Kansakoulunopettaja Lea Tamminen 17/12 1966

Kirje 17.12.1966

Calibration of time domain reflectometry (DTR) for soil moisture measurements in cultivated peat soils

Tiivistelmä: TDR-mittausten kalibrointi viljeltyjen turvemaiden kosteuden mittaamiseen

Calibration of a desktop scanner and digital image analysis procedure for quantification of a root morphology

Selostus: Tasoskannerin ja digitaalisen kuva-analyysimenetelmän kalibrointi juurten morfologian kvantifioimiseksi

Electric field calibration method for scanning electron microscope

This paper proposes a calibration method which can be utilized for the analysis of SEM images. The field of application of the developed method is a calculation of surface potential distribution of biased silicon edgeless detector. The suggested processing of the data collected by SEM consists of several stages and takes into account different aspects affecting the SEM image. The calibration method doesn’t pretend to be precise but at the same time it gives the basics of potential distribution when the different biasing voltages applied to the detector.

Performance Evaluation and Calibration of Machine Vision Measurement

This thesis presents the calibration and comparison of two systems, a machine vision system that uses 3 channel RGB images and a line scanning spectral system. Calibration. is the process of checking and adjusting the accuracy of a measuring instrument by comparing it with standards. For the RGB system self-calibrating methods for finding various parameters of the imaging device were developed. Color calibration was done and the colors produced by the system were compared to the known colors values of the target. Software drivers for the Sony Robot were also developed and a mechanical part to connect a camera to the robot was also designed. For the line scanning spectral system, methods for the calibrating the alignment of the system and the measurement of the dimensions of the line scanned by the system were developed. Color calibration of the spectral system is also presented.

Lea. Näytelmä yhdessä näytöksessä

Kevättalvella 1869 kokoontui Kaarlo Bergbomin kotiin Helsingin Unioninkadulle joukko ystäviä ja teatterinharrastajia. Näiden joukossa oli Ruotsalaisessa teatterissa mainetta saanut Hedvig Charlotte Raa. Bergbom oli vuodenvaihteessa saanut Viipurin suomalaiselta kirjallisuuden seuralta lainaksi Aleksis Kiven raamattuaiheisen "Lea"-näytelmän käsikirjoituksen ja näyttelijä Oskar Gröneqvist (Vilho) luki sen seurueelle kaikkien ihastukseksi. Kivi oli antanut luvan näytelmän esittämiseen ollen kirjeessään huolissaan siitä, ettei kukaan "tutenttipoika" (student) osaisi Lean kaltaista naisroolia esittää. Tuolloin oli vielä yleistä että miehet esittivät myös naisrooleja. Charlotte Raa saatiin kuitenkin suostuteltua esittämään Lean osa. Kun Raa ei osannut lainkaan suomea, näytelmä käännettiin hänelle ruotsiksi ja Raa opetteli kaiken ulkoa. Kuten tunnettua muodostui suomenkielinen "Lean" esitys näyttelijän hieman oudosta ääntämisestä huolimatta Ruotsalaisessa teatterissa (Nya teatern) 10. toukokuuta 1869 suureksi menestykseksi ja siitä katsotaan suomenkielisen ammattiteatterin saaneen alkunsa. Kivi lienee nähnyt "Lean" Arkadia-teatterissa 1.11.1870. Kivi oli saanut käsikirjoituksen Siuntion Fanjunkarsissa alkuvuodesta 1868 valmiiksi ja lähetti "Lean", "Sankarteoksen" ja "Leon ja Liinan" lehtori B. F. Godenhjelmille kielen korjausta varten ja että tämä toimittaisi näytelmät Viipurin suomalaiselle kirjallisuuden seuralle. Seura julkaisi näistä kolmesta käsikirjoituksesta "Lean" helmikuussa 1869 ja sen yhtenä puoltajana on varmasti ollut seuran jäsen, kirkkoherra Mortimer Forstén. Tämä oli tullut Kivelle tutuksi jo Nurmijärvellä pappina ollessaan. Myös Lean painos oli 500 kappaletta.

