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Research of thermal processes in industrial premises with energy-saving technologies of heating

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Diagnostyka 2017年第2期18卷 43-49页

作者： Gumen, Olena Spodyniuk, Nadiia Ulewicz, Malgorzata Martyn, Yevgen National Technical University of Ukraine Igor Sikorsky Kyiv Polytechnic Institute Department of Descriptive Geometry Engineering and Computer Graphics Peremohy pr. 37 Kyiv03056 Ukraine Lviv Polytechnic National University Department of Heat and Gas Supply and Ventilation St. Bandery 12 Lviv - 1379013 Ukraine Czestochowa University of Technology Department of General Building Engineering and Building Physics Akademicka 3 Czestochowa42-201 Poland Lviv State University of Life Safety Department of Project Management Information Technologies and Telecommunications Kleparivska 35 Lviv - 0779007 Ukraine

The article presents the results of experimental research of thermal processes in industrial premises with energy-saving technologies of heating and their analysis by geometric modeling tools and graphic computer technologies. The effectiveness of using the method of forced feeding of air heated by infrared emitter involving compromise graphical optimization was analyzed by geometric way.

关键词： Geometry

computer-aided position planning of miniplates to treat facial bone defects

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arXiv 2017年

作者： Egger, Jan Wallner, Jürgen Gall, Markus Chen, Xiaojun Schwenzer-Zimmerer, Katja Reinbacher, Knut Schmalstieg, Dieter Institute for Computer Graphics and Vision Faculty of Computer Science and Biomedical Engineering Graz University of Technology Graz Austria BioTechMed-Graz Graz Austria Department of Oral & Maxillofacial Surgery Medical University of Graz Graz Styria Austria Institute of Biomedical Manufacturing and Life Quality Engineering School of Mechanical Engineering Shanghai Jiao Tong University Shanghai China

In this contribution, a software system for computer-aided position planning of miniplates to treat facial bone defects is proposed. The intra-operatively used bone plates have to be passively adapted on the underlying bone contours for adequate bone fragment stabilization. However, this procedure can lead to frequent intra-operatively performed material readjustments especially in complex surgical cases. Our approach is able to fit a selection of common implant models on the surgeon’s desired position in a 3D computer model. This happens with respect to the surrounding anatomical structures, always including the possibility of adjusting both the direction and the position of the used osteosynthesis material. By using the proposed software, surgeons are able to pre-plan the out coming implant in its form and morphology with the aid of a computer-visualized model within a few minutes. Further, the resulting model can be stored in STL file format, the commonly used format for 3D printing. Using this technology, surgeons are able to print the virtual generated implant, or create an individually designed bending tool. This method leads to adapted osteosynthesis materials according to the surrounding anatomy and requires further a minimum amount of money and time. Copyright © 2017, The Authors. All rights reserved.

关键词： Defects

Clinical evaluation of semi-automatic opensource algorithmic software segmentation of the mandibular bone: Practical feasibility and assessment of a new course of action

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arXiv 2018年

作者： Wallner, Jürgen Hochegger, Kerstin Chen, Xiaojun Mischak, Irene Reinbacher, Knut Pau, Mauro Zrnc, Tomislav Schwenzer-Zimmerer, Katja Zemann, Wolfgang Schmalstieg, Dieter Egger, Jan Department of Oral & Maxillofacial Surgery Medical University of Graz Auenbruggerplatz 5/1 Graz Austria Laboratory Graz Austria Institute for Computer Graphics and Vision Graz University of Technology Inffeldgasse 16c/II Graz Austria School of Mechanical Engineering Shanghai Jiao Tong University Shanghai China Department of Dental Medicine and Oral Health Medical University of Graz Billrothgasse 4 Graz Austria BioTechMed-Graz Krenngasse 37/1 Graz Austria

