Oliver Ullrich

Oliver Ullrich
Fraunhofer Institute for Intelligent Analysis and Information Systems IAIS | IAIS · Adaptive Reflective Teams (ART)

Dr. rer. nat.

About

55
Publications
12,467
Reads
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133
Citations
Introduction
Additional affiliations
November 2017 - present
March 2014 - August 2017
Florida International University
Position
  • Managing Director
October 2006 - February 2014
University of Cologne
Position
  • Research Associate

Publications

Publications (55)
Article
Full-text available
Risks related to climate change and natural hazards increasingly affect urban areas such as historic towns, old urban quarters, villages, and hamlets. These, as well as historic landscapes, make up a significant part of an urban area’s identity and cannot just be rebuilt or significantly changed without taking into account the historic value, cultu...
Article
Full-text available
Historic areas (HAs) are highly vulnerable to natural hazards, including earthquakes, that can cause severe damage, if not total destruction. This paper proposes methods that can be implemented through a geographical information system to assess earthquake-induced physical damages and the resulting impacts on the functions of HAs and to monitor the...
Conference Paper
Full-text available
The EU-H2020 project ARCH aims to develop and adapt tools and methods for assessing and improving the resilience of historic areas to climate-related and other natural hazards [1]. One of these tools is CIPCast, a scenario simulation and decision support system for the analysis and forecast of risks and vulnerabilities of critical infrastructure co...
Conference Paper
Full-text available
This paper applies the Tree-Attribute-Matrix (TAM) modelling method to a simplified model of an urban light-rail transportation system. The resulting model is a conceptual model that is beneficial for understanding, management and coordination of the system on a high level, in particular when different (interdisciplinary) stakeholders are involved....
Cover Page
Full-text available
Cover page, preface and table of contents. Proceedings available at https://www.asim-gi.org/fileadmin/user_upload_asim/ASIM_Publikationen_OA/AM174_OA/AM174_AR59_2020_vSST25_Proceedings_OA.pdf
Chapter
Full-text available
Consequences of climate change, like more frequent extreme weather events, are major challenges for urban areas. With diverse approaches for adaptation strategy development available to cities, comparability with respect to risks, vulnerabilities, and adaptation options is limited. The lack of standardized methods and approaches to prioritize and s...
Article
Full-text available
Some discrete simulation models are too large to be executed on a single processor; in other cases, results might be required faster than a sequential execution can provide them. Such models are candidates for parallelization. Here, models are distributed among several processors, and are then executed with careful synchronization.This paper provid...
Conference Paper
In bus transit networks without dedicated bus lanes vehicle traversal times are strongly dependent on the traffic density of the corresponding road segments. This paper takes the first steps towards demonstrating that the traffic density has regular patterns that yield a small number of periodic effects on the traversal time: the current traversal...
Chapter
This chapter gives an introduction to risk-based vulnerability assessment of urban infrastructure regarding the consequences of climate change, by describing an approach developed as part of the EU-funded research and innovation project Climate Resilient Cities and Infrastructures. The approach is modular, widely applicable, and supported by a suit...
Chapter
Extreme weather events resulting from climate change are severe threats to urban population centers with their high density of residents and economic assets. The combination of climate change‐related impacts and the trend towards increasing urbanization necessitates improvements to municipal climate change adaptation planning processes, which are a...
Conference Paper
Full-text available
Public transit networks are critical components of urban infrastructure threatened by climate change and related extreme weather events. These events include sudden, heavy precipitation, pluvial and fluvial flooding, and landslides , which can significantly affect network components like stops, switches, or track segments. The ongoing trend towards...
Patent
Full-text available
Techniques and systems are disclosed for receiving user input related to three co-optimized objectives, factors, or parameters, and translating the user input into weight factors for a tri-variable weighting function. In various embodiments, a triangular user interface element is displayed that allows a user to assign importance weights to three in...
Article
Full-text available
Urban population centers are especially vulnerable to extreme weather events and climate change. Local decision makers demand standardized processes, methods, and tools enabling them to design and implement climate adaptation strategies for their specific contexts. The project “Climate Resilient Cities and Infrastructures – RESIN” aims at providing...