Dual light barrier method for six degrees of freedom tool center point calibration of an industrial robot

Tool center point calibration is a known problem in industrial robotics. The major focus of academic research is to enhance the accuracy and repeatability of next generation robots. However, operators of currently available robots are working within the limits of the robot´s repeatability and require calibration methods suitable for these basic applications. This study was conducted in association with Stresstech Oy, which provides solutions for manufacturing quality control. Their sensor, based on the Barkhausen noise effect, requires accurate positioning. The accuracy requirement admits a tool center point calibration problem if measurements are executed with an industrial robot. Multiple possibilities are available in the market for automatic tool center point calibration. Manufacturers provide customized calibrators to most robot types and tools. With the handmade sensors and multiple robot types that Stresstech uses, this would require great deal of labor. This thesis introduces a calibration method that is suitable for all robots which have two digital input ports free. It functions with the traditional method of using a light barrier to detect the tool in the robot coordinate system. However, this method utilizes two parallel light barriers to simultaneously measure and detect the center axis of the tool. Rotations about two axes are defined with the center axis. The last rotation about the Z-axis is calculated for tools that have different width of X- and Y-axes. The results indicate that this method is suitable for calibrating the geometric tool center point of a Barkhausen noise sensor. In the repeatability tests, a standard deviation inside robot repeatability was acquired. The Barkhausen noise signal was also evaluated after recalibration and the results indicate correct calibration. However, future studies should be conducted using a more accurate manipulator, since the method employs the robot itself as a measuring device.

Näytelmiä - II, Lea. Arabian-pulweria

Impr.: A. E. Modeen.

Novel control, haptic and calibration methods for teleoperated electrohydraulic servo systems

The aim of this thesis is to propose a novel control method for teleoperated electrohydraulic servo systems that implements a reliable haptic sense between the human and manipulator interaction, and an ideal position control between the manipulator and the task environment interaction. The proposed method has the characteristics of a universal technique independent of the actual control algorithm and it can be applied with other suitable control methods as a real-time control strategy. The motivation to develop this control method is the necessity for a reliable real-time controller for teleoperated electrohydraulic servo systems that provides highly accurate position control based on joystick inputs with haptic capabilities. The contribution of the research is that the proposed control method combines a directed random search method and a real-time simulation to develop an intelligent controller in which each generation of parameters is tested on-line by the real-time simulator before being applied to the real process. The controller was evaluated on a hydraulic position servo system. The simulator of the hydraulic system was built based on Markov chain Monte Carlo (MCMC) method. A Particle Swarm Optimization algorithm combined with the foraging behavior of E. coli bacteria was utilized as the directed random search engine. The control strategy allows the operator to be plugged into the work environment dynamically and kinetically. This helps to ensure the system has haptic sense with high stability, without abstracting away the dynamics of the hydraulic system. The new control algorithm provides asymptotically exact tracking of both, the position and the contact force. In addition, this research proposes a novel method for re-calibration of multi-axis force/torque sensors. The method makes several improvements to traditional methods. It can be used without dismantling the sensor from its application and it requires smaller number of standard loads for calibration. It is also more cost efficient and faster in comparison to traditional calibration methods. The proposed method was developed in response to re-calibration issues with the force sensors utilized in teleoperated systems. The new approach aimed to avoid dismantling of the sensors from their applications for applying calibration. A major complication with many manipulators is the difficulty accessing them when they operate inside a non-accessible environment; especially if those environments are harsh; such as in radioactive areas. The proposed technique is based on design of experiment methodology. It has been successfully applied to different force/torque sensors and this research presents experimental validation of use of the calibration method with one of the force sensors which method has been applied to.