Introduction: computer assisted technologies based on algorithmic software segmentation are an increasing topic of interest in complex surgical cases. However-due to functional instability, time consuming software processes, personnel resources or licensed-based financial costs many segmentation processes are often outsourced from clinical centers to third parties and the industry. Therefore, the aim of this trial was to assess the practical feasibility of an easy available, functional stable and licensed-free segmentation approach to be used in the clinical practice. Material and methods: In this retrospective, randomized, controlled trail the accuracy and accordance of the opensource based segmentation algorithm GrowCut was assessed through the comparison to the manually generated ground truth of the same anatomy using 10 CT lower jaw data-sets from the clinical routine. Assessment parameters were the segmentation time, the volume, the voxel number, the Dice Score and the Hausdorff distance. Results: Overall semi-automatic GrowCut segmentation times were about one minute. Mean Dice Score values of over 85% and Hausdorff Distances below 33.5 voxel could be achieved between the algorithmic GrowCut-based segmentations and the manual generated ground truth schemes. Statistical differences between the assessment parameters were not significant (p0.94) for any of the comparison made between the two groups. Discussion: Complete functional stable and time saving segmentations with high accuracy and high positive correlation could be performed by the presented interactive open-source based approach. In the cranio-maxillofacial complex the used method could represent an algorithmic alternative for image-based segmentation in the clinical practice for e.g. surgical treatment planning or visualization of postoperative results and offers several advantages. Due to an open-source basis the used method could be further developed by other groups or specialists. Systematic compari

关键词： Geometry

Analysis of normal human retinal vascular network architecture using multifractal geometry

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International Journal of Ophthalmology(English edition) 2017年第3期10卷 434-438页

作者： Stefan Talu Sebastian Stach Dan Mihai Calugaru Carmen Alina Lupascu Simona Delia Nicoara Discipline of Descriptive Geometry and Engineering Graphics Department of AETFaculty of Mechanical EngineeringTechnical University of Cluj-Napoca103-105 B-dul Muncii St.Cluj-Napoca 400641ClujRomania Department of Biomedical Computer Systems Institute of InformaticsFaculty of Computer Science and Materials ScienceUniversity of SilesiaBedzifiska 3941-205 SosnowiecPoland Discipline of Ophthalmology Department of Surgical Speci-alties and Medical ImagingFaculty of Medicine'Iuliu Halie-ganu'University of Medicine and Pharmacy Cluj-Napoca8 Victor Babes St.Cluj-Napoca 400012ClujRomania Department of Mathematics and Informatics University of PalermoVia Archirafi 34Palermo 90123Italy

AIM：To apply the multifractal analysis method as a quantitative approach to a comprehensive description of the microvascular network architecture of the normal human ***：Fifty volunteers were enrolled in this study in the Ophthalmological Clinic of Cluj-Napoca,Romania,between January 2012 and January 2014. A set of 100 segmented and skeletonised human retinal images,corresponding to normal states of the retina were studied. An automatic unsupervised method for retinal vessel segmentation was applied before multifractal analysis. The multifractal analysis of digital retinal images was made with computer algorithms,applying the standard boxcounting method. Statistical analyses were performed using the Graph Pad In Stat ***：The architecture of normal human retinal microvascular network was able to be described using the multifractal geometry. The average of generalized dimensions（D_q）for q=0,1,2,the width of the multifractal spectrum（Δα=α_（max）-α_（min））and the spectrum arms＇ heights difference（│Δf│）of the normal images were expressed as mean±standard deviation（SD）：for segmented versions,D_0=1.7014±0.0057; D_1=1.6507±0.0058; D_2=1.5772±0.0059; Δα=0.92441±0.0085; │Δf│= 0.1453±0.0051; for skeletonised versions,D_0=1.6303±0.0051; D_1=1.6012±0.0059; D_2=1.5531± 0.0058; Δα=0.65032±0.0162; │Δf│= 0.0238±0.0161. The average of generalized dimensions（D_q）for q=0,1,2,the width of the multifractal spectrum（Δα）and the spectrum arms＇ heights difference（│Δf│）of the segmented versions was slightly greater than the skeletonised ***：The multifractal analysis of fundus photographs may be used as a quantitative parameter for the evaluation of the complex three-dimensional structure of the retinal microvasculature as a potential marker for early detection of topological changes associated with retinal diseases.

