@misc{AlibabaieGhasemzadehMeinel2017,
  author    = {Alibabaie, Najmeh and Ghasemzadeh, Mohammad and Meinel, Christoph},
  title     = {A variant of genetic algorithm for non-homogeneous population},
  series = {International Conference Applied Mathematics, Computational Science and Systems Engineering 2016},
  volume    = {9},
  journal   = {International Conference Applied Mathematics, Computational Science and Systems Engineering 2016},
  publisher = {EDP Sciences},
  address   = {Les Ulis},
  issn      = {2271-2097},
  doi       = {10.1051/itmconf/20170902001},
  pages     = {8},
  year      = {2017},
  abstract  = {Selection of initial points, the number of clusters and finding proper clusters centers are still the main challenge in clustering processes. In this paper, we suggest genetic algorithm based method which searches several solution spaces simultaneously. The solution spaces are population groups consisting of elements with similar structure. Elements in a group have the same size, while elements in different groups are of different sizes. The proposed algorithm processes the population in groups of chromosomes with one gene, two genes to k genes. These genes hold corresponding information about the cluster centers. In the proposed method, the crossover and mutation operators can accept parents with different sizes; this can lead to versatility in population and information transfer among sub-populations. We implemented the proposed method and evaluated its performance against some random datasets and the Ruspini dataset as well. The experimental results show that the proposed method could effectively determine the appropriate number of clusters and recognize their centers. Overall this research implies that using heterogeneous population in the genetic algorithm can lead to better results.},
  language  = {en}
}
@misc{BartzYangBethgeetal.2019,
  author    = {Bartz, Christian and Yang, Haojin and Bethge, Joseph and Meinel, Christoph},
  title     = {LoANs},
  series = {Computer Vision - ACCV 2018 Workshops},
  volume    = {11367},
  journal   = {Computer Vision - ACCV 2018 Workshops},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-21074-8},
  issn      = {0302-9743},
  doi       = {10.1007/978-3-030-21074-8_29},
  pages     = {341 -- 356},
  year      = {2019},
  abstract  = {Recently, deep neural networks have achieved remarkable performance on the task of object detection and recognition. The reason for this success is mainly grounded in the availability of large scale, fully annotated datasets, but the creation of such a dataset is a complicated and costly task. In this paper, we propose a novel method for weakly supervised object detection that simplifies the process of gathering data for training an object detector. We train an ensemble of two models that work together in a student-teacher fashion. Our student (localizer) is a model that learns to localize an object, the teacher (assessor) assesses the quality of the localization and provides feedback to the student. The student uses this feedback to learn how to localize objects and is thus entirely supervised by the teacher, as we are using no labels for training the localizer. In our experiments, we show that our model is very robust to noise and reaches competitive performance compared to a state-of-the-art fully supervised approach. We also show the simplicity of creating a new dataset, based on a few videos (e.g. downloaded from YouTube) and artificially generated data.},
  language  = {en}
}
@misc{BjoerkHoelze2019,
  author    = {Bj{\"o}rk, Jennie and H{\"o}lze, Katharina},
  title     = {Editorial},
  series = {Creativity and innovation management},
  volume    = {28},
  journal   = {Creativity and innovation management},
  number    = {3},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0963-1690},
  doi       = {10.1111/caim.12336},
  pages     = {289 -- 290},
  year      = {2019},
  language  = {en}
}
@misc{FlorioTrappDoellner2019,
  author    = {Florio, Alessandro and Trapp, Matthias and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Semantic-driven Visualization Techniques for Interactive Exploration of 3D Indoor Models},
  series = {2019 23rd International Conference Information Visualisation (IV)},
  journal   = {2019 23rd International Conference Information Visualisation (IV)},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Los Alamitos},
  isbn      = {978-1-7281-2838-2},
  issn      = {2375-0138},
  doi       = {10.1109/IV.2019.00014},
  pages     = {25 -- 30},
  year      = {2019},
  abstract  = {The availability of detailed virtual 3D building models including representations of indoor elements, allows for a wide number of applications requiring effective exploration and navigation functionality. Depending on the application context, users should be enabled to focus on specific Objects-of-Interests (OOIs) or important building elements. This requires approaches to filtering building parts as well as techniques to visualize important building objects and their relations. For it, this paper explores the application and combination of interactive rendering techniques as well as their semanticallydriven configuration in the context of 3D indoor models.},
  language  = {en}
}
@misc{GawronChengMeinel2017,
  author    = {Gawron, Marian and Cheng, Feng and Meinel, Christoph},
  title     = {PVD: Passive Vulnerability Detection},
  series = {8th International Conference on Information and Communication Systems (ICICS)},
  journal   = {8th International Conference on Information and Communication Systems (ICICS)},
  publisher = {IEEE},
  address   = {New York},
  isbn      = {978-1-5090-4243-2},
  issn      = {2471-125X},
  doi       = {10.1109/IACS.2017.7921992},
  pages     = {322 -- 327},
  year      = {2017},
