Tactile-Proprioceptive Robotic Grasping

Robotic grasping has been studied increasingly for a few decades. While progress has been made in this field, robotic hands are still nowhere near the capability of human hands. However, in the past few years, the increase in computational power and the availability of commercial tactile sensors have made it easier to develop techniques that exploit the feedback from the hand itself, the sense of touch. The focus of this thesis lies in the use of this sense. The work described in this thesis focuses on robotic grasping from two different viewpoints: robotic systems and data-driven grasping. The robotic systems viewpoint describes a complete architecture for the act of grasping and, to a lesser extent, more general manipulation. Two central claims that the architecture was designed for are hardware independence and the use of sensors during grasping. These properties enables the use of multiple different robotic platforms within the architecture. Secondly, new data-driven methods are proposed that can be incorporated into the grasping process. The first of these methods is a novel way of learning grasp stability from the tactile and haptic feedback of the hand instead of analytically solving the stability from a set of known contacts between the hand and the object. By learning from the data directly, there is no need to know the properties of the hand, such as kinematics, enabling the method to be utilized with complex hands. The second novel method, probabilistic grasping, combines the fields of tactile exploration and grasp planning. By employing well-known statistical methods and pre-existing knowledge of an object, object properties, such as pose, can be inferred with related uncertainty. This uncertainty is utilized by a grasp planning process which plans for stable grasps under the inferred uncertainty.

Kestävän kehityksen periaatteiden mukaisen liiketoiminnan vaikutus yrityksen kannattavuuteen

Tässä Pro Gradu -tutkielmassa tutkittiin kestävän kehityksen periaatteiden mukaisen liiketoiminnan vaikutusta yrityksen kannattavuuteen. Tutkimuksessa mukana olleet yritykset jaettiin neljään luokkaan kestävän kehityksen suorituskyvyn perusteella ja näiden luokkien välisiä kannattavuuseroja tarkasteltiin tilastollisia menetelmiä käyttäen. Tutkimuksen tulosten perusteella ei voida sanoa kestävän kehityksen mukaisen liiketoiminnan johtavan parempaan kannattavuuteen.

Ulkomaalaisen yrityksen verkostosuhteet Venäjällä

Tutkimuksen tavoitteena on konkreettisen yritysverkoston avulla selvittää, minkälaisia ovat ulkomaalaisen yrityksen potentiaaliset kumppanit ja yritysten väliset suhteet Venäjällä. Toisena tavoitteena on kuvata käytännön työelämään sopivalla menetelmällä riittävän kokonaisvaltaisesti yritysverkoston kumppanit sekä kumppaneiden ja kärkiyrityksen väliset suhteet. Samalla tarkastellaan yritysten välisten suhteiden riskejä. Selvitysmenetelmällä pyritään nopeuteen ja ketteryyteen ja sen tavoitteena on lisätä ulkomaisen johdon käsitystä yritysverkostosta johdon päätöksentekoa varten. Tutkimus jakaantuu teoria tarkasteluun ja yhden Venäjällä toimivan ulkomaisen yrityksen osto-osaston verkostoa selvittävään empiiriseen osaan. Teoriatarkastelussa selvitetään erilaisia lähestymistapoja ja laajempia viitekehyksiä yritysverkostojen tutkimukseen. Teoriatarkastelun perusteella valittiin viitekehykset yrityskumppaneiden ja yritysten välisen suhteen sekä riskien arviointiin. Empiirisen osan tutkimus toteutettiin haastattelukyselytutkimuksena perustuen näihin viitekehyksiin. Yrityskumppaneita ja yritysten välisiä suhteita tarkastellaan tilastollisin menetelmin ja riskejä arvioidaan laadullisella tutkimusotteella. Tutkimustulokset vastaavat monelta osin liiketoimintakulttuurista ja –ympäristöstä saatua kokemukseen ja tutkimustietoon perustuvaa käsitystä. Verkostoitumisen kulmakivet ovat hyvin toimivat ja määritellyt vaihdannan liiketoiminta- ja tukiprosessit, hyvin tunnetut kumppanit ja tälle perustalle rakennetut sosiaaliset suhteet sekä liiketoimintaympäristöön ja –kulttuuriin soveltuvat yhteistyökompetenssit. Tutkitun yritysverkoston yhteistyösuhteet voidaan jakaa hierarkkiseen organisaatiokumppanuuteen, toimittajakumppanuuteen, luottamukseen perustuvaan markkinaehtoiseen suhteeseen ja opportunistiseen markkinasuhteeseen. Hyviä yhteistyökumppaneita ja –suhteita löytyy taustaltaan erilaisista toimittajista. Tutkimuksessa käytetyt viitekehykset toimivat hyvin erityisesti yrityskumppanin arvioinnissa. Yritysten välisen suhteen arviointiin käytetyn viitekehyksen ongelmat liittyivät lähinnä erilaiseen liiketoimintakulttuuriin ja käsitykseen yritysten välisestä strategisesta suhteesta. Riskit liittyivät toimitussuhteeseen useammin kuin omaan organisaatioon tai toimittajaan.

