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Die vorliegende Arbeit beschäftigt sich im übergeordneten Kontext mit den Bounding Volume Hierarchies zur Veinfachung des Intersection Testings beim Raytracing. Die derzeitige Problematik besteht vor allem in der immer noch zu optimierenden Laufzeit. Dementsprechend wird trotz der bereits bestehenden Beschleunigungsdatenstrukturen wie unter anderem der Bounding Volume Hierarchy versucht, effizientere Strukturen oder Erstellungsprozeduren zu entwickeln. Für die Bounding Volume Hierarchy bedeutet dies, dass vor allem hinsichtlich verschiedener Splitting-Methoden und Möglichkeiten für die Baumoptimierung geforscht wird. Explizit wird daher innerhalb dieser Arbeit untersucht, wie die Bounding Volume Hierarchy durch die Verwendung der Hauptkomponentenanalyse bei der Erstellung optimiert werden kann und wie effizient der daraus resultierende Ansatz gegenüber der klassischen Bounding Volume Hierarchy sowie deren Splitting-Methoden ist. Eine Evaluation anhand 12 verschiedener Szenen zeigte, dass der vorliegende Ansatz unter Verwendung der SAH-Methode wie auch mit der Middle-Methode 17.70% respektive 13.14% geringere Renderlaufzeiten als der distanzbasierte Ansatz aufweist. Des Weiteren konnte mittels der kombinierten Verwendung aus klassischer SAH-Methode und PCA-basierter SAH-Methode eine weitere Verbesserung um 6.65% gegenüber der SAH-Methode der PCA-BVH erreicht werden.
Soils are complex, evolving systems that simultaneously shape and are shaped by numerous biotic and abiotic factors in a vast web of interactions that creates the conditions for the propagation of life and the maintenance of human societies. Yet, land use and land use change (LULUC) and anthropogenic climate change (CC) are forcing substantial and rapid alterations into soil’s properties and processes, thus affecting the functions and services derived from it. The resulting land degradation (LD) is now spread, according to recent estimates, over nearly 30 % of the world’s total land, mostly on the population dense and impoverished tropics, a zone predicted to withstand the worst impacts of CC. The Atlantic Forest in Brazil is a particularly vulnerable environment, and the unusual drought of 2014-2017 that hit its Southeastern region is likely the harbinger of a progressively drier future.
The way the prelude of what might be an increasingly frequent hazard affected farmers’ livelihoods and natural resources, and the manner in which they reacted to those impacts can thus reveal points of strength and fragility that could be respectively harnessed or addressed to develop a more sustainable agriculture and climate resilience. This master thesis focused on characterizing those impacts and reactions on distinct dairy production systems in two municipalities in Northwestern Rio de Janeiro: Santo Antônio de Pádua and Cambuci. Through interviews and in loci observations, the researcher collected data concerning environmental services (erosion prevention, soil cover and water provision), production variables (inputs and outputs), socio-economic information, farm system management and farmers’ future perspectives. The results show that dairy production systems in the region are heterogeneous and, although they may share common characteristics, drought outcomes were closely tied to the specificities of each farm. Ultimately, outcomes originated from differences in water supply, water demand, and feed availability, their subsequent change by the drought and farmers’ reaction to those changes at each property.
Achieving urban water security is a major challenge for many countries. While several studies have assessed water security at a regional level, many studies have also emphasized the lack of assessment of water security and application of measures to achieve it at the urban level.
Recent studies that have focused on measuring urban water security are not holistic, and there is still no agreed-upon understanding of how to operationalize and identify an assessment framework to measure the current state and dynamics of water security. At present, there is also no clearly defined and widely endorsed definition of urban water security. To address this challenge, this study provides a systematic approach to better understand urban water security, with a working definition and an assessment framework to be applied in peri-urban and urban areas. The proposed working definition of urban water security is based on the United Nations (UN) sustainable development goal on water and sanitation and the human rights on water and sanitation. It captures issues of urban-level technical, environmental, and socio-economic indicators that emphasize credibility, legitimacy, and salience.
The assessment framework depends on four main dimensions to achieve urban water security: Drinking water and human beings, ecosystem, climate change and water-related hazards, and socio-economic factors (DECS). The framework further enables the analysis of relationships and trade-off between urbanization and water security, as well as between DECS indicators. Applying this framework will help governments, policy-makers, and water stakeholders to target scant resources more eff ectively and sustainably. The study reveals that achieving urban water security requires a holistic and integrated approach with collaborative stakeholders to provide a meaningful way to improve understanding and managing urban water security.
