Combining IntServ and DiffServ under Linux

Combining Integrated Services ([1], [5]) QoS mechanisms for end-to-end signaling at hosts and Differentiated Services ([2], [10]) QoS mechanisms in the network core is one proposal for overcoming the limitation of either mechanisms when applied alone ([8]). In this paper some of the open issues in [8] are discussed and a concrete proposal is presented, which maps the IntServ Controlled Load Service into the DiffServ Expedited Forwarding Per Hop Behavior. The proposed approach has been implemented under the Linux Operating System. The implementation allows verifying the correct functional behavior and provides a platform where more complete performance tests are possible

Nondestructive testing - NDT: Amphitheater in Pula

Zahvaljujući nerazornim metodama ispitivanja, NDT, moguće je ispitivati objekte od povijesnog značaja i time stvarati jasniju predodžbu o stvarnom stanju njihove konstrukcije. Sva ispitivanja je potrebno provesti uz što manje oštećivanja postojeće strukture te je stoga potrebno vrlo pažljivo odrediti vrstu i obim zahvata. U provedbi ispitivanja koriste se dinamičke probe, statičke probe, tehnička dijagnoza pomoću rezultata ispitivanja NDT metodama i NDT monitoringa konstrukcije. Pomoću nerazornih metoda kontrole mogu se utvrditi na samom objektu svi potrebni parametri za pouzdanije i sigurnije projektiranje sanacije. NDT monitoring koji omogućuje kontinuirano praćenje ponašanja konstrukcij može započeti prije sanacije, trajati tijekom i nakon izvedene sanacije u provedbi kontrole izvedenih radova. Dinamičke karakteristike konstrukcije daju realno stanje objekta u fazi eksploatacije. One se određuju eksperimentalno bilježenjem funkcije reagiranja konstrukcije na određenu pobudu kao što je u konkretnom slučaju cestovni promet, zračni promet, utjecaj vjetra i glazbene manifestacije. U svrhu riješevanja ove problematike potrebno je izvršiti snimanje utjecaja vibracija navedenih pobuda. U ispitivanju konstrukcije Arene nerazornim metodama najčešće se primjenjuje magnetska metoda, ultrazvučna metoda ispitivanja, georadar, itd., NDT monitoring konstrukcije, snimanje morfologije nosećih zidova i temelja, te mjerenje napona u zidanoj konstrukciji. Temeljem rezultata ispitivanja dobivaju se potrebne informacije na temelju kojih će se izraditi projekt sanacije konstrukcije Arene. To je vrlo složen problem u čijem rješavanju sudjeluju stručnjaci raznih profila, arheolozi, restauratori, povjesničari umjetnosti te arhitekti i građevinari-statičari koji nastupaju često sa suprotnih početnih pozicija, ali uz rezultate NDT ispitivanja ostvaruju postavljeni cilj, a to je sigurnost građevine.Thanks to non-destructive testing (NDT), it is possible to test the objects of historic significance and thus build up a clearer picture of their current condition. For the purposes of recovery these data are invaluable. Dynamic examination, static examination, technical diagnosis based on the NDT results and NDT monitoring of the structure of an object can determine all necessary parameters on the object, which is crucial for more reliable and safer design of the recovery. NDT monitoring enables continuous supervision of the structure; it can start before the recovery, take place during and after the recovery and has been carried out within the framework of controlling of the performed work. Dynamic characteristics of the structure provide the information on the real condition of an object in the phase of exploitation. They can be experimentally measured by recording the response of the structure to the specific excitation, such as, in this case, road traffic, air traffic, influences of wind and music festivals. With the aim to tackle these issues, it is necessary to undertake the activities in recording of the influence of vibrations caused by named excitation of the load-bearing walls morphology and of the foundation morphology using NDT methods (it is common to use MT, UT, georadar etc.). Information provided, based on the results of testing, are necessary for this very complex problem. Many experts involved, such as archeologists, restoration teams, art historians, architects and construction workers had starting perspective often different, but with joint activities and NDT results they reach the same goal and that is the safety of the structure and preservation of a centuries-old building