Applications of Industrial Statistics

This dissertation examines knowledge and industrial knowledge creation processes. It looks at the way knowledge is created in industrial processes based on data, which is transformed into information and finally into knowledge. In the context of this dissertation the main tool for industrial knowledge creation are different statistical methods. This dissertation strives to define industrial statistics. This is done using an expert opinion survey, which was sent to a number of industrial statisticians. The survey was conducted to create a definition for this field of applied statistics and to demonstrate the wide applicability of statistical methods to industrial problems. In this part of the dissertation, traditional methods of industrial statistics are introduced. As industrial statistics are the main tool for knowledge creation, the basics of statistical decision making and statistical modeling are also included. The widely known Data Information Knowledge Wisdom (DIKW) hierarchy serves as a theoretical background for this dissertation. The way that data is transformed into information, information into knowledge and knowledge finally into wisdom is used as a theoretical frame of reference. Some scholars have, however, criticized the DIKW model. Based on these different perceptions of the knowledge creation process, a new knowledge creation process, based on statistical methods is proposed. In the context of this dissertation, the data is a source of knowledge in industrial processes. Because of this, the mathematical categorization of data into continuous and discrete types is explained. Different methods for gathering data from processes are clarified as well. There are two methods for data gathering in this dissertation: survey methods and measurements. The enclosed publications provide an example of the wide applicability of statistical methods in industry. In these publications data is gathered using surveys and measurements. Enclosed publications have been chosen so that in each publication, different statistical methods are employed in analyzing of data. There are some similarities between the analysis methods used in the publications, but mainly different methods are used. Based on this dissertation the use of statistical methods for industrial knowledge creation is strongly recommended. With statistical methods it is possible to handle large datasets and different types of statistical analysis results can easily be transformed into knowledge.

GIS assessing traditional and modern agricultural land use/land cover change. A case study 1959-2005: Rekijoki, Somero, SW-Finland

