity and specificity of the CERAD have not included MCI patients. The results indicated that MCI is characterized by an encoding deficit, as shown by the overall worse performance on the CERAD Wordlist learning test compared with controls. As a screening test, CERAD was not very sensitive to MCI. In study II, verbal learning and forgetting in amnestic MCI, AD and healthy elderly controls was investigated with an experimental word learning paradigm, where names of 40 unfamiliar objects (mainly archaic tools) were trained with or without semantic support. The object names were trained during a 4-day long period and a follow-up was conducted one week, 4 weeks and 8 weeks after the training period. Manipulation of semantic support was included in the paradigm because it was hypothesized that semantic support might have some beneficial effects in the present learning task especially for the MCI group, as semantic memory is quite well preserved in MCI in contrast to episodic memory. We found that word learning was significantly impaired in MCI and AD patients, whereas forgetting patterns were similar across groups. Semantic support showed a beneficial effect on object name retrieval in the MCI group 8 weeks after training, indicating that the MCI patients’ preserved semantic memory abilities compensated for their impaired episodic memory. The MCI group performed equally well as the controls in the tasks tapping incidental learning and recognition memory, whereas the AD group showed impairment. Both the MCI and the AD group benefited less from phonological cueing than the controls. Our findings indicate that acquisition is compromised in both MCI and AD, whereas long13 term retention is not affected to the same extent. Incidental learning and recognition memory seem to be well preserved in MCI. In studies III and IV, the neural correlates of naming newly learned objects were examined in healthy elderly subjects and in amnestic MCI patients by means of positron emission tomography (PET) right after the training period. The naming of newly learned objects by healthy elderly subjects recruited a left-lateralized network, including frontotemporal regions and the cerebellum, which was more extensive than the one related to the naming of familiar objects (study III). Semantic support showed no effects on the PET results for the healthy subjects. The observed activation increases may reflect lexicalsemantic and lexical-phonological retrieval, as well as more general associative memory mechanisms. In study IV, compared to the controls, the MCI patients showed increased anterior cingulate activation when naming newly learned objects that had been learned without semantic support. This suggests a recruitment of additional executive and attentional resources in the MCI group.

Neural correlates of language learning in adults

The human language-learning ability persists throughout life, indicating considerable flexibility at the cognitive and neural level. This ability spans from expanding the vocabulary in the mother tongue to acquisition of a new language with its lexicon and grammar. The present thesis consists of five studies that tap both of these aspects of adult language learning by using magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) during language processing and language learning tasks. The thesis shows that learning novel phonological word forms, either in the native tongue or when exposed to a foreign phonology, activates the brain in similar ways. The results also show that novel native words readily become integrated in the mental lexicon. Several studies in the thesis highlight the left temporal cortex as an important brain region in learning and accessing phonological forms. Incidental learning of foreign phonological word forms was reflected in functionally distinct temporal lobe areas that, respectively, reflected short-term memory processes and more stable learning that persisted to the next day. In a study where explicitly trained items were tracked for ten months, it was found that enhanced naming-related temporal and frontal activation one week after learning was predictive of good long-term memory. The results suggest that memory maintenance is an active process that depends on mechanisms of reconsolidation, and that these process vary considerably between individuals. The thesis put special emphasis on studying language learning in the context of language production. The neural foundation of language production has been studied considerably less than that of perceptive language, especially on the sentence level. A well-known paradigm in language production studies is picture naming, also used as a clinical tool in neuropsychology. This thesis shows that accessing the meaning and phonological form of a depicted object are subserved by different neural implementations. Moreover, a comparison between action and object naming from identical images indicated that the grammatical class of the retrieved word (verb, noun) is less important than the visual content of the image. In the present thesis, the picture naming was further modified into a novel paradigm in order to probe sentence-level speech production in a newly learned miniature language. Neural activity related to grammatical processing did not differ between the novel language and the mother tongue, but stronger neural activation for the novel language was observed during the planning of the upcoming output, likely related to more demanding lexical retrieval and short-term memory. In sum, the thesis aimed at examining language learning by combining different linguistic domains, such as phonology, semantics, and grammar, in a dynamic description of language processing in the human brain.

Towards adoption of eLearning technologies at Lappeenranta University of Technology: Understanding Teachers‟ Adoption of Blackboard Learning System

The electronic learning has become crucial in higher education with increased usage of learning management systems as a key source of integration on distance learning. The objective of this study is to understand how university teachers are influenced to use and adopt web-based learning management systems. Blackboard, as one of the systems used internationally by various universities is applied as a case. Semi-structured interviews were made with professors and lecturers who are using Blackboard at Lappeenranta University of Technology. The data collected were categorized under constructs adapted from Unified Theory of Acceptance and Use of Technology (UTAUT) and interpretation and discussion were based on reviewed literature. The findings suggest that adoption of learning management systems by LUT teachers is highly influenced by perceived usefulness, facilitating conditions and gained experience. The findings also suggest that easiness of using the system and social influence appear as medium influence of adoption for teachers at LUT.

