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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Controlling Depth of Cellular Quiescence by an Rb-E2F Network Switch

Kwon, Jungeun Sarah, Everetts, Nicholas J., Wang, Xia, Wang, Weikang, Della Croce, Kimiko, Xing, Jianhua, Yao, Guang 09 1900 (has links)
Quiescence is a non-proliferative cellular state that is critical to tissue repair and regeneration. Although often described as the G0 phase, quiescence is not a single homogeneous state. As cells remain quiescent for longer durations, they move progressively deeper and display a reduced sensitivity to growth signals. Deep quiescent cells, unlike senescent cells, can still re-enter the cell cycle under physiological conditions. Mechanisms controlling quiescence depth are poorly understood, representing a currently underappreciated layer of complexity in growth control. Here, we show that the activation threshold of a Retinoblastoma (Rb)-E2F network switch controls quiescence depth. Particularly, deeper quiescent cells feature a higher E2F-switching threshold and exhibit a delayed traverse through the restriction point (R-point). We further show that different components of the Rb-E2F network can be experimentally perturbed, following computer model predictions, to coarse-or fine-tune the E2F-switching threshold and drive cells into varying quiescence depths.
42

Aplikace fuzzy logiky při hodnocení dodavatelů firmy / The Application of Fuzzy Logic for Rating of Suppliers for the Firm

Zegzulka, Ivo January 2014 (has links)
This thesis deals with the design of fuzzy system that can evaluate supplier of spare parts for service. The result should be applicable to a company Iveta Šťastníková - car and tire service. Primarily it should simplify operations associated with the selection of appropriate spare parts, tools and other equipment needed to operate with car service station. First, we introduce the theoretical basis for the paper, and then we go to the present state and the analysis itself. The result is a proposed solution which should correspond to the needs of the owner.
43

Numerický model řídicí jednotky spalovacího motoru / Numerical Model of Engine Control Unit

Křepelka, Jan January 2014 (has links)
Master’s thesis deals with issues of controlling the amount of fuel injected by the control unit. Model of four-cylinder engine and computational model of control unit were constructed in the simulation software Lotus Engine Simulation. Then was made model checking of the control unit by simulation two transients (acceleration and shifting). In conclusion was made application a created model on the New European Driving Cycle (NEDC) and appropriately evaluated and processed the results of this simulation.
44

Realizace komponentového modelu DEECo a jeho aplikace v simulacích virtuálních světů / Reification of the DEECo component model and its application in virtual-world simulations

Forch, Jan January 2013 (has links)
In the domain of dynamically evolving distributed systems composed of autonomous and (self-) adaptive components, the task of systematically managing the design complexity of their communication and composition is a pressing issue. This stems from the dynamic nature of such systems, where components and their bindings may appear and disappear without anticipation. As one way of addressing the challenge, [15] proposes a new component model (called DEECo), which features separation of concerns via a mechanism of dynamic implicit bindings with implicit communication. This leads to introduction of autonomous components and their dynamic interaction groups (called ensembles). The goal of the thesis is to reify the DEECo concepts and paradigms in a Java-based implementation connected to a simulation of a virtual world. As such, the thesis should provide a platform for experimentation with DEECo-based applications.
45

Modeling of plant in vitro cultures – overview and estimation of biotechnological processes

Maschke, Rüdiger W., Geipel, Katja, Bley, Thomas January 2015 (has links)
Plant cell and tissue cultivations are of growing interest for the production of structurally complex and expensive plant-derived products, especially in pharmaceutical production. Problems with up-scaling, low yields and high-priced process conditions result in an increased demand for models to provide comprehension, simulation, and optimization of production processes. In the last 25 years, many models have evolved in plant biotechnology; the majority of them are specialized models for a few selected products or nutritional conditions. In this article we review, delineate, and discuss the concepts and characteristics of the most commonly used models. Therefore, the authors focus on models for plant suspension and submerged hairy root cultures. The article includes a short overview of modeling and mathematics and integrated parameters, as well as the application scope for each model. The review is meant to help researchers better understand and utilize the numerous models published for plant cultures, and to select the most suitable model for their purposes.
46