Finland’s rural landscape has gone through remarkable changes from the 1950’s, due to agricultural developments. Changed farming practices have influenced especially traditional landscape management, and modifications in the arable land structure and grasslands transitions are notable. The review of the previous studies reveal the importance of the rural landscape composition and structure to species and landscape diversity, whereas including the relevance in presence of the open ditches, size of the field and meadow patches, topology of the natural and agricultural landscape. This land-change study includes applying remote sensed data from two time series and empirical geospatial analysis in Geographic Information Systems (GIS). The aims of this retrospective research is to detect agricultural landscape use and land cover change (LULCC) dynamics and discuss the consequences of agricultural intensification to landscape structure covering from the aspects of landscape ecology. Measurements of LULC are derived directly from pre-processed aerial images by a variety of analytical procedures, including statistical methods and image interpretation. The methodological challenges are confronted in the process of landscape classification and combining change detection approaches with landscape indices. Particular importance is paid on detecting agricultural landscape features at a small scale, demanding comprehensive understanding of such agroecosystems. Topological properties of the classified arable land and valley are determined in order to provide insight and emphasize the aspect the field edges in the agricultural landscape as important habitat. Change detection dynamics are presented with change matrix and additional calculations of gain, loss, swap, net change, change rate and tendencies are made. Transition’s possibility is computed following Markov’s probability model and presented with matrix, as well. Thesis’s spatial aspect is revealed with illustrative maps providing knowledge of location of the classified landscape categories and location of the dynamics of the changes occurred. It was assured that in Rekijoki valley’s landscape, remarkable changes in landscape has occurred. Landscape diversity has been strongly influenced by modern agricultural landscape change, as NP of open ditches has decreased and the MPS of the arable plot has decreased. Overall change in the diversity of the landscape is determined with the decrease of SHDI. Valley landscape considered as traditional land use area has experienced major transitional changes, as meadows class has lost almost one third of the area due to afforestation. Also, remarkable transitions have occurred from forest to meadow and arable land to built area. Boundaries measurement between modern and traditional landscape has indicated noticeable proportional increase in arable land-forest edge type and decrease in arable land-meadow edge type. Probability calculations predict higher future changes for traditional landscape, but also for arable land turning into built area.

Young Registered Nurses’ Intent to Leave the Profession in Finland - A Mixed-Method Study

The purpose of this study was to examine and expand understanding concerning young Finnish registered nurses (RN) with an intention to leave the profession and the related variables, specifically when that intention has emerged before the age of 30. The overall goal of the study was to develop a conceptual model in relation to young RNs’ intention to leave the profession. Suggestions for policymakers, nurse leaders and nurse managers are presented for how to retain more young RNs in the nursing workforce. Suggestions for future nursing research are also provided. Phase I consists of two sequential integrative literature reviews of 75 empirical articles concerning nurses’ intention to leave the profession. In phase II, data had been collected as part of the Nurses’ Early Exit (NEXT) study, using the BQ-12 structured postal questionnaire. A total of 147 young RNs participated in the study. The data were analysed with statistical methods. In phase III, firstly, an in-depth interpretive case study was conducted in order to understand how young RNs explain and make sense of their intention to leave the profession. The data in this study consisted of longitudinal career stories by three young RNs. The data was analysed by using narrative holistic-content and thematic methods. Secondly, a total of 15 young RNs were interviewed in order to explore in-depth their experiences concerning organizational turnover and their intent to leave the profession. The data was analysed using conventional content analysis. Based on earlier research, empirical research on the young RNs intention to leave the profession is scarce. Nurses’ intention to leave the profession has mainly been studied with quantitative descriptive studies, conducted with survey questionnaires. Furthermore, the quality of previous studies varies considerably. Moreover, nurses’ intention to leave the profession seems to be driven by a number of variables. According to the survey study, 26% of young RNs had often considered giving up nursing completely and starting a different kind of job during the course of the previous year. Many different variables were associated with an intention to leave the profession (e.g. personal burnout, job dissatisfaction). According to the in-depth inquiries, poor nursing practice environments and a nursing career as a ‘second-best’ or serendipitous career choice were themes associated with young RNs’ intention to leave the profession. In summary, young RNs intention to leave the profession is a complex phenomenon with multiple associated variables. These findings suggest that policymakers, nurse leaders and nurse managers should enable improvements in nursing practice environments in order to retain more young RNs. These improvements can include, for example, adequate staffing levels, balanced nursing workloads, measures to reduce work-related stress as well as possibilities for advancement and development. Young RNs’ requirements to provide high-quality and ethical nursing care must be recognized in society and health-care organizations. Moreover, sufficient mentoring and orientation programmes should be provided for all graduate RNs. Future research is needed into whether the motive for choosing a nursing career affects the length of the tenure in the profession. Both quantitative and in-depth research is needed for the comprehensive development of nursing-turnover research.

