9607 research outputs found
Sort by
No Silver Bullet:Towards Demonstrating Secure Software Development for Small and Medium Enterprises in a Business-to-Business Model
Get PDFSoftware developing small and medium enterprises (SMEs) play a crucial role as suppliers to larger corporations and public administration. It is therefore necessary for them to be able to demonstrate that their products meet certain security criteria, both to gain trust of their customers and to comply to standards that demand such a demonstration. In this study we have investigated ways for SMEs to demonstrate their security when operating in a business-to-business model, conducting semi-structured interviews (N=16) with practitioners from different SMEs in Denmark and validating our findings in a follow-up workshop (N=6). Our findings indicate five distinctive security demonstration approaches, namely: Certifications, Reports, Questionnaires, Interactive Sessions and Social Proof. We discuss the challenges, benefits, and recommendations related to these approaches, concluding that none of them is a one-size-fits all solution and that more research into relative advantages of these approaches and their combinations is needed
What Monads Can and Cannot Do with a Few Extra Pages
Get PDFAbstract. The delay monad provides a way to introduce general recursion in type theory. To write programs that use a wide range of computational effects directly in type theory, we need to combine the delay monad with the monads of these effects. Here we present a first systematic study of such combinations.We study both the coinductive delay monad and its guarded recursive cousin, giving concrete examples of combining these with well-known computational effects. We also provide general theorems stating which algebraic effects distribute over the delay monad, and which do not. Lastly, we salvage some of the impossible cases by considering distributive laws up to weak bisimilarity.<br/
From Theory to Practice: Engineering Approximation Algorithms for Dynamic Orientation.
No full textDynamic graph algorithms have seen significant theoretical advancements, but practical evaluations often lag behind. This work bridges the gap between theory and practice by engineering and empirically evaluating recently developed approximation algorithms for dynamically maintaining graph orientations. We comprehensively describe the underlying data structures, including efficient bucketing techniques and round-robin updates. Our implementation has a natural parameter λ, which allows for a trade-off between algorithmic efficiency and the quality of the solution. In the extensive experimental evaluation, we demonstrate that our implementation offers a considerable speedup. Using different quality metrics, we show that our implementations are very competitive and can outperform previous methods. Overall, our approach solves more instances than other methods while being up to 112 times faster on instances that are solvable by all methods compared
Simpler Universally Optimal Dijkstra.
No full textLet G be a weighted (directed) graph with n vertices and m edges. Given a source vertex s, Dijkstra’s algorithm computes the shortest path lengths from s to all other vertices in O(m + n log n) time. This bound is known to be worst-case optimal via a reduction to sorting. Theoretical computer science has developed numerous fine-grained frameworks for analyzing algorithmic performance beyond standard worst-case analysis, such as instance optimality and output sensitivity. Haeupler, Hladík, Rozhoň, Tarjan, and Tětek [FOCS’24] consider the notion of universal optimality, a refined complexity measure that accounts for both the graph topology and the edge weights. For a fixed graph topology, the universal running time of a weighted graph algorithm is defined as its worst-case running time over all possible edge weightings of G. An algorithm is universally optimal if no other algorithm achieves a better asymptotic universal running time on any particular graph topology. Haeupler, Hladík, Rozhoň, Tarjan, and Tětek show that Dijkstra’s algorithm can be made universally optimal by replacing the heap with a custom data structure. Their approach builds on Iacono’s [SWAT’00] working-set bound ϕ(x). This is a technical definition that, intuitively, for a heap element x, counts the maximum number of simultaneously-present elements y that were pushed onto the heap whilst x was in the heap. They design a new heap data structure that can pop an element x in O(1 + log ϕ(x)) time. They show that Dijkstra’s algorithm with their heap data structure is universally optimal. In this work, we revisit their result. We use a simpler heap property that we will call timestamp optimality, where the cost of popping an element x is logarithmic in the number of elements inserted between pushing and popping x. We show that timestamp optimal heaps are not only easier to define but also easier to implement. Using these time stamps, we provide a significantly simpler proof that Dijkstra’s algorithm, with the right kind of heap, is universally optimal
Relational Deskilling in the Digitalization of Care Work:Older Adult Volunteering in a Danish NGO
Get PDFDigitalization initiatives often assume universal benefits while overlooking their impact on established collaborative work practices. Through a case study of digitalization at a Danish NGO - drawing on interviews with 6 volunteers, observations of two implementation workshops,and discussions with project coordinators - we examine its effects on older volunteers, a demographic that constitutes 39% of Denmark's volunteer workforce. Our analysis suggests that digitalization: (1) creates tensions with underlying motivations for volunteering, (2) produces new forms of inefficiencies, (3) generates additional articulation work adapting to, or working around, the new processes, and (4) can be emotionally taxing to volunteers, generating feelings of inadequacy and reinforcing ageist perceptions. Our research contributes with: a) challenging ageist perceptions of digital competences with a socio-technical, rather than individual, understanding of digitalization as determining digital exclusion, b) a relational conceptualization of deskilling drawing on an ethics of care, and c) the suggestion that national strategies should resist idealized visions of technology and rather focus on preserving existing collaborative webs of care
Learned Cost Models for Query Optimization: From Batch to Streaming Systems.