  abstract  = {The identification of vulnerabilities relies on detailed information about the target infrastructure. The gathering of the necessary information is a crucial step that requires an intensive scanning or mature expertise and knowledge about the system even though the information was already available in a different context. In this paper we propose a new method to detect vulnerabilities that reuses the existing information and eliminates the necessity of a comprehensive scan of the target system. Since our approach is able to identify vulnerabilities without the additional effort of a scan, we are able to increase the overall performance of the detection. Because of the reuse and the removal of the active testing procedures, our approach could be classified as a passive vulnerability detection. We will explain the approach and illustrate the additional possibility to increase the security awareness of users. Therefore, we applied the approach on an experimental setup and extracted security relevant information from web logs.},
  language  = {en}
}
@misc{GhahremaniGiese2019,
  author    = {Ghahremani, Sona and Giese, Holger},
  title     = {Performance evaluation for self-healing systems},
  series = {2019 IEEE 4th International Workshops on Foundations and Applications of Self* Systems (FAS*W)},
  journal   = {2019 IEEE 4th International Workshops on Foundations and Applications of Self* Systems (FAS*W)},
  publisher = {IEEE},
  address   = {New York},
  isbn      = {978-1-7281-2406-3},
  doi       = {10.1109/FAS-W.2019.00039},
  pages     = {116 -- 119},
  year      = {2019},
  abstract  = {Evaluating the performance of self-adaptive systems (SAS) is challenging due to their complexity and interaction with the often highly dynamic environment. In the context of self-healing systems (SHS), employing simulators has been shown to be the most dominant means for performance evaluation. Simulating a SHS also requires realistic fault injection scenarios. We study the state of the practice for evaluating the performance of SHS by means of a systematic literature review. We present the current practice and point out that a more thorough and careful treatment in evaluating the performance of SHS is required.},
  language  = {en}
}
@misc{Giese2017,
  author    = {Giese, Holger},
  title     = {Formal models and analysis for self-adaptive cyber-physical systems},
  series = {Lecture notes in computer science},
  volume    = {10231},
  journal   = {Lecture notes in computer science},
  editor    = {Kouchnarenko, Olga and Khosravi, Ramtin},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-57666-4},
  issn      = {0302-9743},
  doi       = {10.1007/978-3-319-57666-4_1},
  pages     = {3 -- 9},
  year      = {2017},
  abstract  = {In this extended abstract, we will analyze the current challenges for the envisioned Self-Adaptive CPS. In addition, we will outline our results to approach these challenges with SMARTSOS [10] a generic approach based on extensions of graph transformation systems employing open and adaptive collaborations and models at runtime for trustworthy self-adaptation, self-organization, and evolution of the individual systems and the system-of-systems level taking the independent development, operation, management, and evolution of these systems into account.},
  language  = {en}
}
@misc{Giese2019,
  author    = {Giese, Holger Burkhard},
  title     = {Software Engineering for Smart Cyber-Physical Systems},
  series = {Proceedings of the 12th Innovations on Software Engineering Conference},
  journal   = {Proceedings of the 12th Innovations on Software Engineering Conference},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-6215-3},
  doi       = {10.1145/3299771.3301650},
  pages     = {1},
  year      = {2019},
  abstract  = {Currently, a transformation of our technical world into a networked technical world where besides the embedded systems with their interaction with the physical world the interconnection of these nodes in the cyber world becomes a reality can be observed. In parallel nowadays there is a strong trend to employ artificial intelligence techniques and in particular machine learning to make software behave smart. Often cyber-physical systems must be self-adaptive at the level of the individual systems to operate as elements in open, dynamic, and deviating overall structures and to adapt to open and dynamic contexts while being developed, operated, evolved, and governed independently. In this presentation, we will first discuss the envisioned future scenarios for cyber-physical systems with an emphasis on the synergies networking can offer and then characterize which challenges for the design, production, and operation of these systems result. We will then discuss to what extent our current capabilities, in particular concerning software engineering match these challenges and where substantial improvements for the software engineering are crucial. In today's software engineering for embedded systems models are used to plan systems upfront to maximize envisioned properties on the one hand and minimize cost on the other hand. When applying the same ideas to software for smart cyber-physical systems, it soon turned out that for these systems often somehow more subtle links between the involved models and the requirements, users, and environment exist. Self-adaptation and runtime models have been advocated as concepts to covers the demands that result from these subtler links. Lately, both trends have been brought together more thoroughly by the notion of self-aware computing systems. We will review the underlying causes, discuss some our work in this direction, and outline related open challenges and potential for future approaches to software engineering for smart cyber-physical systems.},
  language  = {en}
}
@misc{HernandezDemirayArnrichetal.2019,
  author    = {Hernandez, Netzahualcoyotl and Demiray, Burcu and Arnrich, Bert and Favela, Jesus},
  title     = {An Exploratory Study to Detect Temporal Orientation Using Bluetooth's sensor},
  series = {PervasiveHealth'19: Proceedings of the 13th EAI International Conference on Pervasive Computing Technologies for Healthcare},