Simulation and material calibration of ultra high strength steel (UHSS) S960 welded joint under static tensile test utilizing finite element method (FEM)

The aim of this work was to calibrate the material properties including strength and strain values for different material zones of ultra-high strength steel (UHSS) welded joints under monotonic static loading. The UHSS is heat sensitive and softens by heat due to welding, the affected zone is heat affected zone (HAZ). In this regard, cylindrical specimens were cut out from welded joints of Strenx® 960 MC and Strenx® Tube 960 MH, were examined by tensile test. The hardness values of specimens’ cross section were measured. Using correlations between hardness and strength, initial material properties were obtained. The same size specimen with different zones of material same as real specimen were created and defined in finite element method (FEM) software with commercial brand Abaqus 6.14-1. The loading and boundary conditions were defined considering tensile test values. Using initial material properties made of hardness-strength correlations (true stress-strain values) as Abaqus main input, FEM is utilized to simulate the tensile test process. By comparing FEM Abaqus results with measured results of tensile test, initial material properties will be revised and reused as software input to be fully calibrated in such a way that FEM results and tensile test results deviate minimum. Two type of different S960 were used including 960 MC plates, and structural hollow section 960 MH X-joint. The joint is welded by BöhlerTM X96 filler material. In welded joints, typically the following zones appear: Weld (WEL), Heat affected zone (HAZ) coarse grained (HCG) and fine grained (HFG), annealed zone, and base material (BaM). Results showed that: The HAZ zone is softened due to heat input while welding. For all the specimens, the softened zone’s strength is decreased and makes it a weakest zone where fracture happens while loading. Stress concentration of a notched specimen can represent the properties of notched zone. The load-displacement diagram from FEM modeling matches with the experiments by the calibrated material properties by compromising two correlations of hardness and strength.

Dynamic Workload Parallelization and System Calibration on Single-Chip Cloud Computer

Many-core systems are emerging from the need of more computational power and power efficiency. However there are many issues which still revolve around the many-core systems. These systems need specialized software before they can be fully utilized and the hardware itself may differ from the conventional computational systems. To gain efficiency from many-core system, programs need to be parallelized. In many-core systems the cores are small and less powerful than cores used in traditional computing, so running a conventional program is not an efficient option. Also in Network-on-Chip based processors the network might get congested and the cores might work at different speeds. In this thesis is, a dynamic load balancing method is proposed and tested on Intel 48-core Single-Chip Cloud Computer by parallelizing a fault simulator. The maximum speedup is difficult to obtain due to severe bottlenecks in the system. In order to exploit all the available parallelism of the Single-Chip Cloud Computer, a runtime approach capable of dynamically balancing the load during the fault simulation process is used. The proposed dynamic fault simulation approach on the Single-Chip Cloud Computer shows up to 45X speedup compared to a serial fault simulation approach. Many-core systems can draw enormous amounts of power, and if this power is not controlled properly, the system might get damaged. One way to manage power is to set power budget for the system. But if this power is drawn by just few cores of the many, these few cores get extremely hot and might get damaged. Due to increase in power density multiple thermal sensors are deployed on the chip area to provide realtime temperature feedback for thermal management techniques. Thermal sensor accuracy is extremely prone to intra-die process variation and aging phenomena. These factors lead to a situation where thermal sensor values drift from the nominal values. This necessitates efficient calibration techniques to be applied before the sensor values are used. In addition, in modern many-core systems cores have support for dynamic voltage and frequency scaling. Thermal sensors located on cores are sensitive to the core's current voltage level, meaning that dedicated calibration is needed for each voltage level. In this thesis a general-purpose software-based auto-calibration approach is also proposed for thermal sensors to calibrate thermal sensors on different range of voltages.