Article
Timetable regularity, that is, equability of headways, is an important measure for service quality in high frequency public transit systems, assuring an evenly distributed passenger load as well as improving product attractiveness. However, to be feasible during daily operation a timetable may also have to adhere to other planning requirements, suc...
Conference Paper
Full-text available
Urban population centers are especially vulnerable to extreme weather events and climate change. Local decision makers demand standardized processes, methods, and tools enabling them to design and implement climate adaptation strategies for their specific contexts. The project “Climate Resilient Cities and Infrastructures – RESIN” aims at providing...
Article
Full-text available
Once planning and construction will be complete, Cologne’s new subway tunnel will enable fast and direct transportation between the central and southern urban quarters, and the city’s central station. This paper takes a closer look at the project’s four decades spanning history, its characteristics, and the impact of its integration on the overall...
Article
Full-text available
Typically, public transit modeling requires the availability of an extensive data basis to enable detailed modeling, calibration, and validation. Sometimes such data is not available, even though there is demand for a simulation model to examine the impacts of planning decisions and strategies. However, available data may support a simulation model...
Article
Full-text available
Especially suitable for the modeling and simulation of technical systems in a wider sense, discrete-event simulation is one of the most important and most versatile tools of the craft. Both students and practitioners should be familiar with its principles and mechanics, in particular if they are interested to look beyond their favorite modeling too...
Poster
Full-text available
A survey of existing data repositories to determine whether they meet the features and tools geared towards the long tail of computer science.
Patent
Techniques and systems for facilitating the calibration of oscillation frequencies for an analog audio synthesizer are disclosed. Included are embodiments for performing the initial calibration of an audio synthesizer and for continuously compensating for the frequency irregularities which originate from insufficient calibration and/or frequency dr...
Conference Paper
Full-text available
Extended Abstract We present initial investigation and requirements analysis results on Geo-Real, a location-based mobile app for real estate agents in Florida. The app will support real estate agents on-site, e.g. during showings, and while trav-eling. Through this project we explore new location-based services for realtors , and, eventually, for...
Poster
Full-text available
Parking guidance systems which provide information and recommendations on finding available parking in parking garages are significantly beneficial to users. These systems require calibration and evaluation before their application in the field. One way to accomplish this step is to evaluate them in a simulated environment. In this work, we report...
Article
Full-text available
Described is a simulation model of cruising for garage parking, intended both for the calibration and evaluation of real-time parking recommendation methods, and as a base for predictive guidance to available parking. The model combines the event-based and agent-based simulation approaches to represent the parking garage and the driver behavior. It...
Conference Paper
Parking guidance systems have to be calibrated and evaluated before their application in the field. One step to accomplish this is to evaluate them in a simulated environment. This paper presents a simple model of cruising for parking in a parking garage with focus on individual drivers’ behavior. While the described model itself is too basic to c...
Article
Full-text available
In public transit planning, regularity of timetables is seen as an important means to improve capacity efficiency by assuring an even trip distribution, as well as to improve product attractiveness and appreciation. This paper focuses on examining whether a regular timetable can also help to reduce network delay, especially resulting from inevitabl...
Technical Report
Full-text available
Like many other university courses, University of Cologne's programming class can be attended by differently sized teams, who handle presentations and homework collectively. Because students typically have tight schedules, it is preferable to give individual students the opportunity to weight the available time slot options according to their indiv...
Article
Full-text available
The city of Montpellier in the Languedoc-Roussillon region of France features a fast growing tram network as a central part of its public service infrastructure. Here, as in many other tram networks, resources like tracks and stations are shared between different lines. Because of the resulting dependencies, small inevitable delays can spread throu...
Conference Paper