  journal   = {PervasiveHealth'19: Proceedings of the 13th EAI International Conference on Pervasive Computing Technologies for Healthcare},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-6126-2},
  issn      = {2153-1633},
  doi       = {10.1145/3329189.3329223},
  pages     = {292 -- 297},
  year      = {2019},
  abstract  = {Mobile sensing technology allows us to investigate human behaviour on a daily basis. In the study, we examined temporal orientation, which refers to the capacity of thinking or talking about personal events in the past and future. We utilise the mksense platform that allows us to use the experience-sampling method. Individual's thoughts and their relationship with smartphone's Bluetooth data is analysed to understand in which contexts people are influenced by social environments, such as the people they spend the most time with. As an exploratory study, we analyse social condition influence through a collection of Bluetooth data and survey information from participant's smartphones. Preliminary results show that people are likely to focus on past events when interacting with close-related people, and focus on future planning when interacting with strangers. Similarly, people experience present temporal orientation when accompanied by known people. We believe that these findings are linked to emotions since, in its most basic state, emotion is a state of physiological arousal combined with an appropriated cognition. In this contribution, we envision a smartphone application for automatically inferring human emotions based on user's temporal orientation by using Bluetooth sensors, we briefly elaborate on the influential factor of temporal orientation episodes and conclude with a discussion and lessons learned.},
  language  = {en}
}
@misc{HerzogHoenigSchroederPreikschatetal.2019,
  author    = {Herzog, Benedict and H{\"o}nig, Timo and Schr{\"o}der-Preikschat, Wolfgang and Plauth, Max and K{\"o}hler, Sven and Polze, Andreas},
  title     = {Bridging the Gap},
  series = {e-Energy '19: Proceedings of the Tenth ACM International Conference on Future Energy Systems},
  journal   = {e-Energy '19: Proceedings of the Tenth ACM International Conference on Future Energy Systems},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-6671-7},
  doi       = {10.1145/3307772.3330176},
  pages     = {428 -- 430},
  year      = {2019},
  abstract  = {The recent restructuring of the electricity grid (i.e., smart grid) introduces a number of challenges for today's large-scale computing systems. To operate reliable and efficient, computing systems must adhere not only to technical limits (i.e., thermal constraints) but they must also reduce operating costs, for example, by increasing their energy efficiency. Efforts to improve the energy efficiency, however, are often hampered by inflexible software components that hardly adapt to underlying hardware characteristics. In this paper, we propose an approach to bridge the gap between inflexible software and heterogeneous hardware architectures. Our proposal introduces adaptive software components that dynamically adapt to heterogeneous processing units (i.e., accelerators) during runtime to improve the energy efficiency of computing systems.},
  language  = {en}
}
@misc{HesseMatthiesSinzigetal.2019,
  author    = {Hesse, G{\"u}nter and Matthies, Christoph and Sinzig, Werner and Uflacker, Matthias},
  title     = {Adding Value by Combining Business and Sensor Data},
  series = {Database Systems for Advanced Applications},
  volume    = {11448},
  journal   = {Database Systems for Advanced Applications},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-18590-9},
  issn      = {0302-9743},
  doi       = {10.1007/978-3-030-18590-9_80},
  pages     = {528 -- 532},
  year      = {2019},
  abstract  = {Industry 4.0 and the Internet of Things are recent developments that have lead to the creation of new kinds of manufacturing data. Linking this new kind of sensor data to traditional business information is crucial for enterprises to take advantage of the data's full potential. In this paper, we present a demo which allows experiencing this data integration, both vertically between technical and business contexts and horizontally along the value chain. The tool simulates a manufacturing company, continuously producing both business and sensor data, and supports issuing ad-hoc queries that answer specific questions related to the business. In order to adapt to different environments, users can configure sensor characteristics to their needs.},
  language  = {en}
}
@misc{LimbergerScheibelTrappetal.2017,
  author    = {Limberger, Daniel and Scheibel, Willy and Trapp, Matthias and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Mixed-projection treemaps},
  series = {21st International Conference Information Visualisation (IV)},
  journal   = {21st International Conference Information Visualisation (IV)},
  publisher = {Institute of Electrical and Electronics Engineers},
  address   = {Los Alamitos},
  isbn      = {978-1-5386-0831-9},
  issn      = {2375-0138},
  doi       = {10.1109/iV.2017.67},
  pages     = {164 -- 169},
  year      = {2017},
  abstract  = {This paper presents a novel technique for combining 2D and 2.5D treemaps using multi-perspective views to leverage the advantages of both treemap types. It enables a new form of overview+detail visualization for tree-structured data and contributes new concepts for real-time rendering of and interaction with treemaps. The technique operates by tilting the graphical elements representing inner nodes using affine transformations and animated state transitions. We explain how to mix orthogonal and perspective projections within a single treemap. Finally, we show application examples that benefit from the reduced interaction overhead.},
  language  = {en}
}
@misc{LorenzKiekhebenSchnor2017,
  author    = {Lorenz, Claas and Kiekheben, Sebastian and Schnor, Bettina},
