京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第12813号 / 論理博第1539号 / 新制||理||1577(附属図書館) / 31300 / (主査)教授 嶺重 慎, 准教授 前田 啓一, 教授 長田 哲也 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DFAM

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The surface albedo significantly modulates the atmospheric energy budget and, thus, vertical radiation, energy, and mass fluxes. Therefore, it regulates the local and regional effects of climate warming. Over a forest canopy, the surface albedo mainly depends on the seasonal leaf state. Furthermore, for certain surface types, such as snow, it has been shown that the surface albedo changes as a function of cloudiness. A similar effect is expected over forest surfaces, leading to complex feedback loops between forest surfaces and climate. To investigate these processes, a pilot study was performed at the Leipzig floodplain crane to observe the forest canopy albedo under different atmospheric conditions in 2021. First analyses revealed a dependency of the forest albedo from the cloud state, which is slightly stronger in the near-infrared wavelength range compared to the visible wavelength range. / Der atmosphärische Strahlungshaushalt und damit auch die vertikale Strahlungsverteilung, Energie- und Massenflüsse werden signifikant durch die Bodenalbedo gesteuert. Diese regulieren somit lokale und regionale Effekte der Klimaerwärmung. Über einem Wald hängt die Bodenalbedo hauptsächlich vom saisonalen Blattstatus ab. Zudem wurde für bestimmte Bodentypen wie Schneeoberflächen gezeigt, dass die Bodenalbedo eine Funktion der Bewölkung ist. Ähnlicher Effekte werden für Waldoberflächen erwartet, welche zu komplexen Rückkopplungseffekten zwischenWaldoberflächen und dem Klima führen. Um diese Prozesse zu untersuchen wurde im Jahr 2021 eine Vorstudie am Leipziger Auwaldkran durchgeführt, um die Waldalbedo unter verschiedenen atmosphärischen Bedingungen zu beobachten. Erste Analysen zeigen, dass auch die Albedo des Waldes von den Bewölkungsbedingungen abhängt. Der Effekt ist dabei etwas stärker im nah-infrarotem als im sichtbaren Wellenlängenbereich zu beobachten.

Cloud condensation nucleus control alter cloud solar albedo through cloud droplet size. Here, we leverage anthropogenic emissions at the North Slope of Alaska as a natural laboratory to study relationships between aerosols and Arctic liquid-containing clouds. Averaging 14 years of MODIS observations, we found a reduction in temporally averaged cloud effective radius ( er ) of up to 1.0 μm related to localized pollution. Pronounced regional gradients in cloud frequency of occurrence and liquid water path prohibit the detection of potential changes of these variables. Observed changes of er alter radiative fluxes and increase cloud-reflected shortwave radiation by up to 0.8 W m−2 in the Prudhoe Bay area for the period covered by observations (April–September). Due to the frequent occurrence of liquid-containing clouds, this implies that enhanced local emissions in Arctic regions can impact climate processes.

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Scania needs to reconfigure their factories quickly to meet the future demands of the market. The process of reconfiguring factories starts with the factory layouts. Factory design is a complicated detail-oriented process, and if major physical changes on the factory floor and installations fail, it affects the entire production flow. It is an expensive and time consuming process to rectify these errors. Hence, it is extremely important that the installations are both quick and accurate. So, Scania wants to investigate how Immersive Virtual Reality could be used in the Factory layout design process. This thesis addresses how to utilize VR with existing technologies at Scania, by mapping the capabilities of VR to the needs of Scania. A function of interest to Scania is the possibility to import data, such as Point Clouds, CAD Objects and Factory Layouts, to create a coordinated VR platform. After understanding the VR technology, it was proved possible to import and visualize all of these data, after exporting it to a format that was readable by the VR system. Once the VR platform was setup, based on the imported models, the next step was to evaluate the aspects of working with VR, as compared to working with Scania’s Factory CAD system –“LayCAD”. It was assessed that the Immersive VR system offers better visualization, evaluation and realization of layout changes, compared to the LayCAD system. But the use of VR requires additional skills, time and cost to setup the VR platform. Based on the degree of maturity of the VR technology and the current state of Scania, it was concluded that VR cannot yet serve as a standalone solution for layouts within Scania. For an efficient factory development process, it is more appropriate to work with both systems in combination, where Immersive VR is used as an additional visualization or verification tool for presenting and evaluating conceptual layouts. / Scania behöver omkonfigurera sina fabriker snabbt för att möta marknadens framtida krav. Processen med omkonfigurering av fabriker börjar med fabrikslayouterna. Fabriksdesign är en komplicerad detaljorienterad process, och om stora fysiska förändringar på fabrikens golv och installationer misslyckas påverkar det hela produktionsflödet. Det är en dyr och tidskrävande process att rätta till dessa fel. Därför är det extremt viktigt att installationerna är både snabba och korrekta. Så, Scania vill undersöka hur Immersive Virtual Reality (VR) kan användas i fabrikslayoutdesignprocessen. Denna avhandling beskriver hur man kan använda VR med befintlig teknik i Scania genom att kartlägga VR: s förmåga att möta Scanias behov. En funktion av intresse för Scania är möjligheten att importera data, såsom Point Clouds, CAD Objects och Factory Layouts, för att skapa en samordnad VR-plattform. Efter att ha förstått VR-tekniken visade det sig vara möjligt att importera och visualisera alla dessa data efter att ha exporterat dem till ett format som var läsbart av VR-systemet. När VR-plattformen var inställd, baserad på de importerade modellerna, var nästa steg att utvärdera aspekterna av att arbeta med VR, jämfört med att arbeta med Scanias Factory CAD-system - "LayCAD". Det bedömdes att systemet för Immersive VR ger bättre visualisering, utvärdering och realisering av layoutändringar jämfört med LayCAD-systemet. Men användningen av VR kräver ytterligare färdigheter, tid och kostnad för att installera VR-plattformen. Baserat på mognadsgraden av VR-tekniken och Scanias nuvarande IT-användning, drogs slutsatsen att VR ännu inte kan fungera som en fristående lösning för layouter inom Scania. För en effektiv fabriksutvecklingsprocess är det mer lämpligt att arbeta med båda systemen i kombination, där Immersive VR används som ett extra visualiserings- eller verifieringsverktyg för att presentera och utvärdera konceptuella layouter.

