VLDB 2026 Research / reviewers in the wild / expert
Ralf Krestel
dblp:60/3309
· DBLP profile ↗
33ranked-venue papers in the field
11as first author
14since 2021 · last 2026
0000-0002-5036-8589ORCID · verified
Domains — venue-derived; a paper can count in several
Information Retrieval & Web Search · 24 (8 first)Other / Interdisciplinary · 3 (3 first)Database Systems & Data Management · 2Data Mining & Knowledge Discovery · 2Knowledge Engineering, Semantic Web & Information Systems · 2
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | General Semantic Knowledge Infusion for Spatio-Temporal Traffic ForecastingabstractAlthough Graph Neural Networks (GNNs) have made significant advances in spatio-temporal traffic forecasting, their performance is limited when they rely solely on sensor proximity or road-network topology. This paper presents a spatio-temporal prediction framework, developed to incorporate knowledge in various forms. This framework aims to improve sensor-level, contextual understanding of the environment. A general-purpose knowledge graph (e.g., Wikidata) is used to create semantic subgraphs around traffic sensors and generate knowledge graph embeddings that capture meaningful relationships, such as nearby points of interest, administrative hierarchies, and the functional roles of locations. These embeddings are then fused with conventional traffic sensor graphs to provide additional adjacency matrices informed by semantics. This allows GNNs to learn the semantic context beyond physical connectivity. This study differs from previous research in two key ways. Firstly, rather than proposing a novel GNN architecture, it demonstrates the general impact of external knowledge on prediction accuracy. Secondly, experiments with well-established traffic forecasting approaches show that external knowledge provides additional information that street network data alone cannot convey. The results show that integrating data from general-purpose knowledge graphs and sensor networks through data fusion can enhance the prediction accuracy of traffic forecasting models, and offers a potential pathway toward improved interpretability. Mattis thor Straten, Yannick Wölker, Steffen Strohm, Prathvish Mithare, Ralf Krestel, Matthias Renz |
MDM | 5 |
| 2025 | 6th Workshop on Patent Text Mining and Semantic Technologies (PatentSemTech2025)abstractInformation retrieval systems for the patent domain have a long and evolving history, serving as effective tools to support patent experts in a variety of daily tasks.They facilitate patent landscape analysis, help in the drafting and evaluation tasks in the patenting process, and enable efficient information extraction to gain practical insights into new technologies and innovations.Moreover, they assist in identifying existing solutions, knowledge gaps, trends, and persistent challenges within specific technological fields, thereby informing strategic decision-making and innovation management.Advances in machine learning and natural language processing allow to further automate such tasks, e.g.paragraph retrieval, question answering (QA) or patent text generation.The exploration of semantic technologies for the intellectual property (IP) industry is still in its early stages, with significant potential yet to be unlocked.Investigating the use of artificial intelligence (AI) methods for the patent domain is therefore not only of academic interest, but also highly relevant for practitioners.Compared to other domains, high quality, semi-structured, annotated data is available in large volumes (a requirement for supervised machine learning models), making training large models easier.On the other hand, domain-specific challenges arise, such as very technical language or legal requirements for patent documents, and data from various disciplines and technological areas.With the 6th edition of this workshop we will provide a platform for researchers and industry to discuss recent developments for semantic patent retrieval and analysis employing sophisticated methods ranging from patent text mining, domain-specific information retrieval to large language models (LLMs) targeting next generation applications and use cases for the IP and related domains. Ralf Krestel, Hidir Aras, Linda Andersson, Florina Piroi, Allan Hanbury, Dean Alderucci |
SIGIR | 1 |
| 2024 | Comparative Analysis of Evaluation Measures for Scientific Text Simplification
Dennis Davari, Liana Ermakova, Ralf Krestel |
TPDL (1) | 3 |
| 2024 | Fine-Tuning BERT on Coarse-Grained Labels: Exploring Hidden States for Fine-Grained Classification
Aftab Anjum, Ralf Krestel |
NLDB (1) | 2 |
| 2024 | Shact: Disentangling and Clustering Latent Syntactic Structures from Transformer Encoders
Alejandro Sierra Múnera, Ralf Krestel |
NLDB (1) | 2 |
