93 research outputs found

    On incorporating uncertainty analysis in abstract building performance simulation tools

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    Abstract Building Performance Simulation (BPS) is a powerful measure to educate the building design process. However, its use in practice is too large extends limited to the detailed design stage dedicated to the code compliance analysis of worked out design proposals. BPS is not much used to support the conceptual design stage (CDS). To date BPS -tools are regarded as pure analysis tools, which do not provide design information. It is hypothesized that, when integrating uncertainty analysis techniques to existing BPStools (incremental research approach) valuable design information can be provided. The paper gives an update on the process to integrate an uncertainty assessment capability to a tool specifically developed to support the conceptual design stage. The resulting prototype should be capable of providing information about the deviation of specific design parameters (simulation output) based on the uncertainties of the building concept specification (simulation input). In addition to the total uncertainties, the results also indicate sensitivities of the design parameters as a result of the concept specification variation. This paper describes an approach to add extra-capabilities to legacy simulation tools and presents a comparison of uncertainties and total sensitivities calculated with one detailed design analysis (DDA) tool, IES, and one conceptual design analysis (CDA) tool , LEA. The main focus was herby the representation of material properties and its impact on the model uncertainty

    Application of the Methodology of Communication Skills Training for Employees of Hotel Companies, Based on Immersion into the Virtual World

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    This paper describes a research study of communication skills training for future hotel workers in an immersive environment. The research team developed a model of the hotel reception in a virtual environment, and proposed a methodology for three-phase training. The research involved 56 testers who provided detailed feedback. To improve the communication skills of the participants, it is necessary to repeat the simulations and analyze the individual aspects of the communication in depth

    Lanthanide(III) Complexes of Novel Mixed Carboxylic-Phosphorus Acid Derivatives of Diethylenetriamine: A Step towards More Efficient MRI Contrast Agents

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    Three novel phosphorus-containing analogues of H5DTPA (DTPA = diethylenetriaminepentaacetate) were synthesised (H6L1, H5L2, H5L3). These compounds have a -CH2-P(O)(OH)-R function (R = OH, Ph, CH2NBn2) attached to the central nitrogen atom of the diethylenetriamine backbone. An NMR study reveals that these ligands bind to lanthanide(III) ions in an octadentate fashion through the three nitrogen atoms, a P-O oxygen atom and four carboxylate oxygen atoms. The complexed ligand occurs in several enantiomeric forms due to the chirality of the central nitrogen atom and the phosphorus atom upon coordination. All lanthanide complexes studied have one coordinated water molecule. The residence times (tau) of the coordinated water molecules in the gadolinium(III) complexes of H6L1 and H5L2 are 88 and 92 ns, respectively, which are close to the optimum. This is particularly important upon covalent and noncovalent attachment of these Gd3+ chelates to polymers. The relaxivity of the complexes studied is further enhanced by the presence of at least two water molecules in the second coordination sphere of the Gd3+ ion, which are probably bound to the phosphonate/phosphinate moiety by hydrogen bonds. The complex [Gd(L3)(H2O)]2- shows strong binding ability to HSA, and the adduct has a relaxivity comparable to MS-325 (40 s-1 mM-1 at 40 MHz, 37 °C) even though it has a less favourable tauM value (685 ns). Transmetallation experiments with Zn2+ indicate that the complexes have a kinetic stability that is comparable to - or better than - those of [Gd(dtpa)(H2O)]2- and [Gd(dtpa-bma)(H2O)]

    Tissue-Specific T2* Biomarkers in Patellar Tendinopathy by Subregional Quantification Using 3D Ultrashort Echo Time MRI

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    Background: Quantitative MRI of patellar tendinopathy (PT) can be challenging due to spatial variation of T2* relaxation times. Purpose: 1) To compare T2* quantification using a standard approach with analysis in specific tissue compartments of the patellar tendon. 2) To evaluate test–retest reliability of different methods for fitting ultrashort echo time (UTE)-relaxometry data. Study Type: Prospective. Subjects: Sixty-five athletes with PT. Field Strength/Sequence: 3D UTE scans covering the patellar tendon were acquired using a 3.0T scanner and a 16-channel surface coil. Assessment: Voxelwise median T2* was quantified with monoexponential, fractional-order, and biexponential fitting. We applied two methods for T2* analysis: first, a standard approach by analyzing all voxels covering the proximal patellar tendon. Second, within subregions of the patellar tendon, by using thresholds on biexponential fitting parameter percentage short T2* (0–30% for mostly long T2*, 30–60% for mixed T2*, and 60–100% for mostly short T2*). Statistical Tests: Average test–retest reliability was assessed in three athletes using coefficients-of-variation (CV) and coefficients-of-repeatability (CR). Results: With standard image analysis, we found a median [interquartile range, IQR] monoexponential T2* of 6.43 msec [4.32–8.55] and fractional order T2* 4.39 msec [3.06–5.78]. The percentage of short T2* components was 52.9% [35.5–69.6]. Subregional monoexponential T2* was 13.78 msec [12.11–16.46], 7.65 msec [6.49–8.61], and 3.05 msec [2.52–3.60] and fractional order T2* 11.82 msec [10.09–14.44], 5.14 msec [4.25–5.96], and 2.19 msec [1.82–2.64] for 0–30%, 30–60%, and 60–100% short T2*, respectively. Biexponential component short T2* was 1.693 msec [1.417–2.003] for tissue with mostly short T2* and long T2* of 15.79 msec [13.47–18.61] for mostly long T2*. The average CR (CV) was 2 msec (15%), 2 msec (19%) and 10% (22%) for monoexponential, fractional order and percentage short T2*, respectively. Data Conclusion: Patellar tendinopathy is characterized by regional variability in binding states of water. Quantitative multicompartment T2* analysis in PT can be facilitated using a voxel selection method based on using biexponential fitting parameters. Level of Evidence: 1. Technical Efficacy Stage: 1