Managing Customer Issues through a Support Channel Network

The importance of after-sales service or service in general can be seen and experienced by customers every day with industrial as well as other non-industrial services or products. This dissertation, drawing on theory and experience, focuses on practical engineering implications, specifically the management of customer issues in the after-sales phase in the mobile phone arena. The main objective of this doctoral dissertation is to investigate customer after-sales issue management, specifically regarding mobile phones. The case studies focus on issue resolution time and the issue of corrective actions. This dissertation consists of a main body and four peer-reviewed journal articles and one manuscript currently under review by a peer-reviewed journal. The main body of this dissertation examines the elements of customer satisfaction, loyalty, and retention with respect to corrective actions to address customer issues and issue resolution time through literature and empirical studies. The five independent works are case studies supporting the thesis research questions. This study examines four questions: 1) What are the factors affecting corrective actions for customers? 2) How can customer issue resolution time be controlled? 3) What are the factors affecting processes in the service chain? and 4) How can communication be measured in a service chain? In this work, both quantitative and qualitative analysis methods are used. The main body of the thesis reviews the literature regarding the elements that bridge the five case studies. The case studies of the articles and surveys lean more toward the methodology of critical positivism and then apply the interpretive approach in interpreting the results. The case study articles employ various statistical methods to analyze and to interpret the empirical and survey data. The statistical methods were used to create a model that is useful for significantly optimizing issue resolution time. Moreover, it was found that samples for verifying issues provided by the customer neither improve the perceived quality of corrective actions nor the perceived quality of issue resolution time. The term “service” in this work is limited to the technical services that are provided by product manufacturers and after-sales authorized service vendors. On the basis of this research work, it has been observed that corrective actions and issue resolution time are associated with customer satisfaction and hence, according to induction theory, to customer loyalty and retention. This thesis utilizes knowledge of marketing and customer relationships to contribute to the existing body of knowledge concerning information and communication technology for after-sales service recovery of mobile terminals. The established models in the thesis contribute to the existing knowledge of the after-sales process of dealing with customer issues in the field of mobile phones. The findings suggest that process managers could focus more on communication and training provided to the staff as new technology evolves rapidly. The study also suggest the managers formulate strategies for how customers can be kept informed on a regular basis of the status of issues that have been escalated for corrective action. The findings also lay the foundation for the comprehensive objective to control the entire product development process, starting with conceptualization. This implies that robust design should be applied to the new products so that problems affecting customer service quality are not repeated. The objective will be achieved when the entire service chain from product development to the final user can be modeled and this model can be used to support the organization at all levels.

Histopathological diagnosis of intra- and extrahepatic neonatal cholestasis

The histopathology of the liver is fundamental for the differential diagnosis between intra- and extrahepatic causes of neonatal cholestasis. However, histopathological findings may overlap and there is disagreement among authors concerning those which could discriminate between intra- and extrahepatic cholestasis. Forty-six liver biopsies (35 wedge biopsies and 11 percutaneous biopsies) and one specimen from a postmortem examination, all from patients hospitalized for neonatal cholestasis in the Pediatrics Service of Hospital de Clínicas de Porto Alegre, were prospectively studied using a specially designed histopathological protocol. At least 4 of 5 different stains were used, and 46 hepatic histopathological variables related to the differential diagnosis of neonatal cholestasis were studied. The findings were scored for severity on a scale from 0 to 4. Sections which showed less than 3 portal spaces were excluded from the study. Sections were examined by a pathologist who was unaware of the final diagnosis of each case. Bile tract permeability was defined by scintigraphy of the bile ducts and operative cholangiography. The F test and discriminant analysis were used as statistical methods for the study of the hepatic histopathological variables. The chi-square method with Yates correction was used to relate the age of the patients on the date of the histopathological study to the discriminatory variables between intra- and extrahepatic cholestasis selected by the discriminant function test. The most valuable hepatic histopathological variables for the discrimination between intra- and extrahepatic cholestasis, in decreasing order of importance, were periportal ductal proliferation, portal ductal proliferation, portal expansion, cholestasis in neoductules, foci of myeloid metaplasia, and portal-portal bridges. The only variable which pointed to the diagnosis of intrahepatic cholestasis was myeloid metaplasia. Due to the small number of patients who were younger than 60 days on the date of the histopathological study (N = 6), no variable discriminated between intra- and extrahepatic cholestasis before the age of 2 months and all of them, except for the portal expansion, were discriminatory after this age. In infants with cholestasis, foci of myeloid metaplasia, whenever present in the liver biopsy, suggested intrahepatic cholestasis. Periportal ductal proliferation, portal ductal proliferation, portal expansion, cholestasis in neoductules, portal cholestasis and portal-portal bridges suggested extrahepatic obstructive cholestasis.