Scalable resource reservation for the Internet

For some time now, the design of architectures for providing dependable Quality of Service (QoS) on multimedia networks has been a busy topic in academia and industry. In this work we look at practical aspects of Quality of Service, and in particular at resource reservation for the Internet. Initially, our focus was on ATM, which looked like the most promising QoS technology at the time. We proposed, implemented, and demonstrated Arequipa, a mechanism that uses ATM to provide QoS for TCP/IP, and which only requires end-to-end connectivity, but no changes in the ATM network. While ATM still has its place, the Differentiated Services architecture, which returns to the paradigm of packet-oriented processing in the network, is nowadays a more likely candidate for providing a basis for supporting dependable Quality of Service in the Internet. We therefore concentrated on Differentiated Services when looking for solutions to overcome some of the problems we found in the reservation models in Arequipa and the underlying ATM. Our work culminates in the development of SRP, the "Scalable resource Reservation Protocol", a highly scalable yet conceptually simple reservation protocol for TCP/IP. SRP achieves scalability by aggregating flows in the network, and by controlling flow admission by making simple per-packet decisions, which are based on estimates of the bandwidth available for reservation. We give a detailed description of the SRP architecture, including examples of estimation algorithms and an introduction to a novel approach for scalable policing. We describe how we integrated SRP in the ns simulator, and show simulation results. Finally, we have implemented SRP on top of Differentiated Services on Linux, and again we describe the implementation and give measurement results. We also discuss some of the infrastructure-building activities that have resulted from our work, namely the ATM on Linux project, documentation of Linux traffic control, and the Diffserv on Linux project

Komponenten der sportlichen Leistung im Ultimate Frisbee

Im Rahmen dieser Arbeit wurde die Teamsportart Ultimate Frisbee unter trainingswissenschaftlichen Aspekten betrachtet. Aufgrund des mäßigen Bekanntheitsgrades wurde in der Einleitung zunächst die Sportart Ultimate als Wettkampfsport vorgestellt um anschließend leistungsrelevante Faktoren, in Anlehnung an vergleichbare Teamsportarten, zu erörtern. Im empirischen Teil wurden 6 sportmotorische Tests entwickelt, wobei insgesamt 8 Test-Items rein koordinative und 4 weitere Items sowohl koordinative als auch konditionelle Fähigkeiten der Spieler/innen überprüfen sollten. Anhand dieser Testbatterie wurde ein Gesamtkollektiv von 67 Proband(inn)en getestet, die sich aus 34 Vereinsspieler/innen und einer Vergleichsgruppe von 33 Usi-Spieler/innen zusammensetzten. Das Untersuchungsinteresse stützte sich dabei auf 3 Kernfragen: Einfluss des Trainingsstatus auf das Leistungsniveau, Zusammenhang von Trainingsalter und Leistung, Einfluss des Geschlechts auf das Leistungsniveau. Die statistische Auswertung der Untersuchung brachte folgende Ergebnisse: Die Leistungsunterschiede zwischen Vereins- und Usi-Spieler(inne)n waren bei 7 Items signifikant. Zwischen Frauen mit unterschiedlichem Trainingsstatus fanden sich bei 4 Items, zwischen Vereins- und Usi-Spielern bei 5 von 8 Items mit rein koordinativen Anforderungen signifikante Unterschiede. Dabei erzielten stets die levelhöheren Spieler/innen bessere Ergebnisse. Hinsichtlich der 3 Items eines gemischt koordinativ-konditionellen Tests konnten zwischen allen eben genannten Teilgruppen keine signifikanten Unterschiede festgestellt werden. Die Ergebnisse bezüglich des Zusammenhangs von Trainingsalter und Leistungsniveau fielen ähnlich aus. Es konnten bei 10 von insgesamt 12 Items signifikante Korrelationen festgestellt werden. Bezüglich der Frage nach Leistungsunterschieden zwischen Spielerinnen und Spielern konnten bei 6 von 8 Test-Items mit ausschließlich koordinativen Anforderungen keine signifikanten Unterschiede festgestellt werden. Die Mittelwertsvergleiche der koordinativ-konditionellen Test-Items zeigten jedoch bei allen 4 Items signifikante Leistungsunterschiede zugunsten der Männer