No full textLearned cost models (LCMs) have recently gained traction as a promising alternative to traditional cost estimation techniques in data management, offering improved accuracy by capturing complex interactions between queries, data, and runtime behavior. While initially developed for batch systems, LCMs are now increasingly applied to stream processing as well, where real-time demands pose new challenges. This tutorial presents the first unified overview of LCMs across both batch and stream processing systems, examining their role as essential components in modern query optimizers. We explore key aspects of LCM design—including input representations and model architectures—and highlight how these models deal with query optimization tasks
On Dependencies in Knowledge Graph Construction
No full textKnowledge graph construction (KGC) requires numerous assets, such as shapes or mappings, to interact correctly.However, maintenance and assessment of the quality of the pipeline implementing the construction is difficult, assoftware engineering analyses and quality measures do not address the technologies used in KGC. In this paper,we propose a syntactic, easy to compute notion of dependencies between assets, and show its capability to assesschange propagation. Furthermore, we discuss potential to use it for coupling and impact estimation. We evaluateour approach using a prototypical implementation and a case study from the literature, where we find two bugswhere missing dependencies indicated an error due to miscommunication during change propagation betweenthe developers of two different assets
Movable optical sensor for automatic detection and monitoring of liquid-liquid interfaces
No full textLiquid-liquid extraction (LLE) is an essential operation in many laboratory experiments. However, most automatic LLE devices concentrate on detecting the liquid-liquid interface at one moment in the process, usually at separation, and pay little attention to the state of the liquids as they settle. In this paper, we present an LLE device with a moving optical sensor and light source that move along a vessel instead of the mixture moving relative to the sensor. Analyzing the patterns of light intensity with explainable automatic detection algorithms, the interface can be detected at different positions in the vessel with an error below 2 mm and monitored during the settling process. The device is tested using a mixture of clear oil and water and two extraction steps in a battery interface material synthesis process. Results show that the setup is able to detect interfaces at different positions along the vessel, even with changes in diameter. By monitoring the settling process, we also found that the biggest change in the signal detected occurs around the liquid-liquid interface position, and we also use this information to corroborate it. The recording of sensor measurements at different positions over time can be used to detect different properties of the liquids, which improves control over the process and could also alleviate reproducibility problems in areas of chemistry in which it is costly to repeat procedures
De-centering the (Traditional) user: Multistakeholder evaluation of recommender systems
No full textMultistakeholder recommender systems are those that account for the impacts and preferences of multiple groups of individuals, not just the end users receiving recommendations. Due to their complexity, these systems cannot be evaluated strictly by the overall utility of a single stakeholder, as is often the case of more mainstream recommender system applications. In this article, we focus our discussion on the challenges of multistakeholder evaluation of recommender systems. We bring attention to the different aspects involved—from the range of stakeholders involved (including but not limited to providers and consumers) to the values and specific goals of each relevant stakeholder. We discuss how to move from theoretical principles to practical implementation, providing specific use case examples. Finally, we outline open research directions for the RecSys community to explore. We aim to provide guidance to researchers and practitioners about incorporating these complex and domain-dependent issues of evaluation in the course of designing, developing, and researching applications with multistakeholder aspects