Yes / This paper proposes a stable and accurate object registration pipeline for markerless augmented reality applications. We present two novel algorithms for object recognition and matching to improve the registration accuracy from model to scene transformation via point cloud fusion. Whilst the first algorithm effectively deals with simple scenes with few object occlusions, the second algorithm handles cluttered scenes with partial occlusions for robust real-time object recognition and matching. The computational framework includes a locally supported Gaussian weight function to enable repeatable detection of 3D descriptors. We apply a bilateral filtering and outlier removal to preserve edges of point cloud and remove some interference points in order to increase matching accuracy. Extensive experiments have been carried to compare the proposed algorithms with four most used methods. Results show improved performance of the algorithms in terms of computational speed, camera tracking and object matching errors in semi-cluttered and partial-occluded scenes. / Shanxi Natural Science and Technology Foundation of China, grant number 2016JZ026 and grant number 2016KW-043).

As Industry 4.0 and Internet of Things are established across factories and enterprises, the interest for learning more about these concepts and the possibilities they provide for condition based maintenance is expressed by a factory in Sweden. By addressing the aspects of Internet of Things and Industry 4.0, a system for performing data acquisition from sensors in an industrial environment is developed using Arrowhead Framework. This framework is evaluated around its suitability for this kind of application, and regarding what the framework may provide to the factory compared to other solutions and systems. A solution featuring a system based on Arrowhead Framework is developed, implemented, and briefly tested. The system is successful in performing data acquisition, and Arrowhead Framework is considered a viable option that may be used to provide a system tailored for different purposes, presumed that the factory is prepared to allocate resources on developing a solution around it.

Various physical mechanisms that affect radiowave propagation at millimetre wavelengths are considered. Current modelling weaknesses are highlighted and new improved models or more appropriate modelling approaches are suggested. Interference and resonance phenomena in the scattering of spherical ice and water particles are reviewed. The long standing problem of the numerous resonances observed in the scattering diagrams of dielectric spheres is answered. The spatial structure and the physical characteristics of non-precipitable ice and water clouds are reviewed. Extinction and back scattering calculations for a wide variety of cloud models over the entire millimetre frequency spectrum are given. Multiple scattering and the effects of super-large drops in clouds are also dealt with. The potential of a spaceborne instrument in deducing information about the vertical structure of various cloud types is examined. Attenuation and reflectivity profiles resulting from various cloud types are calculated for a nadir pointing fixed beam millimetre wave radar operating at 94 GHz. The physics and application of the equation of radiative transfer to millimetre wave propagation in the earth's atmosphere are given and also is the solution of this equation for a typical millimetre wave remote sensing application. The theory of gaseous absorption at millimetre wavelengths is presented and an improved modelling approach is proposed for the calculation of the absorption and dispersion spectra of atmospheric gases. The effects of trace gases on communication systems operating at high altitudes are for the first time reported. Finally the use of the 60 GHz oxygen absorption band for top-side air traffic control/navigation and broadband transmission purposes is studied.