关键词： generalized dimensions multifractal retinal vessel segmentation retinal image analysis retinal microvasculature standard box-counting method

Inertial proximal alternating linearized minimization (iPALM) for nonconvex and nonsmooth problems

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arXiv 2017年

作者： Pock, Thomas Sabach, Shoham Institute of Computer Graphics and Vision Graz University of Technology Graz8010 Austria Digital Safety and Security Department Ait Austrian Institute of Technology GmbH Vienna1220 Austria Department of Industrial Engineering and Management Technion-Israel Institute of Technology Haifa3200003 Israel

In this paper we study nonconvex and nonsmooth optimization problems with semi-algebraic data, where the variables vector is split into several blocks of variables. The problem consists of one smooth function of the entire variables vector and the sum of nonsmooth functions for each block separately. We analyze an inertial version of the Proximal Alternating Linearized Minimization (PALM) algorithm and prove its global convergence to a critical point of the objective function at hand. We illustrate our theoretical findings by presenting numerical experiments on blind image deconvolution, on sparse non-negative matrix factorization and on dictionary learning, which demonstrate the viability and effectiveness of the proposed method. Copyright © 2017, The Authors. All rights reserved.

关键词： Linearization

Interactive reconstructions of cranial 3D implants under MeVisLab as an alternative to commercial planning software

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arXiv 2017年

作者： Egger, Jan Gall, Markus Tax, Alois Ücal, Muammer Zefferer, Ulrike Li, Xing von Campe, Gord Schäfer, Ute Schmalstieg, Dieter Chen, Xiaojun Institute for Computer Graphics and Vision Faculty of Computer Science and Biomedical Engineering Graz University of Technology Inffeldgasse 16 Graz Austria BioTechMed-Graz Krenngasse 37/1 Graz Austria Department of Neurosurgery Medical University of Graz Auenbruggerplatz 29 Graz Austria Institute of Biomedical Manufacturing and Life Quality Engineering School of Mechanical Engineering Shanghai Jiao Tong University China

In this publication, the interactive planning and reconstruction of cranial 3D Implants under the medical prototyping platform MeVisLab as alternative to commercial planning software is introduced. In doing so, a MeVisLab prototype consisting of a customized data-flow network and an own C++ module was set up. As a result, the computer-Aided Design (CAD) software prototype guides a user through the whole workflow to generate an implant. Therefore, the workflow begins with loading and mirroring the patients head for an initial curvature of the implant. Then, the user can perform an additional Laplacian smoothing, followed by a Delaunay triangulation. The result is an aesthetic looking and well-fitting 3D implant, which can be stored in a CAD file format, e.g. STereoLithography (STL), for 3D printing. The 3D printed implant can finally be used for an in-depth pre-surgical evaluation or even as a real implant for the patient. In a nutshell, our research and development shows that a customized MeVisLab software prototype can be used as an alternative to complex commercial planning software, which may also not be available in every clinic. Finally, not to conform ourselves directly to available commercial software and look for other options that might improve the workflow. Copyright © 2017, The Authors. All rights reserved.

关键词： Software prototyping

Modular retrofitting solution of buildings based on 3D scanning

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Procedia engineering 2017年 205卷 160-166页

作者： Anatolijs Borodinecs Jurgis Zemitis Modris Dobelis Maris Kalinka Aleksejs Prozuments Kristīne Šteinerte Institute of Heat Gas and Water Technology Faculty of Civil Engineering of Riga Tech-nical University Riga Latvia Department of Computer Aided Engineering Graphics Faculty of Civil Engineering of Riga Technical University Riga Latvia Department of Geomatics Faculty of Civil Engineering of Riga Technical University Riga Latvia Project development department of Riga Technical University Kipsalas str. 6A Riga Latvia

