Deposition and characterization of lines printed through laser-induced forward transfer

The possibility of printing two-dimensional micropatterns of biomolecule solutions is of great interest in many fields of research in biomedicine, from cell-growth and development studies to the investigation of the mechanisms of communication between cells. Although laser-induced forward transfer (LIFT) has been extensively used to print micrometric droplets of biological solutions, the fabrication of complex patterns depends on the feasibility of the technique to print micron-sized lines of aqueous solutions. In this study we investigate such a possibility through the analysis of the influence of droplet spacing of a water and glycerol solution on the morphology of the features printed by LIFT. We prove that it is indeed possible to print long and uniform continuous lines by controlling the overlap between adjacent droplets. We show how, depending on droplet spacing, several printed morphologies are generated, and we offer, in addition, a simple explanation of the observed behavior based on the jetting dynamics characteristic of the LIFT of liquids.

Urapolut ja niihin vaikuttavat tekijät S-ryhmässä

Urateoriat ovat murroksessa, kun urat ovat muuttumassa perinteisistä urapoluista rajattomiin, monisuuntaisiin uriin. Samaan aikaan erilaisten trainee-ohjelmien määrä lisääntyy vauhdilla. Urapolkujen tutkiminen on tästä syystä erittäin ajankohtaista. Tämän tutkielman tarkoituksena on tutkia, miten S-ryhmässä työskentelevien kaupallisen kenttäkoulutuksen käyneiden ja sen käymättömien urapolut eroavat toisistaan. Viimeaikaisten teorioiden mukaan urat voidaan jakaa objektiivisiin ja subjektiivisiin uriin sekä perinteisiin ja rajattomiin uriin. Aikaisempien tutkimustulosten pohjalta tarkastellaan yksilöiden uravalintoja ja käsityksiä hyvästä urasta. Myös yksilön sosiaalistuminen organisaatioon vaikuttaa sitoutumiseen ja tätä kautta uraan. Tutkimuksessa on käytetty kvalitatiivisia menetelmiä ja havaintoaineisto on kerätty sähköpostikyselyiden avulla S-ryhmässä työskenteleviltä henkilöiltä. Tutkimustulokset osoittavat, että urapolut ovat erilaisia. Kaikki tutkimukseen osallistuneet kenttäkoulutetut ovat johtaja-asemassa, vertailuryhmän henkilöt asiantuntija- tai päällikköasemassa. Tulosten mukaan ei kuitenkaan voida todeta, että näiden kahden ryhmän urakäsitykset olisivat huomattavasti erilaisia. Onnistunut ura nähdään useimmin subjektiivisesti haastavana, omien tavoitteiden ja kehittymisen saavuttamisena.

A survey on coverage path planning for robotics

Coverage Path Planning (CPP) is the task of determining a path that passes over all points of an area or volume of interest while avoiding obstacles. This task is integral to many robotic applications, such as vacuum cleaning robots, painter robots, autonomous underwater vehicles creating image mosaics, demining robots, lawn mowers, automated harvesters, window cleaners and inspection of complex structures, just to name a few. A considerable body of research has addressed the CPP problem. However, no updated surveys on CPP reflecting recent advances in the field have been presented in the past ten years. In this paper, we present a review of the most successful CPP methods, focusing on the achievements made in the past decade. Furthermore, we discuss reported field applications of the described CPP methods. This work aims to become a starting point for researchers who are initiating their endeavors in CPP. Likewise, this work aims to present a comprehensive review of the recent breakthroughs in the field, providing links to the most interesting and successful works

Fourier-based registration for robust forward-looking sonar mosaicing in low-visibility underwater environments