Notes on Emerging Technologies

This dissertation considers the impact of technology foresight in innovation within the context of a technology driven development. The main hypothesis made was that by using different methods of foresight in the industry level significant value could be created. The question was approached through a case study in portable fuel cell technology. The theoretical background of the study draws from Innovation, Product Development, Management of Technology, and Technology Foresight. The connection within the topics is made by analyzing foresight, not in a policy view as often done in Europe, but in a micro-level. Focusing mostly on how a technology driven development scenario could be analyzed. The study is based on a bibliometric, extrapolation and patent analysis within the context of a case study. In addition, a large two-year Delphi study was conducted. The study was finalized with a scenario work on the future possibilities of the case study technology. Original publications also consider several methodological issues. In the context of the case study, the study questions the practicality of establishing a portable fuel cell technology in Finland showing several impractical assumptions has been made. In a more conceptual level, the study makes notions on two underlying factors: policy-push technologies and growth of data. Policy-push questions in which level a policy effort towards a single technology is practical. The European foresight effort is more directed towards policy decisions in contrast to US foresight, which is to some extent corporate driven. Although the policy-based foresight has produced significant results in the European context, policy led efforts towards a single technology are challenging. Growth of data argues on the challenges produced by the large-scale application of quantitative measures of foresight. Bibliometric studies and trend extrapolations have been taken advantage of the increasing number of databases made available, and used these as the basis for forecasts. However, the relationship with actual development and quantitative evidence is still unproven.

Advanced welding technologies used for arctic metal structures

Rapid depletion of easy-to-access fossil fuel, predominantly, oil and gas resources has now necessitated increase in need to develop new oil and gas sources in ever more remote and hostile environments. This is necessary in order to explore more oil and gas resources to meet rapidly rising long-term energy demand in the world, both at present and in the nearest future. Arctic is one of these harsh environments, where enormous oil and gas resources are available, containing about 20% of the world total oil and gas, but the environmental conditions are very harsh and hostile. However, virtually all the facilities required for the exploration and development of this new energy source are constructed with metals as well as their alloys and are predominantly joined together by welding processes and technologies. Meanwhile, due to entirely different environment from the usual moderate temperate region, conventional welding technologies, common metals and their alloys cannot be applied as this Arctic environment demand metals structures with very high toughness and strength properties under extremely low temperature. This is due to the fact that metals transit from ductility to brittleness as the temperature moves toward extreme negative values. Hence, this research work investigates and presents the advanced welding technologies applicable to Arctic metal structures which can give satisfactory weldments under active Arctic service conditions. .

The challenges and success factors of commercializing cleaner technologies

Cleaner technologies include products, services, technologies, processes and systems that in use create less environmental hazard than the existing alternatives. Rapidly growing cleantech sector possesses an essential competitive advantage in the future. However, no profound research has been conducted on the characteristics of cleaner technologies and their effect on the commercialization process. This thesis aims at synthesizing scattered information and creating a basis for accelerating cleaner technology commercialization in Finnish context. Two research questions are defined: 1. What are the key challenges and success factors in the commercialization of cleaner technologies based on the existing literature? 2. What kind of lessons can be learned from the Finnish success stories of cleantech commercialization? The research was conducted as a literature review and supported with three case interviews. The results suggest that literature-based challenges are mostly related to, for example, difficulty in gathering customer information, unrealistic customer expectations, lack of resources, networks and proper success indicators, legislation, and unstructured strategy planning stemming from company culture. Handling the barriers require, above all, open communication from all stakeholders, management commitment and accurate goal setting, government-driven funding and incentives, and cooperation with educational facilities. Finnish success cases emphasize especially customer attention: listening to customers and receiving feedback from them during the whole commercialization process to correct the errors early and save resources, visionary in fulfilling customer needs, ability to question company’s own business performance, not being afraid of making mistakes but learning from them, and continuously observing and evaluating the commercialization process.