  title     = {FaVe: Modeling IPv6 firewalls for fast formal verification},
  series = {International Conference on Networked Systems (NetSys) 2017},
  journal   = {International Conference on Networked Systems (NetSys) 2017},
  publisher = {IEEE},
  address   = {New York},
  doi       = {10.1109/NetSys.2017.7903956},
  pages     = {8},
  year      = {2017},
  abstract  = {As virtualization drives the automation of networking, the validation of security properties becomes more and more challenging eventually ruling out manual inspections. While formal verification in Software Defined Networks is provided by comprehensive tools with high speed reverification capabilities like NetPlumber for instance, the presence of middlebox functionality like firewalls is not considered. Also, they lack the ability to handle dynamic protocol elements like IPv6 extension header chains. In this work, we provide suitable modeling abstractions to enable both - the inclusion of firewalls and dynamic protocol elements. We exemplarily model the Linux ip6tables/netfilter packet filter and also provide abstractions for an application layer gateway. Finally, we present a prototype of our formal verification system FaVe.},
  language  = {en}
}
@misc{MalchowRenzBaueretal.2017,
  author    = {Malchow, Martin and Renz, Jan and Bauer, Matthias and Meinel, Christoph},
  title     = {Embedded smart home},
  series = {11th Annual IEEE International Systems Conference (SysCon)},
  journal   = {11th Annual IEEE International Systems Conference (SysCon)},
  publisher = {IEEE},
  address   = {New York},
  isbn      = {978-1-5090-4623-2},
  issn      = {1944-7620},
  doi       = {10.1109/SYSCON.2017.7934728},
  pages     = {195 -- 200},
  year      = {2017},
  abstract  = {The popularity of MOOCs has increased considerably in the last years. A typical MOOC course consists of video content, self tests after a video and homework, which is normally in multiple choice format. After solving this homeworks for every week of a MOOC, the final exam certificate can be issued when the student has reached a sufficient score. There are also some attempts to include practical tasks, such as programming, in MOOCs for grading. Nevertheless, until now there is no known possibility to teach embedded system programming in a MOOC course where the programming can be done in a remote lab and where grading of the tasks is additionally possible. This embedded programming includes communication over GPIO pins to control LEDs and measure sensor values. We started a MOOC course called "Embedded Smart Home" as a pilot to prove the concept to teach real hardware programming in a MOOC environment under real life MOOC conditions with over 6000 students. Furthermore, also students with real hardware have the possibility to program on their own real hardware and grade their results in the MOOC course. Finally, we evaluate our approach and analyze the student acceptance of this approach to offer a course on embedded programming. We also analyze the hardware usage and working time of students solving tasks to find out if real hardware programming is an advantage and motivating achievement to support students learning success.},
  language  = {en}
}
@misc{MarweckiWilsonOfeketal.2019,
  author    = {Marwecki, Sebastian and Wilson, Andrew D. and Ofek, Eyal and Franco, Mar Gonzalez and Holz, Christian},
  title     = {Mise-Unseen},
  series = {UIST '19: Proceedings of the 32nd Annual ACM Symposium on User Interface Software and Technology},
  journal   = {UIST '19: Proceedings of the 32nd Annual ACM Symposium on User Interface Software and Technology},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-6816-2},
  doi       = {10.1145/3332165.3347919},
  pages     = {777 -- 789},
  year      = {2019},
  abstract  = {Creating or arranging objects at runtime is needed in many virtual reality applications, but such changes are noticed when they occur inside the user's field of view. We present Mise-Unseen, a software system that applies such scene changes covertly inside the user's field of view. Mise-Unseen leverages gaze tracking to create models of user attention, intention, and spatial memory to determine if and when to inject a change. We present seven applications of Mise-Unseen to unnoticeably modify the scene within view (i) to hide that task difficulty is adapted to the user, (ii) to adapt the experience to the user's preferences, (iii) to time the use of low fidelity effects, (iv) to detect user choice for passive haptics even when lacking physical props, (v) to sustain physical locomotion despite a lack of physical space, (vi) to reduce motion sickness during virtual locomotion, and (vii) to verify user understanding during story progression. We evaluated Mise-Unseen and our applications in a user study with 15 participants and find that while gaze data indeed supports obfuscating changes inside the field of view, a change is rendered unnoticeably by using gaze in combination with common masking techniques.},
  language  = {en}
}
@misc{PerscheidUflacker2019,
  author    = {Perscheid, Cindy and Uflacker, Matthias},
  title     = {Integrating Biological Context into the Analysis of Gene Expression Data},
  series = {Distributed Computing and Artificial Intelligence, Special Sessions, 15th International Conference},
  volume    = {801},
  journal   = {Distributed Computing and Artificial Intelligence, Special Sessions, 15th International Conference},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-99608-0},
  issn      = {2194-5357},
  doi       = {10.1007/978-3-319-99608-0_41},
  pages     = {339 -- 343},
  year      = {2019},