Ecosystems provide a wide range of goods, services or ecosystem services (ES) to society. Estimating the impact of land use and land cover (LULC) changes on ES values (ESV) is an important tool to support decision making. This study used remote sensing and GIS tools to analyze LULC change and transitions from 2001 to 2016 and assess its impact on ESV in a tropical forested landscape in the southern plains of Nepal. The total ESV of the landscape for the year 2016 is estimated at USD 1264 million year−1. As forests are the dominant land cover class and have high ES value per hectare, they have the highest contribution in total ESV. However, as a result of LULC change (loss of forests, water bodies, and agricultural land), the total ESV of the landscape has declined by USD 11 million year−1. Major reductions come from the loss in values of climate regulation, water supply, provision of raw materials and food production. To halt the ongoing loss of ES and maintain the supply and balance of different ES in the landscape, it is important to properly monitor, manage and utilize ecosystems. We believe this study will inform policymakers, environmental managers, and the general public on the ongoing changes and contribute to developing effective land use policy in the region.
The climate is changing and this increases the risk of climate threats, which is affecting the most vulnerable populations, mainly peasant farmers. In order to minimize impacts on these populations, interest has been aroused to develop strategies that increase their resilience to climate-related risks. This issue has been little addressed in Ecuador, despite the increased frequency and intensity of climate-related risks, which are directly affecting agroecosystems and farmers' livelihoods. This research addresses the resilience of farmers to climate risks in the canton of Pedro Carbo, an area located on the Ecuadorian coast of Guayas Province characterized by a high rate of poverty and dedicated mainly to agriculture.
The overall objective of this research was to carry out an analysis of the resilience of small farmers to climate risks, as well as to recommend adaptation/transformation strategies to increase their resilience to climate. For this, farmers' perceptions were considered, as well as the opinion of experts on the subject. Multiple methods were applied such as: literature review, map generation, household surveys, participatory workshops with farmers and interviews with experts. In addition, a multidimensional matrix was developed to analyze quantitative and qualitative data through indicators that measure resilience in the study area. The main findings in this research reflect that farmers have very low resilience due to their socioeconomic characteristics, agricultural practices, lack of infrastructure and technologies, weak community organizations, limited access to credit and insurance, as well as lack of capacity building and technical assistance. Finally, recommendations for strategies to support planning and decision-making were developed.
Keywords: climate-related risks, peasant family farming, resilience, resilience assessment, climate resilience, farmers perceptions, Pedro Carbo
While global food production greatly exceeds dietary energy demand, undernutrition remains, and diets largely fail to ensure the health of the population. Agricultural biodiversity is crucial for the world’s food security, but genetic diversity has been degraded. In Mexico, the dietary transition towards processed foods has contributed to malnutrition and a rise of diet-related chronic diseases. Mexico’s indigenous people are conserving and creating valuable plant genetic resources in their swidden milpas and traditional agroforestry systems but remain the country’s most vulnerable population group. The Teenek (or Huastec), an indigenous group that habitat the Huasteca Potosina, a region in north-eastern Mexico cultivate a high diversity of edible plants in their home gardens (solar), milpas, and agroforestry systems (te’lom, or finca). However, migration has been leading to the abandonment of traditional farming in the region.
The objective of this study was to analyse if the managed agricultural biodiversity of the different traditional land use systems contributes to the food security of the farming households in the community of Jol Mom. Food availability and access were investigated. In total, 40 households were surveyed. Dietary patterns were identified through principal component analysis. Informal interviews, semi-structured interviews and participant observation allowed to account for the people’s own perceptions and provided additional insights. Findings showed that traditional Teenek farming systems are the source of a variety of nutritious foods and resulted to be the most important provider of fruits and vegetables. The average production diversity was 34 out of 56 crops, farmers cultivating more than one or two farming systems showed an increase of four and 11 produced species respectively. Production diversity was strongly correlated with food variety in a household’s diet, with an increment of one per 0.85 produced crop. Two main diverging dietary patterns were revealed, a westernized diet relying largely on purchased foods, to which the younger generation was more inclined, and a traditional diet characterized by a high consumption of cultivated products, mostly observed in the older households.