| 2024 | 5th Workshop on Patent Text Mining and Semantic Technologies (PatentSemTech2024)abstractInformation retrieval systems for the patent domain have a long history.They can support patent experts in a variety of daily tasks: from analyzing the patent landscape to support experts in the patenting process and large-scale information extraction.Advances in machine learning and natural language processing allow to further automate tasks, such as paragraph retrieval, question answering (QA) or even patent text generation.Uncovering the potential of semantic technologies for the intellectual property (IP) industry is just getting started.Investigating the use of artificial intelligence methods for the patent domain is therefore not only of academic interest, but also highly relevant for practitioners.Compared to other domains, high quality, semi-structured, annotated data is available in large volumes (a requirement for supervised machine learning models), making training large models easier.On the other hand, domain-specific challenges arise, such as very technical language or legal requirements for patent documents.With the 5th edition of this workshop we will provide a platform for researchers and industry to learn about novel and emerging technologies for semantic patent retrieval and big analytics employing sophisticated methods ranging from patent text mining, domain-specific information retrieval to large language models targeting next generation applications and use cases for the IP and related domains. Ralf Krestel, Hidir Aras, Linda Andersson, Florina Piroi, Allan Hanbury, Dean Alderucci |
SIGIR | 1 |
| 2023 | Domain-Specific Keyword Extraction using BERT
Jill Sammet, Ralf Krestel |
LDK | 2 |
| 2023 | 4th Workshop on Patent Text Mining and Semantic Technologies (PatentSemTech2023)abstractInformation retrieval systems for the patent domain have a long history. They can support patent experts in a variety of daily tasks: from analyzing the patent landscape to support experts in the patenting process and large-scale information extraction. Advances in machine learning and natural language processing allow to further automate tasks, such as paragraph retrieval or even patent text generation. Uncovering the potential of semantic technologies for the intellectual property (IP) industry is just getting started. Investigating the use of artificial intelligence methods for the patent domain is therefore not only of academic interest, but also highly relevant for practitioners. Compared to other domains, high quality, semi-structured, annotated data is available in large volumes (a requirement for supervised machine learning models), making training large models easier. On the other hand, domain-specific challenges arise, such as very technical language or legal requirements for patent documents. The focus of the 4th edition of this workshop will be on two-way communication between industry and academia from all areas of information retrieval in particular with the Asian community. We want to bring together novel research results and the latest systems and methods employed by practitioners in the field. Ralf Krestel, Hidir Aras, Linda Andersson, Florina Piroi, Allan Hanbury, Dean Alderucci |
SIGIR | 1 |
| 2022 | Discovering Fine-Grained Semantics in Knowledge Graph RelationsabstractKnowledge graphs (KGs) provide structured representation of data in the form of relations between different entities. The semantics of relations between words and entities are often ambiguous, where it is common to find polysemous relations that represent multiple semantics based on the context. This ambiguity in relation semantics also proliferates KG triples. While the guidance from custom-designed ontologies addresses this issue to some extent, our analysis shows that the heterogeneity and complexity of real-world data still results in substantial relation polysemy within popular KGs. The correct semantic interpretation of KG relations is necessary for many downstream applications such as entity classification and question answering. We present the problem of fine-grained relation discovery and a data-driven method towards this task that leverages the vector representations of the knowledge graph entities and relations available from relational learning models. We show that by performing clustering over these vectors, our method is able to not only identify the polysemous relations in knowledge graphs, but also discover the different semantics associated with them. Extensive empirical evaluation shows that fine-grained relations discovered by the proposed approach lead to substantial improvement in the semantics in the Yago and NELL datasets, as compared to baselines. Additional insights from qualitative analyses convey that fine-grained relation discovery is an important yet complex task, especially in the presence of complex ontologies and noisy data. Nitisha Jain, Ralf Krestel |
CIKM | 2 |
