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Exploring Content Popularity in Information-Centric Networks

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China Communications 2015年第7期12卷 13-22页

作者： Andriana Ioannou stefan Weber School of Computer Science and statistics Trinity College

Information-Centric Networking(ICN), an alternative architecture to the current Internet infrastructure, focuses on the distribution and retrieval of content by employing caches in a network to reduce network traffic. The employment of caches may be accomplished using graph-based and content-based criteria such as the position of a node in a network and content popularity. The contribution of this paper lies on the characterization of content popularity for on-path in-network caching. To this end, four dynamic approaches for identifying content popularity are evaluated via simulations. Content popularity may be determined per chunk or per object, calculated by the number of requests for a content against the sum of requests or the maximum number of requests. Based on the results, chunk-based approaches provide 23% more accurate content popularity calculations than object-based approaches. In addition, approaches that are based on the comparison of a content against the maximum number of requests have been shown to be more accurate than the alternatives.

关键词： network distributed architectures future internet information-centric networks caching technologies on-path caching content popularity

Support elements in conventional tunneling–Focus on long-term behavior

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Underground Space 2018年第4期3卷 277-287页

作者： Robert Galler stefan Lorenz Chair of Subsurface Engineering Department of Mineral Resources EngineeringMontanuniversita¨t LeobenP.O.Box 8700Erzherzog Johann Str.3LeobenAustria

Owing to increasing traffic and the need for constructing second tunnel tubes including corresponding cross-passages,where only one tube existed thus far,sampling of tunnel-lining materials with an age of 30–40 years has been made *** and in situ tests were carried out to evaluate the long-term effects of the tunnel *** paper presents the outcomes regarding the long-term behav-ior of support elements and membranes after performing strength tests on inner and outer lining concrete samples,flat jack tests,rock bolt tests,and tests on re-extracted sheet membranes,as well as ***,the interface connection mechanical behavior in a double-shell-lined tunnel was investigated with laboratory *** aim of this research was to determine the characteristics of sheet membranes and geotextiles in the case of reduced load-bearing capacity caused by degradation of the primary *** results provide information on the load-sharing effects of the interaction between the primary and secondary lining,depending on the waterproofing sheet membrane and geotextile *** on the results,conclusions for new design approaches for underground infrastructure construction can be formulated.

关键词： Tunnel lining Long-term behavior Concrete Sheet membrane Rock bolt Flat jack test In situ tests

Carbon Footprint of Transitional Shelters

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International Journal of Disaster Risk Science 2015年第3期6卷 226-237页

作者： Matti Kuittinen stefan Winter Department of Architecture School of Arts Design and Architecture Aalto University Faculty of Civil Geo and Environmental EngineeringTechnische Universitt München

Extreme weather events, sea level rise, and political disputes linked to climate change are driving masses to leave their homes. Their transitional settlements should be produced in a manner that causes minimum greenhouse gas(GHG) emissions to prevent any further acceleration of climate change and the humanitarian crises it causes. This article presents a study of the carbon footprint and primary energy demand of the construction materials of eight different transitional shelters. The lowest carbon footprints were found from shelter models made from bamboo or timber. The highest emissions were caused by shelters that have either a short service life or that are made from metal-intensive structures. The choice of cladding materials was surprisingly important. The findings were further compared to the overall impacts of each construction project, to national per capita GHG emissions,and to construction costs. Some shelter projects had notable total energy consumption even compared to the annual energy use of industrialized countries. The study concludes that construction materials have an important impact on the carbon footprint of shelters. Comparisons should however be made only between similar functional units. Furthermore, benchmark values and more background data are urgently needed in order to give humanitarian nongovernmental organizations tools for lowering the carbon footprint of their construction operations.