Full-text available
Nicht in jedem Stadtbahnnetz ist Robustheit als Optimierungskriterium für Fahrpläne gleichsam geeignet. Im Rahmen dieses Beitrags werden deshalb Faktoren für die Netzstruktur bestimmt, die die Wirksamkeit von Robustheit als verspätungsmindernden Faktor beeinflussen. Anhand von Optimierungs- und Simulationsexperimenten auf Basis von Modellen der Sta...
Conference Paper
Full-text available
To be a feasible base for simulation studies of Cologne's tram network, a valid vehicle schedule has to consider several requirements, like multiple vehicle depots and multiple types of vehicles. The local transport provider utilizes both low-floor and high-floor vehicles, with high-floor vehicles being qualified to serve both high-floor and low-fl...
Conference Paper
Full-text available
To re-establish the regular driving operations of a tram network, which was disturbed significantly by unforeseen external events, traffic schedulers apply rescheduling and rerouting strategies. These strategies are usually multi-modal; they consider the interaction of trams, buses, even taxis. Thus, to evaluate the applicability of a given resched...
Article
Full-text available
To re-establish regular operations in a tram traffic network after a large disturbance, e.g. resulting from vehicle breakdown or station closure, the viability of several rescheduling and rerouting strategies has to be evaluated prior to their implementation. Here, a multi-modal traffic simulation system can help to enhance the decision quality. Su...
Conference Paper
Full-text available
Highly utilized tram networks, where multiple lines share tracks and stations, are inevitably affected by disturbances during daily operation. While consequences of small, local perturbations may be counteracted by schedule characteristics, e.g. robustness, long lasting disturbances have to be addressed by dispatchers via schedule adjustments. Seve...
Article
Full-text available
In mid-sized cities, tram networks are major components of public service infrastructure. In those networks with their typically dense schedules, multiple lines share tracks and stations, resulting in a dynamic system behavior and mounting delays following even small disruptions. Robustness is an important factor to keep delays from spreading throu...
Article
Full-text available
In many tram networks multiple lines share tracks and stations, thus requiring robust schedules which prevent inevitable delays from spreading through the network. Feasible schedules also have to fulfill various planning requirements originating from political and economical reasons. In this article we present a tool set designed to generate schedu...
Article
Full-text available
Almost half of Africa is covered by arid savannas, which are used as rangelands and are the source of livelihood for a vast population. To sustain pasture quality, degradation has to be avoided and efficient and sustainable land use strategies are needed. This paper describes the development of a simulation model representing the range management s...
Article
Full-text available
Interoperability among simulators is one of the key factors in distributed simulations. Several interoperability infrastructures such as HLA and DEVS/SOA have been utilised, but most of them do not provide any dynamics. This paper introduces the use of the OSGi service platform as universal middleware for dynamic distributed simulation of DEVS mode...
Conference Paper
Full-text available
Tour planning in multi-block layouts is a common exercise in logistics. In those systems, blocking effects result from conflicting agents competing for resources. Although clearly exceptional in real world applications, most methods of tour planning assume only one active agent, and thus do not consider blocking effects. In this paper we examine he...
Conference Paper
Full-text available
Im Folgenden werden die Auswirkungen des Einsatzes verschiedener Heuristiken zur Tourenplanung in manuellen Kommissionierstationen bei einem Pharmagroß-handel untersucht. Dabei wird nicht nur auf die Länge der Touren eingegangen, sondern zusätzlich die Auswirkung von Ressourcenkonflikten während der Kommis-sionierung auf die Dauer der Bedienzeiten...

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Projects

Projects (6)
Project
Purposefully designed systems like businesses or public administrations tend to become more complex during their lifetime, making them increasingly harder to manage effectively. In this project we design and evaluate methods and tools to assess and manage the organizational complexity of these "human-centric" models.
Archived project
IVAVIA is a standardized process for the assessment of climate change-related risks and vulnerabilities in cities and urban environments. It consists of seven modules aimed at supporting practitioners and end-users through the risk-based vulnerability assessment process, beginning with a systematic selection of hazards and drivers in their local context, and ending with a standardized presentation of the resulting outcomes to decision makers and stakeholders. IVAVIA offers a set of web-based software tools developed to support end-users executing the IVAVIA process.