| 2022 | 3rd Workshop on Patent Text Mining and Semantic Technologies (PatentSemTech2022)abstractSteadily increasing numbers of patent applications per year and large amounts of available patent data necessitate highly efficient and interactive next-generation information retrieval systems in the patent domain. AI and Machine Learning (ML) methods such as Deep Learning (DL) are successfully adopted in many domains, so patent researchers and practitioners start to employ AI-based approaches as well, to support experts in the patenting process or to automate patent analysis and retrieval processes. AI-enhanced Information Retrieval systems can improve patent search and analysis but also require millions of annotated sample data for training the ML models. When working with patent data, particular challenges arise that call for adaption of existing IR and AI methods as well as development of novel approaches suited for the patent domain. The focus of the 3rd edition of this workshop will be on two-way communication between industry and academia from all areas of Information Retrieval, such as Natural Language Processing (NLP), Text and Data Mining (TDM), and Semantic Technologies (ST). We want to bring together novel research results and the latest systems and methods employed by the Intellectual Property (IP) industry. Ralf Krestel, Hidir Aras, Linda Andersson, Florina Piroi, Allan Hanbury, Dean Alderucci |
SIGIR | 1 |
| 2021 | Robust Visualisation of Dynamic Text Collections: Measuring and Comparing Dimensionality Reduction AlgorithmsabstractVisualisations are supposed to provide intuitive ways to explore large document collections. State-of-the-art approaches usually transform high-dimensional representations of documents into 2-dimensional vectors using dimensionality reduction algorithms. These vectors are then placed into a landscape hopefully retaining semantic information regarding similarity from the high-dimensional representation. Traditionally, dimensionality reduction algorithms are developed with static collections in mind. However, many "real-world" document collections, such as news articles, scientific literature, patents, Wikipedia, or tweets, to name a few, grow and evolve over time. Visualising the temporal change of these collections poses various challenges for out-of-the-box dimensionality reduction algorithms. Tim Repke, Ralf Krestel |
CHIIR | 2 |
| 2021 | Do Embeddings Actually Capture Knowledge Graph Semantics?
Nitisha Jain, Jan-Christoph Kalo, Wolf-Tilo Balke, Ralf Krestel |
ESWC | 4 |
| 2021 | 2nd Workshop on Patent Text Mining and Semantic Technologies (PatentSemTech2021)abstractInformation retrieval plays a crucial role in the patent domain. With the success of deep learning (DL) in other domains, patent practitioners and researchers are increasingly developing DL-based approaches to support experts in the patenting process or to automate processes for patent analysis. AI-enhanced information retrieval systems can improve patent search but also require lots of annotated data. When working with patent data, particular challenges arise that call for adaption and novel approaches of general IR and AI methods. with this workshop series we want to establish a two-way communication channel between industry and academia from relevant fields in information retrieval, such as natural language processing (NLP), text and data mining (TDM), and semantic technologies (ST), in order to explore and transfer new knowledge, methods and technologies for the benefit of industrial applications as well as support interdisciplinary research in applied sciences forthe intellectual property (IP) and neighbouring domains. Ralf Krestel, Hidir Aras, Linda Andersson, Florina Piroi, Allan Hanbury, Dean Alderucci |
SIGIR | 1 |
| 2021 | CrashNet: an encoder-decoder architecture to predict crash test outcomesabstractAbstract Destructive car crash tests are an elaborate, time-consuming, and expensive necessity of the automotive development process. Today, finite element method (FEM) simulations are used to reduce costs by simulating car crashes computationally. We propose CrashNet, an encoder–decoder deep neural network architecture that reduces costs further and models specific outcomes of car crashes very accurately. We achieve this by formulating car crash events as time series prediction enriched with a set of scalar features. Traditional sequence-to-sequence models are usually composed of convolutional neural network (CNN) and CNN transpose layers. We propose to concatenate those with an MLP capable of learning how to inject the given scalars into the output time series. In addition, we replace the CNN transpose with 2D CNN transpose layers in order to force the model to process the hidden state of the set of scalars as one time series. The proposed CrashNet model can be trained efficiently and is able to process scalars and time series as input in order to infer the results of crash tests. CrashNet produces results faster and at a lower cost compared to destructive tests and FEM simulations. Moreover, it represents a novel approach in the car safety management domain. Mohamed Karim Belaid, Maximilian Rabus, Ralf Krestel |
Data Min. Knowl. Discov. | 3 |