关键词： Carbon footprint Humanitarian construction Lifecycle assessment Primary energy

IMPROVING SOLVER PERFORMANCE THROUGH REDUNDANCY

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Journal of Systems Science and Systems Engineering 2016年第3期25卷 303-325页

作者： Eduardo Lalla-Ruiz stefan Voβ Department of Computer Engineering and Systems University of La Laguna Spain Institute of Information Systems (IWI) University of Hamburg Germany Eseuela de Ingenierla Industrial Pontificia Universidad Catolica de Valparaiso (PUCV) Chile

It is well known that hierarchies of mathematical programming formulatlons with different numbers of variables and constraints have a considerable impact regarding the quality of solutions obtained once these formulations are fed to a commercial solver. In addition, even if dimensions are kept the same, changes in formulations may largely influence solvability and quality of results. This becomes evident especially if redundant constraints are used. We propose a related framework for information collection based on these constraints. We exemplify by means of a well-known combinatorial optimization problem from the knapsack problem family, i.e., the multidimensional multiple-choice knapsack problem （MMKP）. This incorporates a relationship of the MMKP to some generalized set partitioning problems. Moreover, we investigate an application in maritime shipping and logistics by means of the dynamic berth allocation problem （DBAP）, where optimal solutions are reached from the root node within the solver.

关键词： Erraticism redundant constraints multidimensional multiple-choice knapsack problem,dynamic berth allocation problem

A review on the aging phenomena of organic components and their mass transfer through the NAPL interfacial phase

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Chinese Journal Of Geochemistry 2013年第3期32卷 252-260页

作者： LIU Lihua stefan Haderlein Key Laboratory of Renewable Energy and Gas Hydrate Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Eberhard-Karls-University of Tuebingen Center for Applied Geoscience (ZAG)

It occurs worldwide that the organic components of non-aqueous phase liquid (NAPL) enter the porous medium and become the source of contaminants in the subsurface. The transport of the organic components through NAPL interphase into the aqueous phase and the subsurface determines the extent of contamination, the persistence of residual NAPL phases and the techniques of remediation. During the transport process the NAPL interphase may experience "aging", a physical and chemical change when NAPL is exposed to aqueous and or gaseous phases. This aging process alters vice versa the mass transfer behaviour of the organic contaminants in the porous medium.

关键词：老化现象有机组成传质界面相部分和非水相液体评论污染物源

Risk-Layering for Indirect Effects

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International Journal of Disaster Risk Science 2021年第5期12卷 770-778页

作者： stefan Hochrainer-stigler Karina Reiter IIASA-International Institute for Applied Systems Analysis A-2361 Laxenburg.Austria

Environmental risks are one of the greatest threats in the twenty-first *** in the last years,the cascading impacts and risks associated with such events have received great attention as economic losses and consequences have mounted in their *** concerns about these ripple effects are rising,strategies to prevent and manage indirect risks are in urgent ***,such effects are currently barely considered in most countries and can seriously threaten global agendas such as achieving the Sustainable Development Goals by 2030 or the targets set out in the Sendai Framework for Disaster Risk Reduction *** discuss how the concept of risk-layering,which,though already applied in disaster risk management,could be expanded to include indirect *** point out some of the benefits,limitations,and ways forward for using this *** do so,we first delineate the transition of the risk-layering concept,which originated from the insurance industry,from its original use to its application in a wider *** bring special focus to the application of risk-layering in disaster risk management and identify strategies that allow for the inclusion of indirect *** main suggestion is that,while a probabilistic approach is appropriate for evaluating direct risks,a focus on connectedness is appropriate for indirect risks,which still allows for an easy link to direct ***,so we argue,facilitates more comprehensive risk management systems apt to deal with the multi-dimensional challenges ahead.

