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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Der Ophthalmologe 95 (1998), S. 176-180 
    ISSN: 1433-0423
    Keywords: Key words Cyclophotocoagulation • Diode laser • Ultrasound biomicroscopy ; Schlüsselwörter Zyklophotokoagulation • Diodenlaser • Ultraschallbiomikroskop
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um die therapeutische Effektivität der Glaukomtherapie mittels Diodenlaserzyklophotokoagulation zu evaluieren, wurden die intraokularen Tensionswerte (IOP) nach Zyklophotokoagulation an 106 Augen 8–24 Monate postoperativ erfaßt. Methode: 24–30 Laserherde mit einer Energie von 2,8–3,6 J wurden mittels Fokussieroptik 1,5 mm hinter dem Limbus zirkulär über 360 ° gesetzt. 25 der operierten Augen wurden postoperativ ultraschallbiomikroskopisch auf Ziliarkörperveränderungen untersucht. Ergebnisse: Der mittlere IOP sank von präoperativ 25,0 ± 5,7 mm Hg auf 18,0 ± 6,0 mm Hg langfristig postoperativ. Eine erfolgreiche Tensionsregelung (IOP 〈 22 mm Hg bzw. dauerhafte Schmerzfreiheit bei funktionslosen Augen) wurde bei 85 % der Augen erreicht, wobei bei 23 Augen mehr als 1 Zyklophotokoagulation durchgeführt werden mußte und 6 Augen wegen der Notwendigkeit einer anderen tensionsregulierenden Operation aus der Studie ausschieden. Es traten keine schwerwiegenden Komplikationen auf. Die morphologischen Untersuchungen zeigten bei 22 von 25 Augen eine temporäre postoperative Ziliarkörperschwellung und bei 8 Augen eine temporäre Ziliarkörperabhebung. Schlußfolgerung: Die Zyklophotokoagulation mit dem Diodenlaser führt bei verschiedenen Glaukomarten risikoarm auch langfristig zu einer effektiven IOP-Senkung. Morphologisch zeigt sich postoperativ eine entzündliche Reaktion im Ziliarkörper, deren Ausmaß nicht mit der Höhe der Tensionssenkung korreliert.
    Notes: Summary To assess the clinical effectiveness of glaucoma therapy with diode laser cyclophotocoagulation, 106 eyes (51 eyes with primary open-angle glaucoma, 22 eyes with secondary glaucoma, 10 eyes with narrow-angle glaucoma, 23 eyes with other glaucomas) of 87 patients were treated. Using a diode laser coupled with a fiberoptic probe, ending in a focusing tip, all eyes were treated with 24–30 spots over 360 ° and 2.8–3.6 J of energy, 1.5 mm posterior to the limbus. The intraocular pressure was obtained over a period of time until 8–24 months after operation. Additionally, morphological changes of the ciliary body were observed in 25 eyes by means of ultrasound biomicroscopy. Results: The IOP decreased from a baseline mean of 25.0 ± 5.7 mm Hg to 17.6 ± 5.3 mm Hg directly after operation and increased sligthly to 18.0 ± 6.0 mm Hg in the following 24 months. Successful control of IOP (IOP constantly 〈 22 mm Hg or pain relief in blind eyes) occurred in 90 of 106 eyes (84.9 %). In 23 eyes more than one treatment was given. In 6 eyes another IOP-reducing operation had to be performed. In 19 eyes slightly elongated intraocular inflammatory reactions were seen, without any serious complications. The morphological investigations showed in 22 of 25 cases temporary edema of the ciliary body. A temporary detachment of the ciliary body was seen in 8 eyes. Conclusions: Diode laser cyclophotocoagulation is an effective and safe procedure to reduce IOP in different types of glaucoma over a long time. Postoperatively, a temporary inflammatory reaction of the ciliary body was observed with no correlation to the degree of reduction of the IOP.
    Type of Medium: Electronic Resource
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  • 2
    Publication Date: 2020-08-05
    Description: Wieviele Punkte braucht eine Mannschaft in der Fußball-Bundesliga mindestens, um sicher dem Abstieg zu entgehen? Wir benutzen kombinatorische Optimierung, um diese und ähnliche Fragen zu beantworten.