In conclusion, farming households in Jol Mom profit from the agricultural diversity of their production systems, either through the consumption of nutritious foods or by the sale of agricultural products. However, a tendency towards nutrient-poor diets was observed. Increasing agricultural diversity and consumption of locally produced foods might help to fight this trend but would require a valorisation of traditional foods and an appreciation of the contribution of indigenous people’s traditional agriculture to food security.
Proceedings des Researchers‘ Corner zur 12. Jahrestagung des Förderkreises Rückversicherung 2019
(2019)
Am 5. Juli 2019 fand die 12. Jahrestagung des Förderkreises Rückversicherung in Niederkassel bei Köln statt. Etwa 80 Repräsentanten der in dem Förderkreis mitwirkenden (Rück-) Versicherungsunternehmen und Gäste nahmen daran teil. Im Rahmen der Jahrestagung wurde zum fünften Mal der Researchers‘ Corner durchgeführt, in dessen Verlauf acht der in der Kölner Forschungsstelle
Rückversicherung beschäftigten wissenschaftlichen Mitarbeiter*innen einen Vortrag zu dem jeweilig aktuell bearbeiteten Forschungsprojekt hielten.
In drei Sessions – mit je 2-3 parallel gehaltenen Vorträgen mit Poster – wurden die wichtigsten Ergebnisse der wissenschaftlichen Untersuchungen der Kölner
Forschungsstelle Rückversicherung präsentiert und diskutiert. Die Heterogenität der vorgetragenen Themen der wissenschaftlichen Mitarbeiter*innen spiegelt die
Verzahnung der Kölner Forschungsstelle mit der Rückversicherungspraxis wider.
Session 1
a) Manuel Dietmann (M.Sc.): Zunehmende Bedeutung der
Risikomanagementfunktion in Versicherungsunternehmen
b) Robert Joniec (M.Sc., FCII, cand. PhD): Wie geht es dem Rückversicherungs-Zyklus?
c) Wolfgang Koch (M.Sc., FCII): Informationsasymmetrien
zwischen Rückversicherungsmaklern und Zedenten
Session 2
a) Jörg Dirks (M.Sc., FCII): Unbemannte Fluggeräte
– Evolution des Luftfahrt-(Rück-)Versicherungsmarktes
b) Fabian Lassen (M.Sc., FCII): Senkung der Volatilität durch Einsatz eines versicherungstechnischen Swaps
c) Fabian Pütz (M.Sc., cand. PhD): Transfer von Cat-Risiken von Schwellenländern aus volkswirtschaftlicher Perspektive
Session 3
a) Kai-Olaf Knocks (M.A., FCII): Der ILS-Markt 2019 – abgeschreckt oder abwartend?
b) Lihong Wang (M.Sc., FCII, cand. PhD): China InsurTech Development
Mit der Veröffentlichungsreihe „Proceedings des Researchers‘ Corner“ entspricht die Kölner Forschungsstelle Rückversicherung dem Wunsch, die
Forschungsergebnisse unserer Wissenschaftler*innen sowie die entsprechenden Poster und Diskussionen zu publizieren. Dabei werden die Titel gemäß der oben
aufgeführten Agenda des Researchers‘ Corner der 12. Jahrestagung des Förderkreises Rückversicherung wiedergegeben. Im Rahmen der Veranstaltung führte Herr Prof. Materne des Weiteren ein Interview mit Herrn Ingo Wichelhaus (Senior Director, Mount Street) zum Thema Risiko- und Portfoliomanagement. Hierbei wurde insbesondere auf das breite Risikospektrum von Finanzierungen im Schifffahrtssektor eingegangen.
Unser Dank gilt den Fördermittelgebern, die sowohl diese Veranstaltung als auch die Forschung der Wissenschaftler*innen erst ermöglichen.
Grasping and manipulation with anthropomorphic robotic and prosthetic hands presents a scientific challenge regarding mechanical design, sensor system, and control. Apart from the mechanical design of such hands, embedding sensors needed for closed-loop control of grasping tasks remains a hard problem due to limited space and required high level of integration of different components. In this paper we present a scalable design model of artificial fingers, which combines mechanical design and embedded electronics with a sophisticated multi-modal sensor system consisting of sensors for sensing normal and shear force, distance, acceleration, temperature, and joint angles. The design is fully parametric, allowing automated scaling of the fingers to arbitrary dimensions in the human hand spectrum. To this end, the electronic parts are composed of interchangeable modules that facilitate the echanical scaling of the fingers and are fully enclosed by the mechanical parts of the finger. The resulting design model allows deriving freely scalable and multimodally sensorised fingers for robotic and prosthetic hands. Four physical demonstrators are assembled and tested to evaluate the approach.