| 2020 | A Dataset of Journalists' Interactions with Their Readership: When Should Article Authors Reply to Reader Comments?abstractThe comment sections of online news platforms are an important space to indulge in political conversations and to discuss opinions. Although primarily meant as forums where readers discuss amongst each other, they can also spark a dialog with the journalists who authored the article. A small but important fraction of comments address the journalists directly, e.g., with questions, recommendations for future topics, thanks and appreciation, or article corrections. However, the sheer number of comments makes it infeasible for journalists to follow discussions around their articles in extenso. A better understanding of this data could support journalists in gaining insights into their audience and fostering engaging and respectful discussions. To this end, we present a dataset of dialogs in which journalists of The Guardian replied to reader comments and identify the reasons why. Based on this data, we formulate the novel task of recommending reader comments to journalists that are worth reading or replying to, i.e., ranking comments in such a way that the top comments are most likely to require the journalists' reaction. As a baseline, we trained a neural network model with the help of a pair-wise comment ranking task. Our experiment reveals the challenges of this task and we outline promising paths for future work. The data and our code are available for research purposes from: https://hpi.de/naumann/projects/repeatability/text-mining.html Julian Risch, Ralf Krestel |
CIKM | 2 |
| 2020 | Top Comment or Flop Comment? Predicting and Explaining User Engagement in Online News Discussions
Julian Risch, Ralf Krestel |
ICWSM | 2 |
| 2019 | Who is Mona L.? Identifying Mentions of Artworks in Historical Archives
Nitisha Jain, Ralf Krestel |
TPDL | 2 |
| 2018 | Beacon in the Dark: A System for Interactive Exploration of Large Email CorporaabstractThe large amount of heterogeneous data in these email corpora renders experts' investigations by hand infeasible. Auditors or journalists, e.g., who are looking for irregular or inappropriate content or suspicious patterns, are in desperate need for computer-aided exploration tools to support their investigations. Tim Repke, Ralf Krestel, Jakob Edding, Moritz Hartmann, Jonas Hering, Dennis Kipping, Hendrik Schmidt, Nico Scordialo, Alexander Zenner |
CIKM | 2 |
| 2018 | Bringing Back Structure to Free Text Email Conversations with Recurrent Neural Networks
Tim Repke, Ralf Krestel |
ECIR | 2 |
| 2017 | What Should I Cite? Cross-Collection Reference Recommendation of Patents and Papers
Julian Risch, Ralf Krestel |
TPDL | 2 |
| 2017 | Identifying Media Bias by Analyzing Reported SpeechabstractMedia analysis can reveal interesting patterns in the way newspapers report the news and how these patterns evolve over time. One example pattern is the quoting choices that media make, which could be used as bias indicators. Media slant can be expressed both with the choice of reporting an event, e.g. a person's statement, but also with the words used to describe the event. Thus, automatic discovery of systematic quoting patterns in the news could illustrate to the readers the media' beliefs, such as political preferences. In this paper, we aim to discover political media bias by demonstrating systematic patterns of reporting speech in two major British newspapers. To this end, we analyze news articles from 2000 to 2015. By taking into account different kinds of bias, such as selection, coverage and framing bias, we show that the quoting patterns of newspapers are predictable. Konstantina Lazaridou, Ralf Krestel, Felix Naumann |
ICDM | 2 |
| 2016 | Topic Shifts in StackOverflow: Ask it Like Socrates
Toni Grütze, Ralf Krestel, Felix Naumann |
NLDB | 2 |
| 2013 | Topic Cropping: Leveraging Latent Topics for the Analysis of Small Corpora
Nam Khanh Tran, Sergej Zerr, Kerstin Bischoff, Claudia Niederée, Ralf Krestel |
TPDL | 5 |
| 2013 | Recommending patents based on latent topicsabstractThe availability of large volumes of granted patents and applications, all publicly available on the Web, enables the use of sophisticated text mining and information retrieval methods to facilitate access and analysis of patents. In this paper we investigate techniques to automatically recommend patents given a query patent. This task is critical for a variety of patent-related analysis problems such as finding relevant citations, research of relevant prior art, and infringement analysis. We investigate the use of latent Dirichlet allocation and Dirichlet multinomial regression to represent patent documents and to compute similarity scores. We compare our methods with state-of-the-art document representations and retrieval techniques and demonstrate the effectiveness of our approach on a collection of US patent publications. Ralf Krestel, Padhraic Smyth |
RecSys | 1 |
| 2012 | iParticipate: Automatic Tweet Generation from Local Government Data
Christoph Lofi, Ralf Krestel |
DASFAA (2) | 2 |
| 2012 | Reranking web search results for diversity
Ralf Krestel, Peter Fankhauser |
Inf. Retr. | 1 |