Vehicle operations in underwater environments are often compromised by poor visibility conditions. For instance, the perception range of optical devices is heavily constrained in turbid waters, thus complicating navigation and mapping tasks in environments such as harbors, bays, or rivers. A new generation of high-definition forward-looking sonars providing acoustic imagery at high frame rates has recently emerged as a promising alternative for working under these challenging conditions. However, the characteristics of the sonar data introduce difficulties in image registration, a key step in mosaicing and motion estimation applications. In this work, we propose the use of a Fourier-based registration technique capable of handling the low resolution, noise, and artifacts associated with sonar image formation. When compared to a state-of-the art region-based technique, our approach shows superior performance in the alignment of both consecutive and nonconsecutive views as well as higher robustness in featureless environments. The method is used to compute pose constraints between sonar frames that, integrated inside a global alignment framework, enable the rendering of consistent acoustic mosaics with high detail and increased resolution. An extensive experimental section is reported showing results in relevant field applications, such as ship hull inspection and harbor mapping

Non-Markovian Dynamics in Continuous Variable Quantum Systems

The present manuscript represents the completion of a research path carried forward during my doctoral studies in the University of Turku. It contains information regarding my scientific contribution to the field of open quantum systems, accomplished in collaboration with other scientists. The main subject investigated in the thesis is the non-Markovian dynamics of open quantum systems with focus on continuous variable quantum channels, e.g. quantum Brownian motion models. Non-Markovianity is here interpreted as a manifestation of the existence of a flow of information exchanged by the system and environment during the dynamical evolution. While in Markovian systems the flow is unidirectional, i.e. from the system to the environment, in non-Markovian systems there are time windows in which the flow is reversed and the quantum state of the system may regain coherence and correlations previously lost. Signatures of a non-Markovian behavior have been studied in connection with the dynamics of quantum correlations like entanglement or quantum discord. Moreover, in the attempt to recognisee non-Markovianity as a resource for quantum technologies, it is proposed, for the first time, to consider its effects in practical quantum key distribution protocols. It has been proven that security of coherent state protocols can be enhanced using non-Markovian properties of the transmission channels. The thesis is divided in two parts: in the first part I introduce the reader to the world of continuous variable open quantum systems and non-Markovian dynamics. The second part instead consists of a collection of five publications inherent to the topic.

Simulation of the Interaction Mean Free Path between Neutrons and TRISO Particles

The interaction mean free path between neutrons and TRISO particles is simulated using scripts written in MATLAB to solve the increasing error present with an increase in the packing factor in the reactor physics code Serpent. Their movement is tracked both in an unbounded and in a bounded space. Their track is calculated, depending on the program, linearly directly using the position vectors of the neutrons and the surface equations of all the fuel particles; by dividing the space in multiple subspaces, each of which contain a fraction of the total number of particles, and choosing the particles from those subspaces through which the neutron passes through; or by choosing the particles that lie within an infinite cylinder formed on the movement axis of the neutron. The estimate from the current analytical model, based on an exponential distribution, for the mean free path, utilized by Serpent, is used as a reference result. The results from the implicit model in Serpent imply a too long mean free path with high packing factors. The received results support this observation by producing, with a packing factor of 17 %, approximately 2.46 % shorter mean free path compared to the reference model. This is supported by the packing factor experienced by the neutron, the simulation of which resulted in a 17.29 % packing factor. It was also observed that the neutrons leaving from the surfaces of the fuel particles, in contrast to those starting inside the moderator, do not follow the exponential distribution. The current model, as it is, is thus not valid in the determination of the free path lengths of the neutrons.

Suomalaisen pienpanimon kansainvälistymismahdollisuudet Ruotsissa

Työn tavoitteena on kartoittaa suomalaisen pienpanimon kansainvälistymismahdollisuuksia valitulla kohdemarkkina-alueella, hankkia kattavasti informaatiota kansainvälistymiseen vaadittavista asioista, sekä arvioida toimeksiantajayrityksen valmiuksia kansainvälistymiseen. Tarkoituksena on näiden asioiden perusteella muodostaa suomalaiselle pienpanimolle sopiva kansainvälistymispolku, valita operaatiomuoto kohdemarkkinoilla toimimiseksi sekä hahmotella jo ensimmäiset askeleet kansainvälisen toiminnan aloittamiseksi. Kansainvälistyminen on kokonaisvaltainen oppimis- ja muutosprosessi, jonka tuloksena yritys laajentaa omaa toimintaansa kansainvälisille markkinoille. Pienpanimolle kansainvälistyminen asettaa haasteita etenkin resurssien rajallisuuteen liittyen, mutta resursseja voidaan kehittää ja lisätä yritysten välisen verkostoitumisen ja muiden organisaatioiden avulla. Tietämyksen kasvattaminen ja verkostoaseman parantaminen syventää yrityksen kansainvälistä toimintaa ja vie kansainvälistymisprosessia eteenpäin. Suomalaisen pienpanimon kansainvälistymisessä avainasemaan nousee oikean yhteistyökumppanin löytäminen. Huolellinen valmistautuminen parantaa mahdollisuuksia onnistua, mutta kansainvälistymistä voi myös harjoitella ja samalla verkostoitua kohdemarkkinoilla hyödyntämällä pienpanimoille tyypillisiä kansainvälisiä yhteistyömuotoja.