  abstract  = {High-throughput RNA sequencing produces large gene expression datasets whose analysis leads to a better understanding of diseases like cancer. The nature of RNA-Seq data poses challenges to its analysis in terms of its high dimensionality, noise, and complexity of the underlying biological processes. Researchers apply traditional machine learning approaches, e. g. hierarchical clustering, to analyze this data. Until it comes to validation of the results, the analysis is based on the provided data only and completely misses the biological context. However, gene expression data follows particular patterns - the underlying biological processes. In our research, we aim to integrate the available biological knowledge earlier in the analysis process. We want to adapt state-of-the-art data mining algorithms to consider the biological context in their computations and deliver meaningful results for researchers.},
  language  = {en}
}
@misc{PlauthSterzEberhardtetal.2017,
  author    = {Plauth, Max and Sterz, Christoph and Eberhardt, Felix and Feinbube, Frank and Polze, Andreas},
  title     = {Assessing NUMA performance based on hardware event counters},
  series = {IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW)},
  journal   = {IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW)},
  publisher = {Institute of Electrical and Electronics Engineers},
  address   = {New York},
  isbn      = {978-0-7695-6149-3},
  issn      = {2164-7062},
  doi       = {10.1109/IPDPSW.2017.51},
  pages     = {904 -- 913},
  year      = {2017},
  abstract  = {Cost models play an important role for the efficient implementation of software systems. These models can be embedded in operating systems and execution environments to optimize execution at run time. Even though non-uniform memory access (NUMA) architectures are dominating today's server landscape, there is still a lack of parallel cost models that represent NUMA system sufficiently. Therefore, the existing NUMA models are analyzed, and a two-step performance assessment strategy is proposed that incorporates low-level hardware counters as performance indicators. To support the two-step strategy, multiple tools are developed, all accumulating and enriching specific hardware event counter information, to explore, measure, and visualize these low-overhead performance indicators. The tools are showcased and discussed alongside specific experiments in the realm of performance assessment.},
  language  = {en}
}
@misc{PodlesnyKayemMeinel2019,
  author    = {Podlesny, Nikolai Jannik and Kayem, Anne V. D. M. and Meinel, Christoph},
  title     = {Attribute Compartmentation and Greedy UCC Discovery for High-Dimensional Data Anonymisation},
  series = {Proceedings of the Ninth ACM Conference on Data and Application Security and Privacy},
  journal   = {Proceedings of the Ninth ACM Conference on Data and Application Security and Privacy},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-6099-9},
  doi       = {10.1145/3292006.3300019},
  pages     = {109 -- 119},
  year      = {2019},
  abstract  = {High-dimensional data is particularly useful for data analytics research. In the healthcare domain, for instance, high-dimensional data analytics has been used successfully for drug discovery. Yet, in order to adhere to privacy legislation, data analytics service providers must guarantee anonymity for data owners. In the context of high-dimensional data, ensuring privacy is challenging because increased data dimensionality must be matched by an exponential growth in the size of the data to avoid sparse datasets. Syntactically, anonymising sparse datasets with methods that rely of statistical significance, makes obtaining sound and reliable results, a challenge. As such, strong privacy is only achievable at the cost of high information loss, rendering the data unusable for data analytics. In this paper, we make two contributions to addressing this problem from both the privacy and information loss perspectives. First, we show that by identifying dependencies between attribute subsets we can eliminate privacy violating attributes from the anonymised dataset. Second, to minimise information loss, we employ a greedy search algorithm to determine and eliminate maximal partial unique attribute combinations. Thus, one only needs to find the minimal set of identifying attributes to prevent re-identification. Experiments on a health cloud based on the SAP HANA platform using a semi-synthetic medical history dataset comprised of 109 attributes, demonstrate the effectiveness of our approach.},
  language  = {en}
}
@misc{RoumenShigeyamaRudolphetal.2019,
  author    = {Roumen, Thijs and Shigeyama, Jotaro and Rudolph, Julius Cosmo Romeo and Grzelka, Felix and Baudisch, Patrick},
  title     = {SpringFit},
  series = {User Interface Software and Technology},
  journal   = {User Interface Software and Technology},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-6816-2},
  doi       = {10.1145/3332165.3347930},
  pages     = {727 -- 738},
  year      = {2019},
  abstract  = {Joints are crucial to laser cutting as they allow making three-dimensional objects; mounts are crucial because they allow embedding technical components, such as motors. Unfortunately, mounts and joints tend to fail when trying to fabricate a model on a different laser cutter or from a different material. The reason for this lies in the way mounts and joints hold objects in place, which is by forcing them into slightly smaller openings. Such "press fit" mechanisms unfortunately are susceptible to the small changes in diameter that occur when switching to a machine that removes more or less material ("kerf"), as well as to changes in stiffness, as they occur when switching to a different material. We present a software tool called springFit that resolves this problem by replacing the problematic press fit-based mounts and joints with what we call cantilever-based mounts and joints. A cantilever spring is simply a long thin piece of material that pushes against the object to be held. Unlike press fits, cantilever springs are robust against variations in kerf and material; they can even handle very high variations, simply by using longer springs. SpringFit converts models in the form of 2D cutting plans by replacing all contained mounts, notch joints, finger joints, and t-joints. In our technical evaluation, we used springFit to convert 14 models downloaded from the web.},