Quality of radiotherapy care by development of e-feedback knowledge

The aim of this three phase study was to develop quality of radiotherapy care by the e-Feedback knowledge of radiotherapy -intervention (e-Re-Know). In Phase I, the purpose was to describe the quality of radiotherapy care and its deficits experienced by cancer patients. Based on the deficits in patient education in Phase II, the purpose was to describe cancer patients’ e-knowledge expectations in radiotherapy. In Phase III, the purpose was to develop and evaluate the outcomes of the e-Re-Know among breast cancer patients. The ultimate aim was to develop radiotherapy care to support patients’ empowerment with patient e-education. In Phase I (2004-2005), the descriptive design was used, and 134 radiotherapy patients evaluated their experiences by Good Nursing Care Scale for Patients (GNCS-P) in the middle of RT period. In Phase II (2006-2008), the descriptive longitudinal design was used and 100 radiotherapy patients’ e-knowledge expectations of RT were evaluated using open-ended questionnaire developed for this study before commencing first RT, in the middle of the treatment, and concluding RT period. In Phase III, firstly (2009-2010), the e-Re-Know intervention, i.e. knowledge test and feedback, was developed in terms of empowering knowledge and implemented with e-feedback approach based on literature and expert reviews. Secondly (2011-2014), the randomized controlled study was used to evaluate the e-Re-Know. Breast cancer patients randomized to either the intervention group (n=65) receiving the e-Re-Know by e-mail before commencing first RT and standard education or the control group (n=63) receiving standard education. The data were collected before commencing first RT, concluding last RT and 3 months after last RT using RT Knowledge Test, Spielberger’s State Trait Inventory (STAI) and Functional Assessment of Cancer Therapy - Breast (FACT-B) –instruments. Data were analyzed using statistical methods and content analysis. The study showed radiotherapy patients experienced quality of care high. However, there were deficits in patient education. Furthermore, radiotherapy patients’ multidimensional e-knowledge expectations through Internet covered mainly bio-physiological and functional knowledge. Thus, the e-Re-Know was developed and evaluated. The study showed when breast cancer patients’ carried out the e-Re-Know their knowledge of side effects self-care was significantly increased and quality of life (QOL) significantly improved in line with decrease in anxiety from time before radiotherapy period to three months after. In addition, the e-Re-Know has potential to have positive effects on anxiety and QOL, regardless of patient characteristics or knowledge level. The results support the theory of empowering patient education suggesting that empowerment can be supported by confirming patients’ understanding of own knowledge level. In summary, the e-Feedback knowledge of radiotherapy (e-Re-Know) intervention can be recommended in development of quality of radiotherapy care experienced by breast cancer patients. Further research is needed to assess and develop patient-centred quality of care by patient education among cancer patients.