Building stock is one of the crucial energy consumers in Europe. The majority of the European residential and public buildings were constructed after the Second World War. The external building envelope of these buildings has very poor thermal insulation properties with regards to modern requirements. There are several well known building retrofitting technologies such as rendered and double facades. These retrofitting technologies require large amount of on-site human working mounts. However, there might be significant limitations in mounting processes of the unclassified buildings such as prisons, military buildings and other buildings with specific safety requirements. In scope of this article the benefits of modular retrofitting solutions are taken into consideration. The paper presents the results of the architectural project development specifics as well as selection of the optimal modular panel layout, integration of existing communication and modular panels junctions solutions. This paper is prepared in the scope of work done within the European Regional Development Fund project “NEARLY ZERO ENERGY SOLUTIONS FOR UNCLASSIFIED BUILDINGS”.

关键词： modular retrofitting 3D scanning BIM thermal bridges

On a critical artifact in the quantum yield methodology

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arXiv 2018年

作者： van Dam, Bart Bruhn, Benjamin Kondapaneni, Ivo Dohnal, Gejza Wilkie, Alexander Křivaánek, Jaroslav Valenta, Jan Mudde, Yvo D. Schall, Peter Dohnalová, Kateřina University of Amsterdam Institute of Physics Science Park 904 Amsterdam1098 XH Netherlands Computer Graphics Group KSVI Faculty of Mathematics and Physics Charles University Malostranské náměstí 25 Prague 1CZ-11800 Czech Republic Czech Technical University in Prague Faculty of Mechanical Engineering Karlovo náměstí 13 Prague 2121 35 Czech Republic Department of Chemical Physics and Optics Faculty of Mathematics and Physics Charles University Ke Karlovu 3 Prague 2CZ-121 16 Czech Republic

For the development and optimization of novel light emitting materials, such as fluorescent proteins, dyes and semiconductor quantum dots (QDs), a reliable and robust analysis of the emission efficiency is crucial. The emission efficiency is typically quantified by the photoluminescence quantum yield (QY), defined by the ratio of emitted to absorbed photons. We show that this methodology suffers from a flaw that leads to underestimated QY values, presenting as a’parasitic absorption’. This effect has not been described and/or corrected for in literature and is present already under common experimental conditions, therefore, it is highly relevant for a number of published studies. To correct for this effect, we propose a modification to the methodology and a correction procedure. Copyright © 2018, The Authors. All rights reserved.

关键词： Quantum yield

Development of a computer-aided design software for dental splint in orthognathic surgery

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arXiv 2017年

作者： Chen, Xiaojun Li, Xing Xu, Lu Sun, Yi Politis, Constantinus Egger, Jan Institute of Biomedical Manufacturing and Life Quality Engineering State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University Shanghai China OMFS IMPATH Research Group Department of Imaging and Pathology Faculty of Medicine KU Leuven Leuven Belgium Department of Oral and Maxillofacial Surgery University Hospitals Leuven Leuven Belgium Faculty of Computer Science and Biomedical Engineering Institute for Computer Graphics and Vision Graz University of Technology Graz Austria BioTechMed-Graz Graz Austria

In the orthognathic surgery, dental splints are important and necessary to help the surgeon reposition the maxilla or mandible. However, the traditional methods of manual design of dental splints are difficult and time-consuming. The research on computer-aided design software for dental splints is rarely reported. Our purpose is to develop a novel special software named EasySplint to design the dental splints conveniently and efficiently. The design can be divided into two steps, which are the generation of initial splint base and the Boolean operation between it and the maxilla-mandibular model. The initial splint base is formed by ruled surfaces reconstructed using the manually picked points. Then, a method to accomplish Boolean operation based on the distance filed of two meshes is proposed. The interference elimination can be conducted on the basis of marching cubes algorithm and Boolean operation. The accuracy of the dental splint can be guaranteed since the original mesh is utilized to form the result surface. Using EasySplint, the dental splints can be designed in about 10 minutes and saved as a stereo lithography (STL) file for 3D printing in clinical applications. Three phantom experiments were conducted and the efficiency of our method was demonstrated. Copyright © 2017, The Authors. All rights reserved.

关键词： computer software