  language  = {en}
}
@misc{SchneiderShigeyamaKovacsetal.2018,
  author    = {Schneider, Oliver and Shigeyama, Jotaro and Kovacs, Robert and Roumen, Thijs Jan and Marwecki, Sebastian and B{\"o}ckhoff, Nico and Gl{\"o}ckner, Daniel Amadeus Johannes and Bounama, Jonas and Baudisch, Patrick},
  title     = {DualPanto},
  series = {UIST '18: Proceedings of the 31st Annual ACM Symposium on User Interface Software and Technology},
  journal   = {UIST '18: Proceedings of the 31st Annual ACM Symposium on User Interface Software and Technology},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-5948-1},
  doi       = {10.1145/3242587.3242604},
  pages     = {877 -- 887},
  year      = {2018},
  abstract  = {We present a new haptic device that enables blind users to continuously track the absolute position of moving objects in spatial virtual environments, as is the case in sports or shooter games. Users interact with DualPanto by operating the me handle with one hand and by holding on to the it handle with the other hand. Each handle is connected to a pantograph haptic input/output device. The key feature is that the two handles are spatially registered with respect to each other. When guiding their avatar through a virtual world using the me handle, spatial registration enables users to track moving objects by having the device guide the output hand. This allows blind players of a 1-on-1 soccer game to race for the ball or evade an opponent; it allows blind players of a shooter game to aim at an opponent and dodge shots. In our user study, blind participants reported very high enjoyment when using the device to play (6.5/7).},
  language  = {en}
}
@misc{SeidelKrentzMeinel2019,
  author    = {Seidel, Felix and Krentz, Konrad-Felix and Meinel, Christoph},
  title     = {Deep En-Route Filtering of Constrained Application Protocol (CoAP) Messages on 6LoWPAN Border Routers},
  series = {2019 IEEE 5th World Forum on Internet of Things (WF-IoT)},
  journal   = {2019 IEEE 5th World Forum on Internet of Things (WF-IoT)},
  publisher = {Institute of Electrical and Electronics Engineers},
  address   = {New York},
  isbn      = {978-1-5386-4980-0},
  doi       = {10.1109/WF-IoT.2019.8767262},
  pages     = {201 -- 206},
  year      = {2019},
  abstract  = {Devices on the Internet of Things (IoT) are usually battery-powered and have limited resources. Hence, energy-efficient and lightweight protocols were designed for IoT devices, such as the popular Constrained Application Protocol (CoAP). Yet, CoAP itself does not include any defenses against denial-of-sleep attacks, which are attacks that aim at depriving victim devices of entering low-power sleep modes. For example, a denial-of-sleep attack against an IoT device that runs a CoAP server is to send plenty of CoAP messages to it, thereby forcing the IoT device to expend energy for receiving and processing these CoAP messages. All current security solutions for CoAP, namely Datagram Transport Layer Security (DTLS), IPsec, and OSCORE, fail to prevent such attacks. To fill this gap, Seitz et al. proposed a method for filtering out inauthentic and replayed CoAP messages "en-route" on 6LoWPAN border routers. In this paper, we expand on Seitz et al.'s proposal in two ways. First, we revise Seitz et al.'s software architecture so that 6LoWPAN border routers can not only check the authenticity and freshness of CoAP messages, but can also perform a wide range of further checks. Second, we propose a couple of such further checks, which, as compared to Seitz et al.'s original checks, more reliably protect IoT devices that run CoAP servers from remote denial-of-sleep attacks, as well as from remote exploits. We prototyped our solution and successfully tested its compatibility with Contiki-NG's CoAP implementation.},
  language  = {en}
}
@misc{SerthPodlesnyBornsteinetal.2017,
  author    = {Serth, Sebastian and Podlesny, Nikolai and Bornstein, Marvin and Lindemann, Jan and Latt, Johanna and Selke, Jan and Schlosser, Rainer and Boissier, Martin and Uflacker, Matthias},
  title     = {An interactive platform to simulate dynamic pricing competition on online marketplaces},
  series = {2017 IEEE 21st International Enterprise Distributed Object Computing Conference (EDOC)},
  journal   = {2017 IEEE 21st International Enterprise Distributed Object Computing Conference (EDOC)},
  publisher = {Institute of Electrical and Electronics Engineers},
  address   = {New York},
  isbn      = {978-1-5090-3045-3},
  issn      = {2325-6354},
  doi       = {10.1109/EDOC.2017.17},
  pages     = {61 -- 66},
  year      = {2017},
  abstract  = {E-commerce marketplaces are highly dynamic with constant competition. While this competition is challenging for many merchants, it also provides plenty of opportunities, e.g., by allowing them to automatically adjust prices in order to react to changing market situations. For practitioners however, testing automated pricing strategies is time-consuming and potentially hazardously when done in production. Researchers, on the other side, struggle to study how pricing strategies interact under heavy competition. As a consequence, we built an open continuous time framework to simulate dynamic pricing competition called Price Wars. The microservice-based architecture provides a scalable platform for large competitions with dozens of merchants and a large random stream of consumers. Our platform stores each event in a distributed log. This allows to provide different performance measures enabling users to compare profit and revenue of various repricing strategies in real-time. For researchers, price trajectories are shown which ease evaluating mutual price reactions of competing strategies. Furthermore, merchants can access historical marketplace data and apply machine learning. By providing a set of customizable, artificial merchants, users can easily simulate both simple rule-based strategies as well as sophisticated data-driven strategies using demand learning to optimize their pricing strategies.},