VVER-440 Thermal Hydraulics as a Computer Code Validation Challenge

This thesis concentrates on the validation of a generic thermal hydraulic computer code TRACE under the challenges of the VVER-440 reactor type. The code capability to model the VVER-440 geometry and thermal hydraulic phenomena specific to this reactor design has been examined and demonstrated acceptable. The main challenge in VVER-440 thermal hydraulics appeared in the modelling of the horizontal steam generator. The major challenge here is not in the code physics or numerics but in the formulation of a representative nodalization structure. Another VVER-440 specialty, the hot leg loop seals, challenges the system codes functionally in general, but proved readily representable. Computer code models have to be validated against experiments to achieve confidence in code models. When new computer code is to be used for nuclear power plant safety analysis, it must first be validated against a large variety of different experiments. The validation process has to cover both the code itself and the code input. Uncertainties of different nature are identified in the different phases of the validation procedure and can even be quantified. This thesis presents a novel approach to the input model validation and uncertainty evaluation in the different stages of the computer code validation procedure. This thesis also demonstrates that in the safety analysis, there are inevitably significant uncertainties that are not statistically quantifiable; they need to be and can be addressed by other, less simplistic means, ultimately relying on the competence of the analysts and the capability of the community to support the experimental verification of analytical assumptions. This method completes essentially the commonly used uncertainty assessment methods, which are usually conducted using only statistical methods.

Peruskoulun yläkouluvalinnat Turussa. Perheiden yläkouluvalintojen rakentuminen äitien puheissa ja toimissa