Reservation Models, From Arequipa to SRP

We analyse and illustrate two approaches that we have developed for providing reservations to flows. The first approach uses the explicit reservation model: a traffic profile is negotiated between users and the network. ATM and RSVP are two examples for this approach. In this paper we describe our experience in the ACT project EXPERT (AC094) with the explicit reservation model in the context of ATM. We show that the integration of ATM in a TCP/IP oriented operating system is easy and does not require developing applications specially for ATM. The method we have designed is called Arequipa and is described in RFC 2170. It is fully implemented in Linux. However, we are confronted with the complexity required to support a single reservation for each flow. Our analysis is that it is well suited for segregating flows in applications such as private virtual networks, but that, for multimedia networks, the cost of handling a large number of flows is too high. This and other factors led us to develop an alternative solution, based on an implicit reservation model. Our solution is called the Scalable Reservation Protocol (SRP). SRP aggregates flows inside the network: routers other than edge routers performing policing do maintain only aggregate information per port. SRP is being developed and implemented in the framework of the ACTS project DIANA (AC319). Keywords: QoS; Aggregation; Arequipa; ATM; IP; SR

A Survey of Differentiated Services Proposals for the Internet

Abstract TR/1998/020 Technical Report SSC/1998/020 Authors: Constant Gbaguidi, Hans J. Einsiedler, Paul Hurley, Werner Almesberger and Jean-Pierre Hubaux Date: Title: A Survey of Differentiated Services Proposals for the Internet Abstract Differentiated services are a suitable solution to Quality of Service (QoS) provisioning in the Internet while the number of users keeps growing. The solution is suitable, because it scales well with increasing number of network users and it does not alter the current Internet paradigm much. In this article, we review the state of the art in this ÒnewÓ area, and compare some of the main existing differentiated services architectures. We outline the common solutions across these architectures, thus paving the road to a unified architecture. Lastly, we mention the issues that have not been thoroughly addressed yet

Updates and Debate Concerning Margin Adequacy and Management following Breast-Conserving Surgery

Objective: Breast-conserving surgery (BCS) experienced a significant surge during the last decades due to the increase of early breast cancer detection. Central to the discussion is margin adequacy which represents one of the most significant predictive factors for local relapse. This paper aims to shed light on the problem of margins in breast surgery. Mechanism: We performed a systematic narrative review of the literature by conducting a search using Medline/PubMed, Scopus, and Embase. The following keywords were considered: "breast-conserving surgery"AND "margins"/"margin". Findings in Brief: In the case of invasive breast cancer, "no ink on tumor"can be considered an adequate margin, while for ductal carcinoma in situ (DCIS), a distance of 2 mm from tumor should be obtained. Many novel tools have been developed based both on the latest radiological imaging techniques and on the tissue expression of certain markers, with the aim of precise navigation of tumor excision and intraoperative evaluation of cavity excision margins. Oncoplastic surgery can be considered oncologically safe while improving the cosmetic outcome and patients' quality of life. The appropriate use of adjuvant treatments in the context of a multidisciplinary and personalized management of breast cancer is the only means to omit a second intervention in some carefully selected cases. Conclusions: Debate still exists concerning the definition of adequate clear margin following BCS for DCIS. Further studies are required to better assess multimodal treatment approaches in this condition

Quality of Service Renegotiations

Giving users simple access to QoS selection capability of ATM networks is important for the future of integrated services networks. We describe the first instance of an application in which users had the capacity to tune ATM traffic parameters with a button, at run time. To achieve this we implemented the necessary signaling extension on ATM switches as well as on end-systems. Furthermore, we extended Arequipa (Application REQested IP over ATM; a mechanism that enables applications to request direct ATM connections for their exclusive use and to directly control their traffic parameters) to support modification, and modified the popular Mbone tool Vic (VIdeo Conferencing) to use Arequipa to request and modify ATM bandwidth at will. We describe how Vic accomplished this over the ATM WAN of SWISSCOM, transferring live video from Lausanne to Basel over switched, renegotiable ATM connections