  language  = {en}
}
@misc{SianiparWillemsMeinel2019,
  author    = {Sianipar, Johannes Harungguan and Willems, Christian and Meinel, Christoph},
  title     = {Virtual machine integrity verification in Crowd-Resourcing Virtual Laboratory},
  series = {2018 IEEE 11th Conference on Service-Oriented Computing and Applications (SOCA)},
  journal   = {2018 IEEE 11th Conference on Service-Oriented Computing and Applications (SOCA)},
  publisher = {IEEE},
  address   = {New York},
  isbn      = {978-1-5386-9133-5},
  issn      = {2163-2871},
  doi       = {10.1109/SOCA.2018.00032},
  pages     = {169 -- 176},
  year      = {2019},
  abstract  = {In cloud computing, users are able to use their own operating system (OS) image to run a virtual machine (VM) on a remote host. The virtual machine OS is started by the user using some interfaces provided by a cloud provider in public or private cloud. In peer to peer cloud, the VM is started by the host admin. After the VM is running, the user could get a remote access to the VM to install, configure, and run services. For the security reasons, the user needs to verify the integrity of the running VM, because a malicious host admin could modify the image or even replace the image with a similar image, to be able to get sensitive data from the VM. We propose an approach to verify the integrity of a running VM on a remote host, without using any specific hardware such as Trusted Platform Module (TPM). Our approach is implemented on a Linux platform where the kernel files (vmlinuz and initrd) could be replaced with new files, while the VM is running. kexec is used to reboot the VM with the new kernel files. The new kernel has secret codes that will be used to verify whether the VM was started using the new kernel files. The new kernel is used to further measuring the integrity of the running VM.},
  language  = {en}
}
@misc{StaubitzWilkinsHagedornetal.2017,
  author    = {Staubitz, Thomas and Wilkins, Christian and Hagedorn, Christiane and Meinel, Christoph},
  title     = {The Gamification of a MOOC Platform},
  series = {Proceedings of 2017 IEEE Global Engineering Education Conference (EDUCON)},
  journal   = {Proceedings of 2017 IEEE Global Engineering Education Conference (EDUCON)},
  publisher = {IEEE},
  address   = {New York},
  isbn      = {978-1-5090-5467-1},
  issn      = {2165-9567},
  doi       = {10.1109/EDUCON.2017.7942952},
  pages     = {883 -- 892},
  year      = {2017},
  abstract  = {Massive Open Online Courses (MOOCs) have left their mark on the face of education during the recent years. At the Hasso Plattner Institute (HPI) in Potsdam, Germany, we are actively developing a MOOC platform, which provides our research with a plethora of e-learning topics, such as learning analytics, automated assessment, peer assessment, team-work, online proctoring, and gamification. We run several instances of this platform. On openHPI, we provide our own courses from within the HPI context. Further instances are openSAP, openWHO, and mooc.HOUSE, which is the smallest of these platforms, targeting customers with a less extensive course portfolio. In 2013, we started to work on the gamification of our platform. By now, we have implemented about two thirds of the features that we initially have evaluated as useful for our purposes. About a year ago we activated the implemented gamification features on mooc.HOUSE. Before activating the features on openHPI as well, we examined, and re-evaluated our initial considerations based on the data we collected so far and the changes in other contexts of our platforms.},
  language  = {en}
}
@misc{StojanovicTrappRichteretal.2018,
  author    = {Stojanovic, Vladeta and Trapp, Matthias and Richter, Rico and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {A service-oriented approach for classifying 3D points clouds by example of office furniture classification},
  series = {Web3D 2018: Proceedings of the 23rd International ACM Conference on 3D Web Technology},
  journal   = {Web3D 2018: Proceedings of the 23rd International ACM Conference on 3D Web Technology},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  isbn      = {978-1-4503-5800-2},
  doi       = {10.1145/3208806.3208810},
  pages     = {1 -- 9},
  year      = {2018},
  abstract  = {The rapid digitalization of the Facility Management (FM) sector has increased the demand for mobile, interactive analytics approaches concerning the operational state of a building. These approaches provide the key to increasing stakeholder engagement associated with Operation and Maintenance (O\&M) procedures of living and working areas, buildings, and other built environment spaces. We present a generic and fast approach to process and analyze given 3D point clouds of typical indoor office spaces to create corresponding up-to-date approximations of classified segments and object-based 3D models that can be used to analyze, record and highlight changes of spatial configurations. The approach is based on machine-learning methods used to classify the scanned 3D point cloud data using 2D images. This approach can be used to primarily track changes of objects over time for comparison, allowing for routine classification, and presentation of results used for decision making. We specifically focus on classification, segmentation, and reconstruction of multiple different object types in a 3D point-cloud scene. We present our current research and describe the implementation of these technologies as a web-based application using a services-oriented methodology.},
  language  = {en}
}
@misc{SukmanaTorkuraGraupneretal.2019,
  author    = {Sukmana, Muhammad Ihsan Haikal and Torkura, Kennedy A. and Graupner, Hendrik and Cheng, Feng and Meinel, Christoph},