    Language: German
    Type: reportzib , doc-type:preprint
    Format: application/pdf
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  • 3
    Publication Date: 2020-11-16
    Description: Das vom BMBF geförderte Projekt FTTX-PLAN entwickelt mathematische Modelle und Optimierungsverfahren, um automatisiert kostenoptimierte FTTx-Netze berechnen zu können. Wir zeigen anhand einer Praxisstudie in Zusammenarbeit mit der Regensburger R-KOM, wie ein Planer von diesen Verfahren profitieren kann, um die Auswirkungen bestimmter Entscheidungen auf die Netzstruktur und -kosten zu untersuchen. Wir illustrieren dies am Beispiel eines FTTB/FTTH-Vergleichs, der Variation von Kundenanbindungsraten und der gezielten Ausnutzung existierender Leerrohre, um Tiefbau zu vermeiden.
    Language: German
    Type: reportzib , doc-type:preprint
    Format: application/pdf
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  • 4
    Publication Date: 2020-08-05
    Description: In this paper we assess to which extent trenching costs of an FTTx network are unavoidable, even if technical side constraints are neglected. For that purpose we present an extended Steiner tree model. Using a variety of realistic problem instances we demonstrate that the total trenching cost can only be reduced by about 5 percent in realistic scenarios. This work has been funded by BMBF (German Federal Ministry of Education and Research) within the program "KMU-innovativ".
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
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  • 5
    Publication Date: 2020-08-05
    Description: Energy-efficient operation of large telecommunication networks is an important issue today and in the near future. Given that the energy consumption rises with the ever increasing demand for capacity and network speed, there is a growing interest in strategies for a sustainable network management. It is a well-known fact that traffic demands vary significantly over time, most notably in day/night- and in weekly cycles. This provides the main potential for energy-saving strategies. We study the question of how much power is necessary to operate a network with state-of-the-art hardware during peak or low-traffic times. The study respects realistic side constraints, such as protection requirements and routing schemes, and takes the special structure of an extensive nation-wide optical network, including backbone and regional sections, into account. We formulate mixed integer programming models for the corresponding optimization problems using predictions for traffic matrices, as well as state-of-the-art hardware and power models. We address questions as the following: How much energy is spent in the core and in metro regions of the network and how big are the savings in low-demand scenarios if we always assume the system power-minimum in these situations? What is the influence of different hardware on the overall energy consumption? How much do different routing schemes or protection scenarios restrict potential energy savings?
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/pdf
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  • 6
    Publication Date: 2020-08-05
    Description: Sports rankings are obtained by applying a system of rules to evaluate the performance of the participants in a competition. We consider rankings that result from assigning an ordinal rank to each competitor according to their performance. We develop an integer programming model for rankings that allows us to calculate the number of points needed to guarantee a team the ith position, as well as the minimum number of points that could yield the ith place. The model is very general and can thus be applied to many types of sports. We discuss examples coming from football (soccer), ice hockey, and Formula~1. We answer various questions and debunk a few myths along the way. Are 40 points enough to avoid relegation in the Bundesliga? Do 95 points guarantee the participation of a team in the NHL playoffs? Moreover, in the season restructuration currently under consideration in the NHL, will it be easier or harder to access the playoffs? Is it possible to win the Formula~1 World Championship without winning at least one race or without even climbing once on the podium? Finally, we observe that the optimal solutions of the aforementioned model are associated to extreme situations which are unlikely to happen. Thus, to get closer to realistic scenarios, we enhance the model by adding some constraints inferred from the results of the previous years.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
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  • 7
    Publication Date: 2020-08-05
    Description: In this paper we study the cost-optimal deployment of optical access networks considering variants of the problem such as fiber to the home (FTTH), fiber to the building (FTTB), fiber to the curb (FTTC), or fiber to the neighborhood (FTTN). We identify the combinatorial structures of the most important sub-problems arising in this area and model these, e.g., as capacitated facility location, concentrator location, or Steiner tree problems. We discuss modeling alternatives as well. We finally construct a “unified” integer programming model that combines all sub-models and provides a global view of all these FTTx problems. We also summarize computational studies of various special cases.
    Language: English
    Type: reportzib , doc-type:preprint
    Format: application/pdf
    Format: application/pdf
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  • 8
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    Unknown
    Publication Date: 2020-08-05
    Language: English
    Type: other , doc-type:Other
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  • 9
    Publication Date: 2020-08-05
    Language: English
    Type: article , doc-type:article
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  • 10
    Publication Date: 2020-08-05
    Language: English
    Type: conferenceobject , doc-type:conferenceObject
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