Sensors can monitor physical attributes and record multimodal data in order to provide feedback. The application calligraphy trainer, exploits these affordances in the context of handwriting learning. It records the expert’s handwriting performance to compute an expert model. The application then uses the expert model to provide guidance and feedback to the learners.
However, new learners can be overwhelmed by the feedback as handwriting learning is a tedious task. This paper presents the pilot study done with the calligraphy trainer to evaluate the mental effort induced by various types of feedback provided by the application. Ten participants, five in the control group and five in the treatment group, who were Ph.D. students in the technology-enhanced learning domain, took part in the study. The participants used the application to learn three characters from the Devanagari script. The results show higher mental effort in the treatment group when all types of feedback are provided simultaneously. The mental efforts for individual feedback were similar to the control group. In conclusion, the feedback provided by the calligraphy trainer does not impose high mental effort and, therefore, the design considerations of the calligraphy trainer can be insightful for multimodal feedback designers.
Web browsers use HTTP caches to reduce the amount of data to be transferred over the network and allow Web pages to load faster. Content such as scripts, images, and style sheets, which are static most of the time or shared across multiple websites, are stored and loaded locally when recurring requests ask for cached resources. This behaviour can be exploited if the cache is based on a naive implementation. This paper summarises possible attacks on the browser cache and shows through extensive experiments that even modern web browsers still do not provide enough safeguards to protect their users. Moreover, the available built-in as well as addable cache controls offer rather limited functionality in terms of protection and ease of use. Due to the volatile and inhomogeneous APIs for controlling the cache in modern browsers, the development of enhanced user-centric cache controls remains -until further notice- in the hands of browser manufacturers.
The ‘Energy Crisis’ has become the talk of the town in pretty much every developing and lower developing countries in today’s world. It is characterized by a state where the country’s locally available energy resources are being depleted and it is dependent on imported fuel. The problem is considered as although not parallel, but a descendant of the food crisis in terms of the seriousness of the problems in developing nations essentially in Sub-Saharan Africa (SSA). Ethiopia is one such country which nevertheless going through a rapid scale of development (nearly 11 % annual growth rate as of 2017 according to the World Bank) and also is endowed with an enormous amount of natural resources such as hydro, wind, solar, geothermal energy potential. The Ethiopian power sector is heavily dependent on the country’s hydropower resources. However, it needs to diversify its energy sector and integrate new and other renewable energy sources because, in the longer term, its extreme hydropower dependence may put its power sector vulnerable to natural risks like droughts which are very likely scenarios due to the climate change. Since the lack of access to modern forms of energy services left no choice for the Ethiopians than to continue their traditional biomass use, and it results in unsustainable environmental harm with deforestation, soil erosion, and many others. To address this issue, Ethiopia is taking necessary steps towards climate-friendly industrialization of the economy.
In order to understand this transition, a socio-technical analysis of Ethiopian ambitious transformation from an agrarian society to a climate resilient green society has been presented in this paper. An analytical framework will be formulated as a prerequisite for the study by introducing the theory of Multilevel Perspective (MLP). This theory enables the understanding of three different levels of socio-technical environment namely niches, regime, and landscape in which the respective actors interact with each other to facilitate the process of transition. As a part of laying the groundwork, this thorough analysis constitutes all the country’s energy-related activities and associated energy demands, conversion technologies, current fuel mix, primary energy resources, and energy policies in the Ethiopian energy system. The LEAP analysis results from Mr. Md Alam Mondal and group are summarized to obtain an understanding of the country’s total energy demand scenarios.
Consequently, the actors from each socio-technical level have been identified in the context of Ethiopia and their dynamics of interaction have been explained in order to understand the process of energy system transition of Ethiopia in the direction of diversification of its energy system and hence result in the expansion of new renewable energy sector. Most importantly the assessment suggests that the transition process is majorly driven by top-down forces and intra-level reconfiguration of regime actors. There are no bottom-up forces acting as only a little research and development work takes place in the country to develop new radical changes/technological niches. A developing country like Ethiopia has undoubtedly a bright future ahead with all systems in place and the nature-gifted natural resource potential. The ambitious goals set by the country and the international help from developed allies are definitely working in tandem to ensure their accomplishment. With its guiding vision towards development and the global climate change movement, Ethiopia surely has the potential to lead by example.