In this thesis, the radiative effect of Arctic clouds during early summer is investigated based on observations collected aboard the research vessel Polarstern during the expedition PS106 conducted in 2017 in combination with passive satellite observations. The interactions of clouds with radiation, and the relevance of several macro- and microphysical properties of clouds and surface conditions are analyzed. An investigation of the small-scale variability of solar radiation on an ice floe based on a network of autonomous pyranometers covering an area of 0.83 km x 1.59 km, and the period from 4-16 June 2017 is given. Five distinct sky conditions are identified, and the mean and variance of atmospheric transmittance of global radiation are determined. Using a wavelet-based multi-resolution analysis, a comparison of individual station records and spatially averaged observations indicates that the absolute magnitude and scale-dependence of variability contain characteristic features for different sky conditions. For overcast conditions, distinctive patterns are identified in the diurnal variability and spatial distribution of the network observations, presumably caused by multiple reflection radiation between surface and cloud base in combination with the inhomogeneous surface conditions. A sensitivity analysis of radiative fluxes is performed for clear-sky and cloudy conditions using a 1-dimensional radiative transfer model, and is used as a basis to investigate how well state-of-the-art shipborne and passive satellite remote sensing observations can constrain the radiative effect of clouds and can serve to quantify the Arctic radiation budget. Cloud properties derived from the shipborne remote sensing observations with the Cloudnet algorithm are used as input for radiative transfer simulations. Simulated fluxes are compared to shipborne observations of the downward-terrestrial and solar fluxes as well as satellite products from CERES (Clouds and the Earth's Radiant Energy System, SYN1deg Ed. 4.1) to test closure of simulated and observed radiative fluxes, and to analyse the cloud radiative effect. Closure is achieved for clear-sky conditions. Based on selected case studies and an analysis for the entire PS106 period, the largest discrepancies are identified for low-level stratus, precipitation and ice clouds. Moreover, the cloud radiative effect inferred along the cruise track is compared to the entire Arctic to expand the regional context, making use of the wide spatial coverage of the CERES products. The results indicate a strong contribution of the solar flux to the radiation budget for the study period. Due to the reduction of solar radiation by clouds, a cooling effect of -8.8 W/m² and -9.3 W/m² is found at the surface for the PS106 cruise and the central Arctic, respectively. The similarity of local and regional CRE suggests that the PS106 cloud observations can be considered as representative of Arctic cloud conditions during the early summer of 2017.:Contents 1 Introduction 1.1 Motivation 1.2 Characteristics of Arctic Clouds 1.3 Effect of Arctic Clouds on the Radiation Budget 1.4 Link Between Arctic Clouds and Surface Conditions 1.5 Objectives of (AC)3 and this Thesis 1.6 Outline 2 Theoretical Background 2.1 Radiative Quantities 2.2 Radiative Interactions 2.2.1 Absorption 2.2.2 Scattering and Extinction 2.3 Radiative Transfer Equation 2.4 Radiative Transfer in the Arctic 2.4.1 Surface Reflection and Transmission 2.4.2 Clear-sky Conditions 2.4.3 Optical Properties of Clouds 2.5 Radiative Transfer Modelling 2.5.1 Two-stream Approximation 2.5.2 Correlated k -distribution 2.5.3 RRTMG 2.6 Energy Budget and Cloud Radiative Effect 3 PS106 Expedition, Instrumentation, Data sets, and Methods 3.1 Instrumentation 3.1.1 Pyranometer Network 3.1.2 Ship-borne Instrumentation 3.2 Data sets 3.2.1 Cloudnet 3.2.2 CERES data set 3.2.3 Ancillary data set 3.3 General Conditions During PS106 3.3.1 Synoptic and Surface Conditions 3.3.2 Atmospheric Temperature and Humidity Conditions 3.3.3 Statistical Analysis of Cloud Properties 3.4 Radiative Transfer Simulation Setup 4 Sensitivity Analysis of Arctic Fluxes 4.1 Clear-sky Perturbations 4.1.1 Atmosphere 4.1.2 Surface 4.2 Clear-sky Radiative Flux Uncertainty 4.3 Cloud Perturbations 4.3.1 Cloud Water Path 4.3.2 Cloud Particle Effective Radius 4.3.3 Liquid Fraction and Surface Albedo 4.3.4 Cloud Base Height 4.3.5 Cloud Geometrical Thickness 4.4 Synopsis 5 Cloud Induced Spatiotemporal Variability of Solar Radiation 5.1 Data Analysis 5.1.1 Data Processing 5.1.2 Sky Classification 5.2 Case Studies 5.2.1 Clear-sky Case 5.2.2 Overcast Case 5.2.3 Thin Cloud Case 5.2.4 Multilayer Case 5.2.5 Broken Cloud Case 5.3 Wavelet-based Multiresolution Analysis 5.4 Synopsis and Discussion 6 Radiation Closure 6.1 Radiative Flux Comparison Between CERES and T-CARS 6.2 Radiative Closure for Clear-sky Atmosphere 6.3 Radiative Closure for Cloudy Atmosphere 6.4 Synopsis and Discussion 7 Case Studies 7.1 Clear-sky Case 7.2 Single and Multilayer Ice Cloud Case 7.3 Mixed Phase Cloud Case 7.4 Synopsis 8 Radiation Budget and Cloud Radiative Effects 8.1 Cloud Radiative Effect (CRE) Analysis 8.2 Radiation Budget 8.3 Synopsis 9 Summary, Conclusions and Outlook 9.1 Summary and Conclusions 9.2 Outlook Appendix A Cloud Microphysical Properties During PS106 B CRE of Sensitivity Analysis C CERES Aerosol Products D Additional Observations Literature List of Abbreviations List of Symbols List of Figures List of Tables Acknowledgements