Near-Threshold Computing

Valmistustekniikoiden kehittyessä IC-piireille saadaan mahtumaan yhä enemmän transistoreja. Monimutkaisemmat piirit mahdollistavat suurempien laskutoimitusmäärien suorittamisen aikayksikössä. Piirien aktiivisuuden lisääntyessä myös niiden energiankulutus lisääntyy, ja tämä puolestaan lisää piirin lämmöntuotantoa. Liiallinen lämpö rajoittaa piirien toimintaa. Tämän takia tarvitaan tekniikoita, joilla piirien energiankulutusta saadaan pienennettyä. Uudeksi tutkimuskohteeksi ovat tulleet pienet laitteet, jotka seuraavat esimerkiksi ihmiskehon toimintaa, rakennuksia tai siltoja. Tällaisten laitteiden on oltava energiankulutukseltaan pieniä, jotta ne voivat toimia pitkiä aikoja ilman akkujen lataamista. Near-Threshold Computing on tekniikka, jolla pyritään pienentämään integroitujen piirien energiankulutusta. Periaatteena on käyttää piireillä pienempää käyttöjännitettä kuin piirivalmistaja on niille alunperin suunnitellut. Tämä hidastaa ja haittaa piirin toimintaa. Jos kuitenkin laitteen toiminnassa pystyään hyväksymään huonompi laskentateho ja pienentynyt toimintavarmuus, voidaan saavuttaa säästöä energiankulutuksessa. Tässä diplomityössä tarkastellaan Near-Threshold Computing -tekniikkaa eri näkökulmista: aluksi perustuen kirjallisuudesta löytyviin aikaisempiin tutkimuksiin, ja myöhemmin tutkimalla Near-Threshold Computing -tekniikan soveltamista kahden tapaustutkimuksen kautta. Tapaustutkimuksissa tarkastellaan FO4-invertteriä sekä 6T SRAM -solua piirisimulaatioiden avulla. Näiden komponenttien käyttäytymisen Near-Threshold Computing –jännitteillä voidaan tulkita antavan kattavan kuvan suuresta osasta tavanomaisen IC-piirin pinta-alaa ja energiankulusta. Tapaustutkimuksissa käytetään 130 nm teknologiaa, ja niissä mallinnetaan todellisia piirivalmistusprosessin tuotteita ajamalla useita Monte Carlo -simulaatioita. Tämä valmistuskustannuksiltaan huokea teknologia yhdistettynä Near-Threshold Computing -tekniikkaan mahdollistaa matalan energiankulutuksen piirien valmistaminen järkevään hintaan. Tämän diplomityön tulokset näyttävät, että Near-Threshold Computing pienentää piirien energiankulutusta merkittävästi. Toisaalta, piirien nopeus heikkenee, ja yleisesti käytetty 6T SRAM -muistisolu muuttuu epäluotettavaksi. Pidemmät polut logiikkapiireissä sekä transistorien kasvattaminen muistisoluissa osoitetaan tehokkaiksi vastatoimiksi Near- Threshold Computing -tekniikan huonoja puolia vastaan. Tulokset antavat perusteita matalan energiankulutuksen IC-piirien suunnittelussa sille, kannattaako käyttää normaalia käyttöjännitettä, vai laskea sitä, jolloin piirin hidastuminen ja epävarmempi käyttäytyminen pitää ottaa huomioon.

Neural mechanisms underlying conscious and unconscious vision. Evidence from event-related potentials and transcranial magnetic stimulation

Vision affords us with the ability to consciously see, and use this information in our behavior. While research has produced a detailed account of the function of the visual system, the neural processes that underlie conscious vision are still debated. One of the aims of the present thesis was to examine the time-course of the neuroelectrical processes that correlate with conscious vision. The second aim was to study the neural basis of unconscious vision, that is, situations where a stimulus that is not consciously perceived nevertheless influences behavior. According to current prevalent models of conscious vision, the activation of visual cortical areas is not, as such, sufficient for consciousness to emerge, although it might be sufficient for unconscious vision. Conscious vision is assumed to require reciprocal communication between cortical areas, but views differ substantially on the extent of this recurrent communication. Visual consciousness has been proposed to emerge from recurrent neural interactions within the visual system, while other models claim that more widespread cortical activation is needed for consciousness. Studies I-III compared models of conscious vision by studying event-related potentials (ERP). ERPs represent the brain’s average electrical response to stimulation. The results support the model that associates conscious vision with activity localized in the ventral visual cortex. The timing of this activity corresponds to an intermediate stage in visual processing. Earlier stages of visual processing may influence what becomes conscious, although these processes do not directly enable visual consciousness. Late processing stages, when more widespread cortical areas are activated, reflect the access to and manipulation of contents of consciousness. Studies IV and V concentrated on unconscious vision. By using transcranial magnetic stimulation (TMS) we show that when early visual cortical processing is disturbed so that subjects fail to consciously perceive visual stimuli, they may nevertheless guess (above chance-level) the location where the visual stimuli were presented. However, the results also suggest that in a similar situation, early visual cortex is necessary for both conscious and unconscious perception of chromatic information (i.e. color). Chromatic information that remains unconscious may influence behavioral responses when activity in visual cortex is not disturbed by TMS. Our results support the view that early stimulus-driven (feedforward) activation may be sufficient for unconscious processing. In conclusion, the results of this thesis support the view that conscious vision is enabled by a series of processing stages. The processes that most closely correlate with conscious vision take place in the ventral visual cortex ~200 ms after stimulus presentation, although preceding time-periods and contributions from other cortical areas such as the parietal cortex are also indispensable. Unconscious vision relies on intact early visual activation, although the location of visual stimulus may be unconsciously resolved even when activity in the early visual cortex is interfered with.