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Found 6289 publications

Safety Assessment of Different Stability Design Rules for Beam-columns

G. Hajdú Ferenc Papp

Publication Name: Structures

Publication Date: 2018-06-01

Volume: 14

Issue: Unknown

Page Range: 376-388

Description:

In EC3-EN 1993-1-1, there are three different methods to check the global stability resistance of steel columns, beams, and beam-columns. The design formulas are based on buckling curves, which are available for purely compressed or purely bended members with uniform cross-sections. Beam-columns are subjected to compressive force and the bending moment can be designed using the so-called interaction formula where the interaction factors may be alternatively determined. Over the past few years, many research groups have worked on correcting and improving the accuracy of the available design methods for steel members. The aim of this paper is to compare the accuracy of the different revised methods for steel beam-columns. In order to investigate the accuracy of the above-mentioned design methods, numerous geometrically and materially nonlinear analyses with imperfections (also known as GMNIA) were executed by previous research projects. The results of the semi-probabilistic safety assessments may help the designer choose the most reasonable method for their design works.

Open Access: Yes

DOI: 10.1016/j.istruc.2018.05.002

Felix somló's three theories of state

Péter Takács

Publication Name: Hungarian Journal of Legal Studies

Publication Date: 2018-06-01

Volume: 59

Issue: 2

Page Range: 216-227

Description:

This paper examines the excellent Hungarian legal philosopher, Felix Somló's theories on the state and politics. It claims that Somló had three theories of state. The first could be reconstructed from the sociological allusions and hints of his first book, titled Állami beavatkozás és individualismus [State intervention and individualism] (1903). His second theory of state was based on legal concepts exposes in a Neo-Kantian fashion, and it has been explicated in his Juristische Grundlehre [Basic Legal Concepts and Ideas] (1917). His third theory of state is an unfinished theory prepared in his unpublished Állambölcseleti jegyzetek [Notes for a Philosophy of State] (1919/20). The core idea of the first theory is regulation (which was considered by Somló as interference); the central concept of the second theory is the so called 'Rechtsmacht' [legal might], which was coined by Somló; whereas the third theory revolves around the possibility of so called eternal truth of history of ideas.

Open Access: Yes

DOI: 10.1556/2052.2018.59.2.6

Methodology for DNS cache poisoning vulnerability analysis of DNS64 implementations

Gábor Lencse Y. Kadobayashi

Publication Name: Infocommunications Journal

Publication Date: 2018-06-01

Volume: 10

Issue: 2

Page Range: 13-25

Description:

The trustworthy operation of the DNS service is a very important precondition for a secure Internet. As we point it out, DNS cache poisoning could be even more dangerous if it is performed against DNS64 servers. Based on RFC 5452, we give an introduction to the three main components of DNS cache poisoning vulnerability, namely Transaction ID prediction, source port number prediction, and a birthday paradox based attack, which is possible if a DNS or DNS64 server sends out multiple equivalent queries (with identical QNAME, QTYPE, and QCLASS fields) concurrently. We design and implement a methodology and a testbed, which can be used for the systematic testing of DNS or DNS64 implementations, whether they are susceptible to these three vulnerabilities. We perform the tests with the following DNS64 implementations: BIND, PowerDNS, Unbound, TOTD (two versions) and mtd64-ng. As for the testbed, we use three virtual Linux machines executed by a Windows 7 host. As for tools, we use VMware Workstation 12 Player for virtualization, Wireshark and tshark for monitoring, dns64perf for Transaction ID and source port predictability tests, and our currently developed “birthday-test” program for concurrently sent multiple equivalent queries testing. Our methodology can be used for DNS cache poisoning vulnerability analysis of further DNS or DNS64 implementations. A testbed with the same structure may be used for security vulnerability analysis of DNS or DNS64 servers and also NAT64 gateways concerning further threats.