Evaluation of energy expenditure in forward and backward movements performed by soccer referees

The aim of this study was to measure the energy expenditure for locomotor activities usually performed by soccer referees during a match (walking, jogging, and running) under laboratory conditions, and to compare forward with backward movements. The sample was composed by 10 male soccer referees, age 29±7.8 years, body mass 77.5±6.2 kg, stature 1.78±0.07 m and professional experience of 7.33±4.92 years. Referees were evaluated on two separate occasions. On the first day, maximal oxygen uptake (VO2max) was determined by a maximal treadmill test, and on the second day, the oxygen consumption was determined in different speeds of forward and backward movements. The mean VO2max was 41.20±3.60 mL·kg-1·min-1 and the mean heart rate achieved in the last stage of the test was 190.5±7.9 bpm. When results of forward and backward movements were compared at 1.62 m/s (walking speed), we found significant differences in VO2, in metabolic equivalents, and in kcal. However, the same parameters in forward and backward movements at jogging velocities (2.46 m/s) were not significantly different, showing that these motor activities have similar intensity. Backward movements at velocities equivalent to walking and jogging are moderate-intensity activities, with energy expenditure less than 9 kcal. Energy expenditure was overestimated by at least 35% when calculated by mathematical equations. In summary, we observed that backward movements are not high-intensity activities as has been commonly reported, and when calculated using equations available in the literature, energy expenditure was overestimated compared to the values obtained by indirect calorimetry.

Harrod sob análise: path-dependence, tempo histórico e mudança estrutural endógena

Harrod under analysis: path-dependence, historic time and endogenous structural change. The article aims to demonstrate how the Harrod's approach (1937, 1938, 1948) can offer theoretical elements to form a complex, historicists and non-determinist view of the economic system. The relaxation of the constant warranty rate hypothesis make possible the system suffers endogenous qualitative change. It results in the notion of path-dependence and historic time. By the endogenization of the expectations and the existence of turn-points mechanisms, this approach allows a synthesis between non-convergency and economic regulation.

Path Analysis of Online Users Using Clickstream Da-ta: Case Online Magazine Website

This paper explores behavioral patterns of web users on an online magazine web-site. The goal of the study is to first find and visualize user paths within the data generated during collection, and to identify some generic behavioral typologies of user behavior. To form a theoretical foundation for processing data and identifying behavioral ar-chetypes, the study relies on established consumer behavior literature to propose typologies of behavior. For data processing, the study utilizes methodologies of ap-plied cluster analysis and sequential path analysis. Utilizing a dataset of click stream data generated from the real-life clicks of 250 ran-domly selected website visitors over a period of six weeks. Based on the data collect-ed, an exploratory method is followed in order to find and visualize generally occur-ring paths of users on the website. Six distinct behavioral typologies were recog-nized, with the dominant user consuming mainly blog content, as opposed to editori-al content. Most importantly, it was observed that approximately 80% of clicks were of the blog content category, meaning that the majority of web traffic occurring in the site takes place in content other than the desired editorial content pages. The out-come of the study is a set of managerial recommendations for each identified behavioral archetype.

The Path of Possibilities

by Ilan Averbuch presented to Brock in 1988.

Mackenzie Chown Path

Path running next to the Mackenzie Chown Complex.