Reduced Order Controller Design for Robust Output Regulation

We study robust output regulation for parabolic partial differential equations and other infinite-dimensional linear systems with analytic semigroups. As our main results we show that robust output tracking and disturbance rejection for our class of systems can be achieved using a finite-dimensional controller and present algorithms for construction of two different internal model based robust controllers. The controller parameters are chosen based on a Galerkin approximation of the original PDE system and employ balanced truncation to reduce the orders of the controllers. In the second part of the paper we design controllers for robust output tracking and disturbance rejection for a 1D reaction-diffusion equation with boundary disturbances, a 2D diffusion-convection equation, and a 1D beam equation with Kelvin-Voigt damping.Comment: Revised version with minor improvements and corrections. 28 pages, 9 figures. Accepted for publication in the IEEE Transactions on Automatic Contro

Reparations to Victims of Gross Human Rights Violations: The Case of Cambodia

The world community has introduced various legal instruments regarding reparations for gross violations of human rights. In Cambodia, however, reparations for those seriously and systematically deprived of their rights by the Khmer Rouge regime remain an unresolved issue, even after the establishment of the Extraordinary Chambers in the Courts of Cambodia for the Prosecution of Crimes Committed during the Period of Democratic Kampuchea. In so complicated a case as Cambodia\u27s, there are many questions regarding the reparations issue that are left unanswered. This Article examines the issue and offers some recommendations for a feasible and effective reparation program for the Khmer Rouge\u27s victims

Modelling and Evaluation of Fixed-Bed Photocatalytic Membrane Reactors

This work aims at modelling and evaluating a new type of photocatalytic reactors, named fixed-bed photocatalytic membrane reactor (FPMR). Such reactors are based on the deposition of a thin layer of photocatalysts on a permeable substrate by filtration. This layer serves as a photocatalytic membrane, named fixed-bed photocatalytic mem-brane (FPM), which is perpendicularly passed by the reactant solution and illuminated by a suitable light source. One advantage of FPMs is their renewability. The model, which was developed for this reactor, relates the overall reaction rate in the FPM with the intrinsic reaction kinetic at the catalyst surface and accounts for light intensity, structural and optical layer properties as well as the mass transfer in the pores. The concept of FPMR was realised by using a flat sheet membrane cell. It facilitated principal investigations into the reactor performance and the validity of the model. For this purpose, the photocatalytic degradation of organic compounds, such as meth-ylene blue and diclofenac sodium, was conducted at varying conditions. Pyrogenic ti-tania was used as a photocatalyst. The experimental data support the developed mod-el. They also indicate a significant impact of the flow conditions on the overall photo-catalytic activity, even though the Reynolds number in the FPM was very small; the to-tal mass transfer rate in the FPM amounted to more than 1.0 s−1. The experiments also showed a sufficient structural strength of the FPM and photocatalytic stability. In addi-tion, the renewal and regeneration of FPMs was successfully demonstrated. Furthermore, another FPMR was designed by means of submerged ceramic mem-branes. This reactor was mainly used to assess the effectiveness and efficiency of FPMRs at the example of the photocatalytic degradation of oxalic acid. The correspond-ing reactor was run closed loop and in continuous mode. The effectiveness of the reac-tor was evaluated based on common descriptors, such as apparent quantum yield, photocatalytic space-time yield and light energy consumption. The results showed that the FPMR based on submerged ceramic membrane had a higher efficiency than other reported photocatalytic reactors. The comparison of the different modes of operation revealed that the closed loop FPMR is most efficient with regard to light energy con-sumption. Finally, this work discusses the up-scaling of FPMRs for industrial applications and proposes a solution, which can e.g. be employed for wastewater treatment or CO2 conversion.:Abstract iii Kurzfassung v Acknowledgment vii Contents ix Nomenclature xiii 1 Introduction 1 1.1 Motivation 1 1.2 Aim and objectives of the work 3 1.3 Thesis outline 3 2 Heterogeneous photocatalytic reactors 5 2.1 Introduction to photocatalysis 5 2.2 Processes in heterogeneous photocatalysis 6 2.2.1 Optical phenomena 7 2.2.2 Mass transfer 8 2.2.3 Adsorption and desorption 9 2.2.4 Photocatalytic reactions 10 2.2.5 Factors affecting heterogeneous photocatalysis 12 2.3 Photocatalytic reactor systems towards water treatment 16 2.3.1 Introduction to photocatalytic reactors 16 2.3.2 Development of photocatalytic reactor designs 17 2.3.3 Quantitative criteria for evaluating photocatalytic reactor designs 21 2.4 Cake layer formation in membrane microfiltration 22 2.4.1 Suspension preparation 22 2.4.2 Cake layer formation 23 2.5 Fluid flow through a fixed bed of particles 25 2.5.1 Pressure drop through a fixed-bed 25 2.5.2 Liquid-solid mass transfer correlation in fixed-bed 25 3 Concept and mathematical modelling of FPMRs 29 3.1 Concept of fixed-bed photocatalytic membrane reactors 29 3.2 Modelling of fixed-bed photocatalytic membrane reactors 31 3.3 Model sensitivity analysis 37 3.4 Chapter summary 39 4 FPMR realised with flat sheet polymeric membrane 41 4.1 Introduction 41 4.2 Materials and set-up 41 4.2.1 Materials 41 4.2.2 Experimental set-up 43 4.3 Experiments and methods 48 4.3.1 Formation of fixed-bed photocatalytic membrane 48 4.3.2 Reactor performance 50 4.3.3 Parameters study and model verification 53 4.3.4 Catalyst layer characterisation 56 4.3.5 Measurement and evaluation of photocatalytic activity of FPM 59 4.4 Results and model verification 60 4.4.1 Reactor performance 60 4.4.2 Influence parameters 71 4.4.3 Model verification 79 5 FPMR realised with submerged ceramic membrane 92 5.1 Introduction 92 5.2 Materials and reactor set-up 93 5.2.1 Reactor set-up 93 5.2.2 Chemicals 97 5.3 Experiments and methods 97 5.3.1 Formation of fixed-bed photocatalytic membranes 97 5.3.2 Photocatalytic performance 97 5.3.3 Parameter study 98 5.3.4 Reactor model for calculating reaction rate constant of FPM 99 5.3.5 Comparison of different reactor schemes 102 5.4 Results and discussions 105 5.4.1 Reactor performance 105 5.4.2 Consistency of CPMR and LPMR data 107 5.4.3 Influence of catalyst loading 108 5.4.4 Influence of permeate flux and light intensity 109 5.4.5 Reactor efficiency 111 5.4.6 Comparison of different reactor schemes 113 5.5 Proposed up-scaled FPMR systems 113 5.6 Concluding remarks 116 6 Conclusion and outlook 118 6.1 Summary of thesis contributions 118 6.2 Discussion and outlook 120 References 122 List of Figures 134 List of Tables 138 Appendix A Calibration 139 A.1 Distribution of light intensity on the surface of catalyst layer 139 A.2 Concentration and absorbance of diclofenac 141 A.3 TOC concentration and electrical conductivity of oxalic acid 141 A.4 Concentration and absorbance of methylene blue 142 Appendix B Mathematical modelling 143 B.1 Influence of axial dispersion on the reaction rate 143 B.2 Special case 146 Appendix C Comparison the photocatalytic activity of TiO2 and ZnO 147 Appendix D Mathematical validation of model for LPMR and CPMR 148 D.1 Model for LPMR (cf. Eq. (5 12)):148 D.2 Model for CPMR (cf. Eq. (5 17)) 149 Appendix E Particle size distribution 15