  title     = {Unified Cloud Access Control Model for Cloud Storage Broker},
  series = {33rd International Conference on Information Networking (ICOIN 2019)},
  journal   = {33rd International Conference on Information Networking (ICOIN 2019)},
  publisher = {IEEE},
  address   = {Los Alamitos},
  isbn      = {978-1-5386-8350-7},
  issn      = {1976-7684},
  doi       = {10.1109/ICOIN.2019.8717982},
  pages     = {60 -- 65},
  year      = {2019},
  abstract  = {Cloud Storage Broker (CSB) provides value-added cloud storage service for enterprise usage by leveraging multi-cloud storage architecture. However, it raises several challenges for managing resources and its access control in multiple Cloud Service Providers (CSPs) for authorized CSB stakeholders. In this paper we propose unified cloud access control model that provides the abstraction of CSP's services for centralized and automated cloud resource and access control management in multiple CSPs. Our proposal offers role-based access control for CSB stakeholders to access cloud resources by assigning necessary privileges and access control list for cloud resources and CSB stakeholders, respectively, following privilege separation concept and least privilege principle. We implement our unified model in a CSB system called CloudRAID for Business (CfB) with the evaluation result shows it provides system-and-cloud level security service for cfB and centralized resource and access control management in multiple CSPs.},
  language  = {en}
}
@misc{TorkuraSukmanaChengetal.2017,
  author    = {Torkura, Kennedy A. and Sukmana, Muhammad Ihsan Haikal and Cheng, Feng and Meinel, Christoph},
  title     = {Leveraging cloud native design patterns for security-as-a-service applications},
  series = {IEEE International Conference on Smart Cloud (SmartCloud)},
  journal   = {IEEE International Conference on Smart Cloud (SmartCloud)},
  publisher = {Institute of Electrical and Electronics Engineers},
  address   = {New York},
  isbn      = {978-1-5386-3684-8},
  doi       = {10.1109/SmartCloud.2017.21},
  pages     = {90 -- 97},
  year      = {2017},
  abstract  = {This paper discusses a new approach for designing and deploying Security-as-a-Service (SecaaS) applications using cloud native design patterns. Current SecaaS approaches do not efficiently handle the increasing threats to computer systems and applications. For example, requests for security assessments drastically increase after a high-risk security vulnerability is disclosed. In such scenarios, SecaaS applications are unable to dynamically scale to serve requests. A root cause of this challenge is employment of architectures not specifically fitted to cloud environments. Cloud native design patterns resolve this challenge by enabling certain properties e.g. massive scalability and resiliency via the combination of microservice patterns and cloud-focused design patterns. However adopting these patterns is a complex process, during which several security issues are introduced. In this work, we investigate these security issues, we redesign and deploy a monolithic SecaaS application using cloud native design patterns while considering appropriate, layered security counter-measures i.e. at the application and cloud networking layer. Our prototype implementation out-performs traditional, monolithic applications with an average Scanner Time of 6 minutes, without compromising security. Our approach can be employed for designing secure, scalable and performant SecaaS applications that effectively handle unexpected increase in security assessment requests.},
  language  = {en}
}
@misc{TrappDoellner2019,
  author    = {Trapp, Matthias and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Interactive Close-Up Rendering for Detail plus Overview Visualization of 3D Digital Terrain Models},
  series = {2019 23rd International Conference Information Visualisation (IV)},
  journal   = {2019 23rd International Conference Information Visualisation (IV)},
  editor    = {Banissi, E Ursyn},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Los Alamitos},
  isbn      = {978-1-7281-2838-2},
  issn      = {2375-0138},
  doi       = {10.1109/IV.2019.00053},
  pages     = {275 -- 280},
  year      = {2019},
  abstract  = {This paper presents an interactive rendering technique for detail+overview visualization of 3D digital terrain models using interactive close-ups. A close-up is an alternative presentation of input data varying with respect to geometrical scale, mapping, appearance, as well as Level-of-Detail (LOD) and Level-of-Abstraction (LOA) used. The presented 3D close-up approach enables in-situ comparison of multiple Regionof-Interests (ROIs) simultaneously. We describe a GPU-based rendering technique for the image-synthesis of multiple close-ups in real-time.},
  language  = {en}
}
@misc{TrappDoellner2019,
  author    = {Trapp, Matthias and D{\"o}llner, J{\"u}rgen Roland Friedrich},
  title     = {Real-time Screen-space Geometry Draping for 3D Digital Terrain Models},
  series = {2019 23rd International Conference Information Visualisation (IV)},
  journal   = {2019 23rd International Conference Information Visualisation (IV)},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Los Alamitos},
  isbn      = {978-1-7281-2838-2},
  issn      = {2375-0138},
  doi       = {10.1109/IV.2019.00054},
  pages     = {281 -- 286},
  year      = {2019},
  abstract  = {A fundamental task in 3D geovisualization and GIS applications is the visualization of vector data that can represent features such as transportation networks or land use coverage. Mapping or draping vector data represented by geometric primitives (e.g., polylines or polygons) to 3D digital elevation or 3D digital terrain models is a challenging task. We present an interactive GPU-based approach that performs geometry-based draping of vector data on per-frame basis using an image-based representation of a 3D digital elevation or terrain model only.},
  language  = {en}
}