    Blood perfusion of patellar bone measured by dynamic contrast-enhanced MRI in patients with patellofemoral pain: A case-control study

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    Background: Altered perfusion might play an important role in the pathophysiology of patellofemoral pain (PFP), a common knee complaint with unclear pathophysiology. Purpose: To investigate differences in dynamic contrast-enhanced (DCE)-MRI perfusion parameters between patients with PFP and healthy control subjects. Population/Subjects/Phantom/Specimen

    Clinically Translatable Cell Tracking and Quantification by MRI in Cartilage Repair Using Superparamagnetic Iron Oxides

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    Background: Articular cartilage has very limited intrinsic regenerative capacity, making cell-based therapy a tempting approach for cartilage repair. Cell tracking can be a major step towards unraveling and improving the repair process of these therapies. We studied superparamagnetic iron oxides (SPIO) for labeling human bone marrow-derived mesenchymal stem cells (hBMSCs) regarding effectivity, cell viability, long term metabolic cell activity, chondrogenic differentiation and hBMSC secretion profile. We additionally examined the capacity of synovial cells to endocytose SPIO from dead, labeled cells, together with the use of magnetic resonance imaging (MRI) for intra-articular visualization and quantification of SPIO labeled cells. Methodology/Prinicipal Findings: Efficacy and various safety aspects of SPIO cell labeling were determined using appropriate assays. Synovial SPIO re-uptake was investigated in vitro by co-labeling cells with SPIO and green fluorescent protein (GFP). MRI experiments were performed on a clinical 3.0T MRI scanner. Two cell-based cartilage repair techniques were mimicked for evaluating MRI traceability of labeled cells: intra-articular cell injection and cell implantation in cartilage defects. Cells were applied ex vivo or in vitro in an intra-articular environment and immediately scanned. SPIO labeling was effective and did not impair any of the studied safety aspects, including hBMSC secretion profile. SPIO from dead, labeled cells could be taken up by synovial cells. Both injected and implanted SPIO-labeled cells could accurately be visualized by MRI in a clinically relevant sized joint model using clinically applied cell doses. Finally, we quantified the amount of labeled cells seeded in cartilage defects using MR-based relaxometry. Conclusions: SPIO labeling appears to be safe without influencing cell behavior. SPIO labeled cells can be visualized in an intra-articular environment and quantified when seeded in cartilage defects.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin

    Analysis and suggestions for business development of a company in e-commerce

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    Práce se zabývá strategickou analýzou a návrhem možností růstu pro společnost působící na českém e-commerce. Cílem je vypracování strategické analýzy a návrhu možnosti růstu firmy. V teoretické části jsou představeny pojmy a koncepty spojené s podnikovou strategií a se strategickým plánovacím cyklem, jenž zahrnuje externí i interní analýzu. Součástí je popis výzkumných metod, o které se praktická část opírá, a sice kvalitativní metoda hloubkových rozhovorů a kvantitativní metoda dotazníkového šetření. Praktická část se nejdříve zabývá strategickou analýzou. Po analýze vnějšího a vnitřního prostředí firmy jsou vygenerovány možné příležitosti růstu, ze kterých autor vybere tu nejvhodnější s doporučenými akčními kroky. Dokument slouží širšímu vedení firmy, do kterého patří i autor práce, aby se management mohl lépe rozhodnout, kam alokovat svou pozornost.The thesis deals with strategic analysis and proposal of growth opportunities for a company operating on Czech e-commerce. The aim is to elaborate strategic analysis and suggestion of growth possibilities of the company. The theoretical part introduces the concepts and concepts associated with business strategy and strategic planning cycle, which includes both external and internal analysis. A part of the thesis is a description of the research methods on which the practical part is based, namely the qualitative method of in-depth interviews and the quantitative method of questionnaire survey. The practical part deals first with the strategic analysis. After analyzing the external and internal environment of the company are generated possible growth opportunities, from which the author selects the most appropriate with recommended action steps. The document serves the wider management of the company, which includes the author of the work, so management can better decide where to allocate its attention

    Numerical solution of physical problems leading to the system of PDEs by the Finite Element Method - an introduction

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    Astronomical Institute of Charles UniversityAstronomický ústav UKMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

    Business plan: Uniseeker -- find your university

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    The aim of the bachelor thesis is to create a business plan for a startup called Uniseeker. The plan is to create a global platform, which helps students to find the right university abroad. The theoretical part describes processing of the business plan, with a focus on creating a business model and validating entrepreneur´s hypotheses. The practical part contains the business plan using Lean Canvas tool for creation of business model. Furthermore, the practical part deals with a market analysis, which is mainly oriented on problems and needs of potential users and customers. Results of the survey are included as well as data of student migration in the world
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