Proactive and Dynamic Task Scheduling in Fog-cloud Environment

Fog computing was introduced for the first time by Cisco in 2012. Since then, there has been a great number of studies on fog computing, in which vacant and free-of-charge computing resources in local networks provide low-latency services to end devices. Even though traditional architecture with scalable and powerful central servers in cloud can accommodate those tasks, it is costly to allocate resources in cloud to execute all those tasks. In addition, it falls short of satisfying Quality of Service (QoS) requirements in terms of waiting time because of long distance communication between servers and user end devices. In this thesis, we discuss dynamic scheduling problem in fog-cloud collaboration environment for real-time applications when QoS is strict and when an answer is useless if the corresponding application finishes its execution after a pre-defined deadline. By taking into account an admission control procedure to grant only requests whose deadline requirements are feasible with respect to the available resources in the network, we study a proactive scenario using different strategies to calculate schedules and to assign resources, within the admission control procedure to accommodate an incoming request. Then, we propose our heuristic with four variants corresponding to four different strategies, with the adjustment of a trade-off cost-makespan factor in an utility function. When evaluating performance with some baseline methods in such proactive scenario, the numerical results show that our variants can meet deadline requirements for more applications while exploiting more efficiently the resources in the fog layer and being charged less for using cloud. Keywords: fog computing, cloud computing, dynamic scheduling, real-time scheduling, task scheduling, workflow applications, DAG, QoS requirements, heterogeneous systems

Study on fabrication of nanofibers with multifunctions for textile, water filtration, and biomedicine (濾過および生物医学の為の多機能ナノファイバー製造に関する研究)

信州大学(Shinshu university)博士（工学）ThesisPHAN DUY NAM. Study on fabrication of nanofibers with multifunctions for textile, water filtration, and biomedicine　(濾過および生物医学の為の多機能ナノファイバー製造に関する研究)【要旨】. 信州大学, 2020, 博士論文. 博士（工学）, 甲第724号, 令和02年03月20日授与.doctoral thesi

Reparations to Victims of Gross Human Rights Violations: The Case of Cambodia

The world community has introduced various legal instruments regarding reparations for gross violations of human rights. In Cambodia, however, reparations for those seriously and systematically deprived of their rights by the Khmer Rouge regime remain an unresolved issue, even after the establishment of the Extraordinary Chambers in the Courts of Cambodia for the Prosecution of Crimes Committed during the Period of Democratic Kampuchea. In so complicated a case as Cambodia\u27s, there are many questions regarding the reparations issue that are left unanswered. This Article examines the issue and offers some recommendations for a feasible and effective reparation program for the Khmer Rouge\u27s victims