关键词： Connectedness Indirect risks Natural hazards and disasters Risk-layering Risk management

Analysis of the Caratheodory's Theorem on Dynamical System Trajectories Under Numerical Uncertainty

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IEEE/CAA Journal of Automatica Sinica 2018年第4期5卷 787-793页

作者： Pavel Osinenko Grigory Devadze stefan streif Automatic Control and System Dynamics Laboratory Technische Universitat Chemnitz09107 ChemnitzGermany IEEE

The current work proposes a new and constructive proof for the Caratheodory's theorem on existence and uniqueness of trajectories of dynamical systems. The key concern is the numerical uncertainty, i.e., the discrepancy between mathematical proofs, algorithms, and their implementations, which may affect the correct functioning of a control system. Due to growing demands on security and compliance with specifications,correctness of the control system functioning is becoming ever more important. Since in both dynamical systems and many control design approaches, one of the central notions is the system trajectory, it is important to address existence and uniqueness of system trajectories in a way which incorporates numerical uncertainty. Constructive analysis is a particular approach to formalizing numerical uncertainty and is used as the basis of the current work. The major difficulties of guaranteeing existence and uniqueness of system trajectories arise in the case of systems and controllers which possess discontinuities in time,since classical solutions to initial value problems do not *** issue is addressed in Caratheodory's theorem. A particular constructive variant of the theorem is proven which covers a large class of problems found in practice.

关键词： Constructive analysis Caratheodory’s theorem dynamical systems

Pathological tumor response to neoadjuvant therapy in borderline resectable pancreatic cancer

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Hepatobiliary & Pancreatic Diseases International 2019年第4期18卷 305-306页

作者： stefan Heinrich General Visceral and Transplantation Surgery University Hospital of Mainz

Surgery is the standard therapy for pancreatic ductal adenocarcinoma(PDAC).After the dramatic decline of operative mortality over the past decades,the indications for pancreas resections have been continuously extended:currently resections of the portal/superior mesenteric vein are considered standard by many centers,and even arterial resections are under *** these changes,different expert groups have defined resectability criteria containing a grey zone(“borderline resectable disease”)of tumors,which may be technically resectable with appropriate surgical expertise,but resection inherits an increased risk of an R1-resection[1].

关键词： Surgery mortality operative

Biomimetic Precipitation of Uniaxially Grown Calcium Phosphate Crystals from Full-Length Human Amelogenin Sols

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Journal of Bionic Engineering 2011年第2期8卷 114-121页

作者： Vuk Uskokovie Wu Li stefan Habelitz Division of Biomaterials and Bioengineering Department of Preventive and Restorative Dental Sciences University of Calil'ornia 707 Parnassus Avenue San Francisco CA 94143 USA Department of Orofacial Sciences University of California 513 Parnassus Avenue San Francisco CA 94143 USA

Human dental enamel forms over a period of 2 4 years by substituting the enamel matrix, a protein gel mostly composed of a single protein, amelogenin with fibrous apatite nanocrystals. Self-assembly of a dense amelogenin matrix is presumed to direct the growth of apatite fibers and their organization into bundles that eventually comprise the mature enamel, the hardest tissue in the mammalian body. This work aims to establish the physicochemical and biochemical conditions for the synthesis of fibrous apatite crystals under the control of a recombinant full-length human amelogenin rnatrix in combination with a pro- grammable titration system. The growth of apatite substrates was initiated from supersaturated calcium phosphate solutions in the presence of dispersed amelogenin assemblies. It was shown earlier and confirmed in this study that binding of amelogenin onto apatite surfaces presents the first step that leads to substrate-specific crystal growth. In this work, we report enhanced nucleation and growth under conditions at which amelogenin and apatite carry opposite charges and adsorption of the protein onto the apatite seeds is even more favored. Experiments at pH below the isoelectric point of amelogenin showed increased protein binding to apatite and at low Ca/P molar ratios resulted in a change in crystal morphology from plate-like to fibrous and rod-shaped. Concentrations of calcium and phosphate ions in the supernatant did not show drastic decreases throughout the titration period, indicating controlled precipitation from the protein suspension metastable with respect to calcium phosphate. It is argued that amelobtasts in the developing enamel may vary the density of the protein matrix at the nano scale by varying local pH, and thus control the interaction between the mineral and protein phases. The biomimetic experimental setting applied in this study has thus proven as convenient for gaining insight into the fundamental nature of the process ofamelogenesi

关键词： enamel amelogenin biomineralization apatite biomimetics