| 2011 | Diversifying Product Review Rankings: Getting the Full PictureabstractE-commerce Web sites owe much of their popularity to consumer reviews provided together with product descriptions. On-line customers spend hours and hours going through heaps of textual reviews to build confidence in products they are planning to buy. At the same time, popular products have thousands of user-generated reviews. Current approaches to present them to the user or recommend an individual review for a product are based on the helpfulness or usefulness of each review. In this paper we look at the top-k reviews in a ranking to give a good summary to the user with each review complementing the others. To this end we use Latent Dirichlet Allocation to detect latent topics within reviews and make use of the assigned star rating for the product as an indicator of the polarity expressed towards the product and the latent topics within the review. We present a framework to cover different ranking strategies based on the user's need: Summarizing all reviews, focus on a particular latent topic, or focus on positive, negative or neutral aspects. We evaluated the system using manually annotated review data from a commercial review Web site. Ralf Krestel, Nima Dokoohaki |
Web Intelligence | 1 |
| 2010 | Semantic Content Access Using Domain-Independent NLP Ontologies
René Witte, Ralf Krestel |
NLDB | 2 |
| 2010 | Exploiting click-through data for entity retrievalabstractWe present an approach for answering Entity Retrieval queries using click-through information in query log data from a commercial Web search engine. We compare results using click graphs and session graphs and present an evaluation test set making use of Wikipedia "List of" pages. Bodo Billerbeck, Gianluca Demartini, Claudiu S. Firan, Tereza Iofciu, Ralf Krestel |
SIGIR | 5 |
| 2010 | Language Models and Topic Models for Personalizing Tag RecommendationabstractMore and more content on the Web is generated by users. To organize this information and make it accessible via current search technology, tagging systems have gained tremendous popularity. Especially for multimedia content they allow to annotate resources with keywords (tags) which opens the door for classic text-based information retrieval. To support the user in choosing the right keywords, tag recommendation algorithms have emerged. In this setting, not only the content is decisive for recommending relevant tags but also the user's preferences. In this paper we introduce an approach to personalized tag recommendation that combines a probabilistic model of tags from the resource with tags from the user. As models we investigate simple language models as well as Latent Dirichlet Allocation. Extensive experiments on a real world dataset crawled from a big tagging system show that personalization improves tag recommendation, and our approach significantly outperforms state-of-the-art approaches. Ralf Krestel, Peter Fankhauser |
Web Intelligence | 1 |
| 2010 | Why finding entities in Wikipedia is difficult, sometimes
Gianluca Demartini, Claudiu S. Firan, Tereza Iofciu, Ralf Krestel, Wolfgang Nejdl |
Inf. Retr. | 4 |
| 2009 | Latent dirichlet allocation for tag recommendationabstractTagging systems have become major infrastructures on the Web. They allow users to create tags that annotate and categorize content and share them with other users, very helpful in particular for searching multimedia content. However, as tagging is not constrained by a controlled vocabulary and annotation guidelines, tags tend to be noisy and sparse. Especially new resources annotated by only a few users have often rather idiosyncratic tags that do not reflect a common perspective useful for search. In this paper we introduce an approach based on Latent Dirichlet Allocation (LDA) for recommending tags of resources in order to improve search. Resources annotated by many users and thus equipped with a fairly stable and complete tag set are used to elicit latent topics to which new resources with only a few tags are mapped. Based on this, other tags belonging to a topic can be recommended for the new resource. Our evaluation shows that the approach achieves significantly better precision and recall than the use of association rules, suggested in previous work, and also recommends more specific tags. Moreover, extending resources with these recommended tags significantly improves search for new resources. Ralf Krestel, Peter Fankhauser, Wolfgang Nejdl |
RecSys | 1 |
| 2008 | Predicting News Story Importance Using Language FeaturesabstractIn this age of awareness, people have access to information like never before. Hundreds of newspapers and millions of bloggers present news and their interpretations in an openly accessible manner. With globalization, distant events can have impact on people thousands of miles away. While expert humans can recognize a potentially important piece of news, this is still a difficult problem for an automatic system. Since people are increasingly relying on multiple online sources of information, it is important to support users in filtering news automatically. In this work, we consider the problem of anticipating news story importance, i.e. given a news item, predicting if it will be of interest for a majority of users. Such ranking is currently done manually for newspapers, and we explore automatic approaches and indicative features for the same. Our main conclusion is that importance prediction is a hard problem, and pure textual features are not sufficient for classifiers with 90% accuracy. Ralf Krestel, Bhaskar Mehta |
Web Intelligence | 1 |