Die 11. Jahrestagung des Förderkreises Rückversicherung zum Thema Rückversicherung fand am 13. Juli 2018 in Niederkassel bei Köln statt. Etwa 85 eingeladene Repräsentanten aus dem Förderkreis unterstützenden (Rück-)Versicherungsunternehmen und Gäste nahmen daran teil.
Im Rahmen der Jahrestagung wurde zum vierten Mal der Researchers‘ Corner durchgeführt, in dessen Verlauf acht der in der Kölner Forschungsstelle Rückversicherung beschäftigten Wissenschaftlichen Mitarbeiter einen Vortrag zu dem jeweilig individuell bearbeiteten Forschungsprojekt hielten. Des Weiteren wurden von Prof. Materne Interviews mit den Herren Dr. Falk Niehörster (Climate Risk Innovations) und Dr. Magnus Kobel (YAS.life) geführt. Dr. Niehörster berichtete über seine Forschungen und Beratungstätigkeit hinsichtlich der maritimen Klimaveränderung und Dr. Kobel über das Geschäftsmodell seines InsurTecs YAS.life und seine allgemeinen Erfahrungen bei Gründung und Entwicklungen von Start-ups.
In drei Sessions – mit je 2-3 jeweils drei parallel laufenden Vorträgen mit Poster – wurden die wichtigsten Ergebnisse der wissenschaftlichen Untersuchungen der Kölner Forschungsstelle Rückversicherung präsentiert und diskutiert. Die Heterogenität in den vorgetragenen Themen der wissenschaftlichen Mitarbeiter spiegelt die Verzahnung der Forschungstheorie mit der Praxistätigkeit wider.
This project is focused on the generation of hardware independent code for PLCs and the comparison for energy consumption patterns of hydraulic and electric drive unit. This works is dedicated to MLC (mould level control) in a continuous casting machine, which is used to cast steel slabs continuously. The code generation is done with the help of the PLC coder which is present in the software Simulink. The programming is done entirely in MATLAB. The application of the generated code is tested on the Siemens S7-1500 PLC. For executing the code and the development of the HMI (human machine
interface) Siemens software TIA Portal V15 has been used. Moreover, for further analysis of signals and testing the code, a PDA or process data acquisition system, IBA system is used. For energy analysis also the IBA system is used.
La Picasa basin, an interjurisdictional endorreic basin of 5282 km2 located in the “Central Pampa” in Argentina, has suffered repeated flooding caused by an increasing water level of La Picasa lagoon, affecting livelihoods, infrastructure, transportation and agriculture. Although water infrastructure has been built to regulate water excesses, it has not been effective in reducing the flood risk.
To improve the knowledge of the hydrological system, the master’s thesis aimed to develop a water balance model of La Picasa lagoon at a monthly time step between the hydrological years 2007/2008 and 2016/2017. Specifically, the objectives were to identify and quantify the most important components and processes determining its water level, area and volume and to propose hypothetical simulation scenarios based on different pumping operation schemes.
The description of the conceptual model and implementation of a sensitivity analysis allowed to identify the inflow and outflow components of the water balance and quantify their relative contributions, namely precipitation, water discharge from channels, surface runoff from surrounding sub-basins of the lagoon, evaporation and pumping. The performance tests applied to the model during the calibration and validation showed a very good performance. Additionally, two simulation scenarios were proposed, namely potential pumping and adjusted pumping, which reflected different trajectories of the water balance.
The master’s thesis concluded that precipitation and evaporation were the most determinant inflow and outflow components in the water balance of La Picasa lagoon respectively. However, the flooding event in 2016/2017 was caused by a simultaneous reduction of net evaporation and an increase in water discharge, surface runoff and intermittent pumping. The simulation scenarios suggested that an optimal operation of the pumping stations could have been effective to increase the storage capacity of the lagoon. However, during longer humid periods, it might not be enough to outweigh additional inflows.