Calibration and simulations of SIXS-P's response to energetic particles

The Solar Intensity X-ray and particle Spectrometer (SIXS) on board BepiColombo's Mercury Planetary Orbiter (MPO) will study solar energetic particles moving towards Mercury and solar X-rays on the dayside of Mercury. The SIXS instrument consists of two detector sub-systems; X-ray detector SIXS-X and particle detector SIXS-P. The SIXS-P subdetector will detect solar energetic electrons and protons in a broad energy range using a particle telescope approach with five outer Si detectors around a central CsI(Tl) scintillator. The measurements made by the SIXS instrument are necessary for other instruments on board the spacecraft. SIXS data will be used to study the Solar X-ray corona, solar flares, solar energetic particles, the Hermean magnetosphere, and solar eruptions. The SIXS-P detector was calibrated by comparing experimental measurement data from the instrument with Geant4 simulation data. Calibration curves were produced for the different side detectors and the core scintillator for electrons and protons, respectively. The side detector energy response was found to be linear for both electrons and protons. The core scintillator energy response to protons was found to be non-linear. The core scintillator calibration for electrons was omitted due to insufficient experimental data. The electron and proton acceptance of the SIXS-P detector was determined with Geant4 simulations. Electron and proton energy channels are clean in the main energy range of the instrument. At higher energies, protons and electrons produce non-ideal response in the energy channels. Due to the limited bandwidth of the spacecraft's telemetry, the particle measurements made by SIXS-P have to be pre-processed in the data processing unit of the SIXS instrument. A lookup table was created for the pre-processing of data with Geant4 simulations, and the ability of the lookup table to provide spectral information from a simulated electron event was analysed. The lookup table produces clean electron and proton channels and is able to separate protons and electrons. Based on a simulated solar energetic electron event, the incident electron spectrum cannot be determined from channel particle counts with a standard analysis method.

Mitä musiikkiopistojen pääsykokeissa testataan? : tutkimus Helsingissä sijaitsevien SML:n liittoon kuuluvien musiikkiopistojen pääsykokeista

Tutkimuksen tarkoituksena oli selvittää, mitä musiikkiopistoissa käytössä olevat pääsykoetestit mittaavat sekä mitataanko niissä varsinaisesti musikaalisuutta. Lisäksi tutkimuksessa tarkasteltiin lahjakkuuden ja musikaalisuuden teorioita sekä niiden suhdetta käytössä oleviin pääsykoetesteihin. Tutkimus kohdistui Helsingissä sijaitsevien Suomen musiikkioppilaitosten liittoon (SML) kuuluvien musiikkiopistojen 4-7-vuotiaille pyrkijöille suunnattuihin pääsykokeisiin. Tutkimusaineisto koostui pääsykoekäytäntöjen osalta musiikkiopistojen rehtoreiden teemahaastattelusta sekä analysoitavaksi saaduista kirjallisista yksilö- tai ryhmätesteistä. Helsingissä sijaitsevista yhdestätoista musiikkiopistosta kymmenen osallistui teemahaastatteluun (10/11), ja ensimmäisessä vaiheessa mukana olleista kymmenestä opistosta seitsemällä oli tarjota myös pyydetty kirjallinen materiaali tutkimuksen toista vaihetta, kirjallisen testiaineiston analyysia varten (7/10). Haastattelujen ja testien analyysin perusteella saatiin selville musiikillisia ja ei-musiikillisia osatekijöitä, joiden mittaamisesta pääsykoe muodostui. Tutkimusmenetelmänä oli sisällönanalyysi. Johtopäätösten kannalta oli olennaista analysoida saatuja tuloksia suhteessa teoriataustassa esiteltyihin lahjakkuus- ja musikaalisuuskäsityksiin. Tulosten valossa on ilmeistä, että musikaalisuuden määrittelyn ongelmallisuudesta johtuen ei voida yksiselitteisesti vastata kysymykseen siitä, mitataanko pääsykoetesteissä juuri musikaalisuutta. Käytetyt testit mittaavat sekä musiikillisia että ei-musiikillisia tekijöitä ja erityisesti niihin harjaantumista. Testien kehittämisessä tulisi selkeämmin huomioida lapsen ikäkauden asettamat haasteet sekä lapsen yleiseen kehitykseen että erityiseen musiikilliseen kehitykseen kohdistuva tutkimus.