Tutkimuksessa tarkastellaan peruskoulun yläkouluvalintoja Turussa. Tarkastelun keskiössä ovat vuonna 1997 syntyneiden turkulaislasten vanhempien yläkouluvalintaa koskeva yleinen sekä omaan lapseen kiinnittyvä puhe ja toimijuus paikallisessa institutionaalisessa kouluvalintatilassa sekä vanhempien lapsen koulutukseen ja kouluvalintaan liittämät perustelut, merkitykset, arvot ja arvostukset. Tämän lisäksi tutkimuksessa tarkastellaan puheesta ja toimista rakentuvia perheiden kouluvalintastrategioita, joita peilataan äitien koulutuksellisiin ja sosiaalisiin resursseihin sekä paikalliseen toimintapolitiikkaan. Tutkimus ei kerro ainoastaan paikallisessa kontekstissa tapahtuvista kouluvalinnoista, vaan laajemmin yhteiskunnassa vallitsevista hierarkioista ja arvoista sekä koulutukseen ja sosioekonomiseen asemaan linkittyvistä normatiivisista toimintatavoista. Tutkimuksessa käytetään haastattelu- ja kyselyaineistoja. Aineistot kerättiin osana kahta laajempaa Suomen Akatemian rahoittamaa Helsingin ja Turun yliopistojen kanssa yhteistyössä tehtyä tutkimusprojektia Vanhemmat ja kouluvalinta – Perheiden koulutusstrategiat, eriarvoistuminen ja paikalliset koulupolitiikat suomalaisessa peruskoulussa (VAKOVA) 2009–2012 sekä Parents and School Choice. Family Strategies, Segregation and School Policies in Chilean and Finnish Basic Schooling (PASC) 2010–2013. Tutkimusaineistot koostuvat 87 turkulaisäidin haastattelusta ja kyselyaineistosta. Kyselyaineiston analyysissä on käytetty kuvailevia tilastollisia menetelmiä, ja sitä käytetään ensisijaisesti taustoittamaan haastatteluaineistoa. Haastatteluaineiston analyysi perustuu pääasiallisesti teema-analyysiin, mutta toimija-asema-analyysin osalta myös diskursiiviseen lähestymistapaan. Haastatteluaineiston pohjalta esiin nousseiden lasten koulutusta ja kouluvalintoja koskevien kuvausten perusteella perheiden yläkouluvalinnat jaettiin kolmeen erityyppiseen valintastrategiaan: perinteiseen lähikouluvalintastrategiaan (n=41), ambivalenttiseen kouluvalintastrategiaan (n=23) ja päämäärätietoiseen kouluvalintastrategiaan (n=23). Jokainen kolmesta strategiasta piti sisällään kahdenlaista toimijuutta kouluvalintakentällä. Ryhmittely kouluvalintastrategioittain ja toimija-asemittain perustui äitien puhetapaan kouluvalinnoista ja yleisemmin koulutukseen liitetyistä merkityksistä ja arvoista sekä konkreettiseen toimintaan kouluvalinnan suhteen. Lähikouluvalintastrategiaa suosivien jälkeläiset siirtyivät koulunsa yleisluokalle. Perheet toimivat valintakentällä kaupungin rajaavan toimintapolitiikan ohjaamina, jolloin kouluvalinta näytti passiiviselta. Osoitteenmukaiseen kouluun siirtymistä perusteltiin praktisilla syillä; koulumatkan pituudella, kulkuyhteyksillä ja lapsen kaverisuhteilla. Hyvinvointivaltion edellytykseksi nähtiin kaikille taattu samanvertainen koulutus ja edelleen luotettiin perinteistä peruskoulua määrittävään mahdollisuuksien tasa-arvoon. Koulutuksen yhdeksi tärkeäksi tehtäväksi nähtiin lapsen kasvattaminen hyvinvoivaksi ja onnelliseksi. Vanhempien toiminta oli perinteisen kouluvalintastrategian mukaista. Ambivalenttista kouluvalintastrategiaa käyttävistä perheistä toiminta kouluvalintakentällä oli kahtalaista. Äidit joko harkitsivat kouluvalintoja tai vertailivat kouluja ja niihin pääsymahdollisuuksia realistisesti tasapainoillen ohjaavan ja mahdollistavan toimintapolitiikan välimaastossa. Tärkeintä oli olla tietoinen kaupungin kouluvalintapolitiikasta sekä siitä, että valinnoilla voi olla merkitystä jälkikasvun koulupolulle. Eri vaihtoehtojen punnitsemisen jälkeen päädyttiin useimmin lähikoulun painotettuun opetukseen. Lapsen peruskoulutusta haluttiin rikastaa painotetulla opetuksella ja hänen toivottiin pääsevän motivoituneeseen ja oppimismyönteiseen koululuokkaan. Valintoja tehtiin paikallisen toimintapolitiikan puitteissa lapsen parasta toivoen. Koulutuksen tehtäväksi nähtiin lapsen intellektuaalinen kasvu kiedottuna koulutuksen tuottamaan hyvinvointiin ja onnellisuuteen. Perheiden valintastrategiaksi muodostui ambivalenttinen strategia motivoituneen oppimisympäristön löytämiseksi. Päämäärätietoista kouluvalintastrategiaa käyttävät vanhemmat hyödynsivät aktiivisesti erilaisia reittejä tiettyihin yläkouluihin pääsemiseksi. Ennakoivien perheiden lapset olivat opiskelleet sellaisessa alakoulussa, joka ei kuulunut yläkoulun oppilasalueelle, mutta takasi lapselle reitin suosittuun yläkouluun. Määrätietoisten perheissä havahduttiin valintoihin puolestaan yläkouluun siirryttäessä, jolloin koulupaikkaa haettiin sopivimman painotetun opetuksen ja koulun maineen mukaan pois lähiyläkoulusta. Lähikoulu -periaate koettiin epäoikeudenmukaiseksi, sillä lapsella tulee olla oikeus toteuttaa omia kykyjään ja lahjakkuuttaan valikoidussa oppilasryhmässä ja perheillä mahdollisuus valita lapsen koulu. Paikallinen toimintapolitiikka ei näyttänyt rajaavan vanhempien kouluvalintoja. Koulutuksen tarkoitukseksi nähtiin intellektuaalinen kasvu ja akateemissivistävä tehtävä. Päämäärätietoisen kouluvalintavalintastrategian tavoitteena oli perheelle sopivan habituksen takaaminen. Paikallinen toimintapolitiikka mahdollisti vanhempien erilaisten kouluvalintastrategioiden rakentumisen ohjaten ensisijaisesti lähiyläkouluun, mutta samalla mahdollistaen koulun valinnan toissijaisen haun kriteerein. Kouluvalintastrategioihin ja toimintatapaan kouluvalintakentällä kytkeytyi vanhempien koulutukseen liittämät arvot sekä kulttuuriset ja sosiaaliset resurssit ja se, miten niitä käytettiin.