Editorial
(2020)
One-step preparation of bilayered films from kraft lignin and cellulose acetate to mimic tree bark
(2020)
This contribution presents the development of a dry-cast method for the one-step preparation of bio-based films from wood polymers that mimic the bilayered structure of tree bark, the natural protective layer of the tree. In a simplified view, natural bark can be considered as the superposition of an external homogeneous and non-porous layer (outer bark) and a porous substructure layer (inner bark). This work is a first step for the future development of bio-based biomimetic wood coatings. The film had a bark-like appearance and its total density, bulk density and porosity were similar to values measured in natural bark. Furthermore, the structural characteristics of the studied film, namely specific surface area (BET) and pore size distribution, as well as the performance of the water adsorption ability were investigated and discussed.
This paper introduces CAAI, a novel cognitive architecture for artificial intelligence in cyber-physical production systems. The goal of the architecture is to reduce the implementation effort for the usage of artificial intelligence algorithms. The core of the CAAI is a cognitive module that processes the user’s declarative goals, selects suitable models and algorithms, and creates a configuration for the execution of a processing pipeline on a big data platform. Constant observation and evaluation against performance criteria assess the performance of pipelines for many and different use cases. Based on these evaluations, the pipelines are automatically adapted if necessary. The modular design with well-defined interfaces enables the reusability and extensibility of pipeline components. A big data platform implements this modular design supported by technologies such as Docker, Kubernetes, and Kafka for virtualization and orchestration of the individual components and their communication. The implementation of the architecture is evaluated using a real-world use case. The prototypic implementation is accessible on GitHub and contains a demonstration.
The paper presents results of the modelling of heat transfer at film boiling of a liquid in a porous medium on a vertical heated wall bordering with the porous medium. Such processes are observed at cooling of high-temperature surfaces of heat pipes, microstructural radiators etc. Heating conditions at the wall were the constant wall temperature or heat flux. The outer boundary of the vapor film was in contact with moving or stationary liquid inside the porous medium. An analytical solution was obtained for the problem of fluid flow and heat transfer using the porous medium model in the Darcy–Brinkman and Darcy–Brinkman–Forchheimer approximation. It was shown that heat transfer at film boiling in a porous medium was less intensive than in the absence of a porous medium (free fluid flow) and further decreased with the decreasing permeability of the porous medium. Significant differences were observed in frames of both models: 20% for small Darcy numbers at Da < 2 for the Darcy–Brinkman model, and 80% for the Darcy–Brinkman–Forchheimer model. In the Darcy–Brinkman model, depending on the interaction conditions at the vapor–liquid interface (no mechanical interaction or stationary fluid), a sharp decrease in heat transfer was observed for the Darcy numbers lower than five. The analytical predictions of heat transfer coefficients qualitatively agreed with the data of Cheng and Verma (Int J Heat Mass Transf 24:1151–1160, 1981) though demonstrated lower values of heat transfer coefficients for the conditions of the constant wall temperature and constant wall heat flux.
Stable recombinant mammalian cells are of growing importance in pharmaceutical biotechnology production scenarios for biologics such as monoclonal antibodies, growth and blood factors, cytokines and subunit vaccines. However, the establishment of recombinant producer cells using classical stable transfection of plasmid DNA is hampered by low stable gene transfer efficiencies. Consequently, subsequent selection of transgenic cells and the screening of clonal cell populations are time- and thus cost-intensive. To overcome these limitations, expression cassettes were embedded into transposon-derived donor vectors. Upon the co-transfection with transposase-encoding constructs, elevated vector copy numbers stably integrated into the genomes of the host cells are readily achieved facilitating under stringent selection pressure the establishment of cell pools characterized by sustained and high-yield recombinant protein production. Here, we discuss some aspects of transposon vector technologies, which render these vectors promising candidates for their further utilization in the production of biologics.
Academic search systems aid users in finding information covering specific topics of scientific interest and have evolved from early catalog-based library systems to modern web-scale systems. However, evaluating the performance of the underlying retrieval approaches remains a challenge. An increasing amount of requirements for producing accurate retrieval results have to be considered, e.g., close integration of the system’s users. Due to these requirements, small to mid-size academic search systems cannot evaluate their retrieval system in-house. Evaluation infrastructures for shared tasks alleviate this situation. They allow researchers to experiment with retrieval approaches in specific search and recommendation scenarios without building their own infrastructure. In this paper, we elaborate on the benefits and shortcomings of four state-of-the-art evaluation infrastructures on search and recommendation tasks concerning the following requirements: support for online and offline evaluations, domain specificity of shared tasks, and reproducibility of experiments and results. In addition, we introduce an evaluation infrastructure concept design aiming at reducing the shortcomings in shared tasks for search and recommender systems.