Open Access: Yes

DOI: DOI not available

A review of elasto-plastic shakedown analysis with limited plastic deformations and displacements

Majid Movahedi Rad

Publication Name: Periodica Polytechnica Civil Engineering

Publication Date: 2018-05-22

Volume: 62

Issue: 3

Page Range: Unknown

Description:

In classical plasticity the shakedown analysis is among the most important basic problems. The principles of shakedown analysis are counterparts to those of limit analysis in the sense that they provide static and kinematic approaches to the question of whether or not shakedown will occur for a body under multiple variable loading conditions. The principles of limit analysis provide static and kinematic approaches to the question of whether or not the plastic limit state will be reached by a body under proportional loading. The principles of shakedown analysis are, however, considerably more difficult to apply than those of limit analysis. In spite of these difficulties, shakedown analysis is a vital and developing topic in plasticity and a great number of applications have been made. At the application of the plastic analysis and design methods the control of the plastic behaviour of the structures is an important requirement. Since the shakedown analysis provide no information about the magnitude of the plastic deformations and residual displacements accumulated before the adaptation of the structure, therefore for their determination bounding theorems and approximate methods have been proposed.

Open Access: Yes

DOI: 10.3311/PPci.11696

Verification of the Ramberg-Osgood material model in midas GTS NX with the modeling of torsional simple shear tests

Zsolt Szilvágyi Richard P. Ray

Publication Name: Periodica Polytechnica Civil Engineering

Publication Date: 2018-05-22

Volume: 62

Issue: 3

Page Range: Unknown

Description:

This study focuses on the back analysis of a geotechnical laboratory test with nonlinear finite element modeling using the Ramberg-Osgood material model. This model has been used by several authors recently for nonlinear ground response analysis and it has been implemented by Midas into their commercial finite element code Midas GTS NX 2014. The verification of the model for 1D nonlinear site response analysis can be found in the documentation of the software package. In this study, Torsional Simple Shear tests were modeled and a comprehensive study was performed to provide verification of the material model for static torsional loading and axisymmetric conditions.

Open Access: Yes

DOI: 10.3311/PPci.11191

Domestication and proliferation of algae cultures for boosting efficiency of waste-water treatment through symbiosis

László Tolner András J. Kovács Imre Tolner Zsolt Méhes

Publication Name: Periodica Polytechnica Chemical Engineering

Publication Date: 2018-05-16

Volume: 62

Issue: 3

Page Range: 292-298

Description:

Native algae strains have been domesticated and stimulated in activated sludge wastewater treatment operations. The term of domestication indicates that we did not add any selected algae to the wastewater, but made use of species existing in the system. The term of proliferation indicates a stimulation of the biological oxidation process by provision of CO2 with the air stream and illumination of the reactor. The idea of domestication of algae present in communal wastewater systems was demonstrated. Stimulation of the system with domesticated algae community did improve efficiency of the treatment process. Removal of organic components in terms of reduction of chemical and biological oxidation demands (dissolved COD, BOD) as well as nitrogen and phosphorous contents was superior to extent of removal in conventional activated sludge system. We did conclude that conventional systems lack available light and carbon resources for these microorganisms. Upon providing these, symbiotic operation can contribute to reducing greenhouse gas emissions and increase of the rate of pollutants removal kinetics. Symbiotic operation increased the production of biomass expressed in terms of total suspended solids. Biodiesel potential of the filterable biomass was in the range of 8-18%. Because of technical difficulties in manipulation of the excess sludge other than biodiesel synthesis processing scheme has been recommended for economically viable processing.

Open Access: Yes

DOI: 10.3311/PPch.11096

Measurement and analysis of delivery van vibration levels to simulate package testing for parcel delivery in Hungary

Péter Böröcz S. Paul Singh

Publication Name: Packaging Technology and Science

Publication Date: 2018-05-01

Volume: 31

Issue: 5

Page Range: 342-352

Description:

In the past several decades, there continues to be an increase in both domestic and international online and catalogue shipments that requires an increase in shipments and handling of parcels by single parcel delivery companies. This study measured the vibration levels that occur in parcel delivery shipments from pickup to delivery, especially the sections involving delivery vans and small vehicles over ground road transportation in Hungary. Goods that were shipped in the regions studied almost always travel at least once by van on varying road conditions such as motorways, main, side or city roads to deliver parcels to the final destination. The aim of this paper was to provide an understanding of vibration levels that occur during van transportation that can be used to pre-shipment test new packages to prevent damage. The measured acceleration-time data were analyzed in terms of power spectral densities (PSDs) and presented with statistical data to provide an understanding of the variability of intensity. The separated and averaged vibration levels that were measured in this study were compared with the American Society of Testing and Materials and the International Safe Transit Association vibration profiles for pickup and delivery vehicle in the form of PSD spectrums. Based on the analyzed data of this study, PSD spectra were provided for various route conditions as well as composite spectra, which can be used to simulate the measured vibration conditions representing van shipments.

Open Access: Yes

DOI: 10.1002/pts.2327

Calcium oscillations in fertilized pig oocytes are associated with repetitive interactions between STIM1 and ORAI1

Chi Hong Chao Lu Zhang Zoltan Machaty Ágnes Bali Papp Laurie A. Jaeger

Publication Name: Biology of Reproduction

Publication Date: 2018-04-01

Volume: 98

Issue: 4

Page Range: 510-519

Description:

The Ca 2+ entry mechanism that sustains the Ca 2+ oscillations in fertilized pig oocytes was investigated. Stromal interaction molecule 1 (STIM1) and ORAI1 proteins tagged with various fluorophores were expressed in the oocytes. In some cells, the Ca 2+ stores were depleted using cyclopiazonic acid (CPA); others were inseminated. Changes in the oocytes' cytosolic free Ca 2+ concentration were monitored, while interaction between the expressed fusion proteins was investigated using fluorescence resonance energy transfer (FRET). Store depletion led to an increase of the FRET signal in oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, indicating that Ca 2+ release was followed by an interaction between these proteins. A similar FRET increase in response to CPA was also detected in oocytes co-expressing mVenus-STIM1 and mTurquoise2-STIM1, which is consistent with STIM1 forming punctae after store depletion. ML-9, an inhibitor that can interfere with STIM1 puncta formation, blocked store-operated Ca 2+ entry (SOCE) induced by Ca 2+ add-back after a CPA treatment; it also disrupted the Ca 2+ oscillations in fertilized oocytes. In addition, oocytes overexpressing mVenus-STIM1 showed high-frequency Ca 2+ oscillations when fertilized, arguing for an active role of the protein. High-frequency Ca 2+ oscillations were also detected in fertilized oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, and both of these high-frequency Ca 2+ oscillations could be stopped by inhibitors of SOCE. Importantly, in oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, we were also able to detect cyclic increases of the FRET signal indicating repetitive interactions between STIM1 and ORAI1. The results confirm the notion that in pig oocytes, SOCE is involved in the maintenance of the repetitive Ca 2+ transients at fertilization.

Open Access: Yes

DOI: 10.1093/biolre/ioy016

Nguyen type theorem for extension principle based on a joint possibility distribution

Lucian Coroianu Robert Fuller

Publication Name: International Journal of Approximate Reasoning

Publication Date: 2018-04-01

Volume: 95

Issue: Unknown

Page Range: 22-35

Description:

In this paper, first we prove that making abstraction of the output obtained from the interactive extension principle based on a joint possibility distribution, in the case of unimodal fuzzy numbers and when the function that generates the operation is continuous and strictly increasing in each argument restricted to the support of each fuzzy number used in the process, then we can use joint possibility distributions with the property that the left/right side of the output is obtained from the convolution of the values in the left/right side of these fuzzy numbers. Then, considering joint possibility distributions with the aforementioned property, we find an Nguyen type characterization of the level sets of the output based on interactive extension principle, in terms of the level sets of the fuzzy numbers used in the process. These two key results complete well-known results obtained in the case of Zadeh's extension principle and also in the case of triangular norm-based extension principle. As an interesting corollary, in the special case of unimodal fuzzy numbers, the Nguyen theorem can be used to present a new proof concerning necessary and sufficient conditions on the equality of the outputs based on joint possibility distributions, respectively based on Zadeh's extension principle.

Open Access: Yes

DOI: 10.1016/j.ijar.2018.01.007