Automatizace řešení zásobní funkce vodohospodářské soustavy / Automation Solution of Storage Function of Water Management System

Menšík, Pavel January 2012 (has links)
The impact of climate changes on various sectors of human activity and preparation of mitigation and adaptation measures are becoming an important subject of global policy, thus also the policy of the Czech Republic. According to the research results, the impact of climate changes on minimum discharges is very significant and indicates a threat to storage function of water sources, without adequate accumulation for period of drought. One of the ways of preventing or completely avoiding the appearance of these problems is the construction of new reservoirs or the re-evaluation of the size of the storage and protective capacity of existing reservoirs. In relation to climate changes and their impact on the water yield there is a growing need for the participation of operative control progressive methods of reservoir storage function today. The dissertation thesis is aimed at storage function of water management system. Aim of the dissertation work is to create program with graphical user interface, which allows solving the storage function of water management system. Program allows automatically set up optimization and simulation model of any water supply system and solve of optimal control and optimal development of the water supply system. The program was verified on the selected water supply subsystem.
47

Properties of Hurdle Negative Binomial Models for Zero-Inflated and Overdispersed Count data

Bhaktha, Nivedita January 2018 (has links)
No description available.
48

Natural hydrate-bearing sediments: Physical properties and characterization techniques

Dai, Sheng 27 August 2014 (has links)
An extensive amount of natural gas trapped in the subsurface is found as methane hydrate. A fundamental understanding of natural hydrate-bearing sediments is required to engineer production strategies and to assess the risks hydrates pose to global climate change and large-scale seafloor destabilization. This thesis reports fundamental studies on hydrate nucleation, morphology and the evolution of unsaturation during dissociation, followed by additional studies on sampling and pressure core testing. Hydrate nucleation is favored on mineral surfaces and it is often triggered by mechanical vibration. Continued hydrate crystal growth within sediments is governed by capillary and skeletal forces; hence, the characteristic particle size d10 and the sediment burial depth determine hydrate morphologies in natural sediments. In aged hydrate-bearing sand, Ostwald ripening leads to patchy hydrate formation; the stiffness approaches to the lower bound at low hydrate saturation and the upper bound at high hydrate saturation. Hydrate saturation and pore habit alter the pore size variability and interconnectivity, and change the water retention curve in hydrate-bearing sediments. The physical properties of hydrate-bearing sediments are determined by the state of stress, porosity, and hydrate saturation. Furthermore, hydrate stability requires sampling, handling, and testing under in situ pressure, temperature, and stress conditions. Therefore, the laboratory characterization of natural hydrate-bearing sediments faces inherent sampling disturbances caused by changes in stress and strain as well as transient pressure and temperature changes that affect hydrate stability. While pressure core technology offers unprecedented opportunities for the study of hydrate-bearing sediments, careful data interpretation must recognize its inherent limitations.
49

Moderní metody a nástroje pro podporu manažerského rozhodování / Modern Methods and Tools to Support Managerial Decision

Krčil, Jakub January 2012 (has links)
This master's thesis is focused on modern methods and tools to support managerial decision-making. The first part of this thesis introduces the basic characteristics related to the management and managerial decision-making that are subsequently extended to the area of modeling, simulation, optimization and multi-criteria decision making. It also outlines the relationship between the managerial decision-making tasks. The second part introduces practical examples which show the connection of these areas. Specifically, they are a colony of ants, traveling salesman problem, a tool AnyLogic, analytic hierarchy process and simulation HealthBound. The thesis is further supplemented by an appropriate software tools to support multi-criteria decision making.
50

Tvorba a estimace modelu malé vodní elektrárny v programu PSCAD / Creation and estimation of small hydro power plant model in PSCAD

Razyapova, Aygul January 2018 (has links)
This thesis focused on creating a model of a small hydropower plant model (SHPP) and a part of the electricity network in the simulation software "PSCAD" (basing on real sources). The model will be specified on the basis of the data obtained from the measurements to correspond with the real equipment.

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