Accuracy improvement of a demand forecasting model

This research concerns different statistical methods that assist to increase the demand forecasting accuracy of company X’s forecasting model. Current forecasting process was analyzed in details. As a result, graphical scheme of logical algorithm was developed. Based on the analysis of the algorithm and forecasting errors, all the potential directions for model future improvements in context of its accuracy were gathered into the complete list. Three improvement directions were chosen for further practical research, on their basis, three test models were created and verified. Novelty of this work lies in the methodological approach of the original analysis of the model, which identified its critical points, as well as the uniqueness of the developed test models. Results of the study formed the basis of the grant of the Government of St. Petersburg.

Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37) on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively). Three cells (4.5%) were bistratified, having thick dendrites, and the others (95.5%) were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40%) and 2 groups with inner (50-100%) stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

Manual and semi-automatic quantification of in vivo ¹H-MRS data for the classification of human primary brain tumors

In vivo proton magnetic resonance spectroscopy (¹H-MRS) is a technique capable of assessing biochemical content and pathways in normal and pathological tissue. In the brain, ¹H-MRS complements the information given by magnetic resonance images. The main goal of the present study was to assess the accuracy of ¹H-MRS for the classification of brain tumors in a pilot study comparing results obtained by manual and semi-automatic quantification of metabolites. In vivo single-voxel ¹H-MRS was performed in 24 control subjects and 26 patients with brain neoplasms that included meningiomas, high-grade neuroglial tumors and pilocytic astrocytomas. Seven metabolite groups (lactate, lipids, N-acetyl-aspartate, glutamate and glutamine group, total creatine, total choline, myo-inositol) were evaluated in all spectra by two methods: a manual one consisting of integration of manually defined peak areas, and the advanced method for accurate, robust and efficient spectral fitting (AMARES), a semi-automatic quantification method implemented in the jMRUI software. Statistical methods included discriminant analysis and the leave-one-out cross-validation method. Both manual and semi-automatic analyses detected differences in metabolite content between tumor groups and controls (P < 0.005). The classification accuracy obtained with the manual method was 75% for high-grade neuroglial tumors, 55% for meningiomas and 56% for pilocytic astrocytomas, while for the semi-automatic method it was 78, 70, and 98%, respectively. Both methods classified all control subjects correctly. The study demonstrated that ¹H-MRS accurately differentiated normal from tumoral brain tissue and confirmed the superiority of the semi-automatic quantification method.

Reference value of brachial-ankle pulse wave velocity for the eastern Chinese population and potential influencing factors

The present study was conducted to obtain reference values for brachial-ankle pulse wave velocity (baPWV) and to evaluate influencing factors of baPWV according to gender. Using automatic devices, baPWV was measured simultaneously in 2095 subjects. A total of 647 healthy subjects, none of whom presented atherosclerotic risk factors, were analyzed in the present study. Two different statistical methods were used to obtain reference values for baPWV according to subject gender and age. The association between baPWV value and gender, as well as other features, were analyzed. For male subjects, multiple stepwise analysis showed that age, systolic blood pressure (SBP), heart rate (HR), and plasma levels of triglycerides (TG) were independent predictors of baPWV. For female subjects, age, SBP, HR, and plasma levels of uric acid (UA) were independent predictors of baPWV. In male subjects, the upper limits of baPWV values were 1497.43/1425.00, 1518.67/1513.25, 1715.97/1726.50, 1925.20/1971.90, and 2310.18/2115.00 cm/s, obtained using two different statistical methods for the age ranges of 30-39, 40-49, 50-59, 60-69, and 70 and older, respectively. For females, the upper limits of baPWV values were 1426.70/1411.13, 1559.15/1498.95, 1733.50/1739.00, 1958.63/1973.78, and 2720.80/2577.00 cm/s for the age ranges of 30-39, 40-49, 50-59, 60-69, and 70 and older, respectively. Aging is the most important influencing factor for baPWV value and its effect is more prominent in females. The reference values of baPWV according to age and gender may be useful for the clinical diagnosis and preventive therapy of cardiovascular diseases.