Michael Vatareck

• Dr.
• Software Engineer at Google Inc.

Elastic distributed stream processing systems are able to dynamically adapt to changes in the workload. Often, these systems react to the rate of incoming data, or to the level of resource utilization, by scaling up or down. The goal is to optimize the system's resource usage, thereby reducing its operational cost. However, such scaling operations...

Traditionally, research in Business Process Management has put a strong focus on centralized and intra-organizational processes. However, today's business processes are increasingly distributed, deviating from a centralized layout, and therefore calling for novel methodologies of detecting and responding to unforeseen events, such as errors occurri...

The Internet of Things (IoT) leads to an ever-growing presence of ubiquitous networked computing devices in public, business, and private spaces. These devices do not simply act as sensors, but feature computational, storage, and networking resources. Being located at the edge of the network, these resources can be exploited to execute IoT applicat...

A major challenge in Cloud computing is resource provisioning for computational tasks. Not surprisingly, previous work has established a number of solutions to provide Cloud resources in an efficient manner. However, in order to realize a holistic resource provisioning model, a prediction of the future resource consumption of upcoming computational...

The usage of Web or Cloud-based applications on mobile devices suffers from varying link quality, which causes user-perceivable delays and therefore reduces the Quality of Experience (QoE). On the other hand, mobile devices are increasingly feature-rich, allowing to make usage of context data in order to predict network quality based on the user's...

First responders can benefit greatly from the newest progress in technological means, such as the application of unmanned aircraft systems (UAS), to improve the assessment of a disaster situation and reduce the risk of future casualties caused by large-scale natural disasters. The application of UAS in search and rescue missions has proved to be an...

In recent years, manifold blockchain protocols have been proposed by researchers and industrial companies alike. This has led to a very heterogeneous blockchain landscape. Accordingly, it would be desirable if blockchains could interact with each other. However, current blockchain technologies offer only limited support for interoperability, thus p...

As data collected and provided by Internet of Things (IoT) devices power an ever-growing number of applications and services, it is crucial that this data can be trusted. Data provenance solutions combined with blockchain technology are one way to make data more trustworthy by providing tamper-proof information about the origin and history of data...

Modern distributed systems, such as cloud computing infrastructures or data stream processing engines, perform resource provisioning tasks such as resource allocation, task scheduling, or scaling. This decision-making substantially influences the systems' performance, and therefore, the manner of reaching these decisions is crucial to the systems'...

As more and more applications and services depend on data collected and provided by Internet of Things (IoT) devices, it is of importance that such data can be trusted. Data provenance solutions together with blockchain technology are one way to make data more trustworthy. However, current solutions do not address the heterogeneous nature of IoT ap...

In recent years, distributed ledger technologies like blockchains have gained much popularity both within industry and research. Today, blockchains do not only act as the underlying technology for cryptocurrencies like Bitcoin, but have also been identified as a potentially disruptive technology in many different fields, e.g., supply chain tracking...

In recent years, distributed ledger technologies like blockchains have gained much popularity both within industry and research. Today, blockchains do not only act as the underlying technology for cryptocurrencies like Bitcoin, but have also been identified as a potentially disruptive technology in many different fields, e.g., supply chain tracking...

Current blockchain technologies provide very limited interoperability. Restrictions with regard to asset transfers and data exchange between different blockchains reduce the usability and comfort of users, and hinder novel developments within the blockchain space. As a first step towards blockchain interoperability, we propose the DeXTT cross-block...

Current blockchain technologies provide very limited interoperability. Restrictions with regards to asset transfers and data exchange between different blockchains reduce usability and comfort for users, and hinder novel developments within the blockchain space. As a first step towards cross-blockchain interoperability, we propose the DeXTT cross-b...

As more and more applications and services depend on data collected by Internet of Things (IoT) devices, it is of utmost importance that such data can be trusted. While data provenance solutions together with blockchain technology are one way to make data more trustworthy, current solutions do not address the heterogeneous nature of IoT application...

The suitability of a particular blockchain for a given use case depends mainly on the blockchain's functional and non-functional properties. Such properties may vary over time, and thus, a selected blockchain may become unsuitable for a given use case. This uncertainty may hinder the widespread adoption of blockchain technologies in general. To mit...

Interoperability between blockchains remains an open problem, with current interoperability approaches providing very limited means of cross-blockchain interaction, mostly in the form of atomic swaps. More general means of blockchain in-teroperability such as cross-blockchain data exchange, including cross-blockchain token transfer would contribute...

Edge and fog computing applications typically focus on outsourcing computations from static or mobile end user devices towards compute nodes in proximity. However, such applications do not fully exploit the benefits of the edge because the resources of neighboring end user devices are not considered as potential compute nodes. For this reason, we p...

Interoperability between blockchains remains an open problem, with current approaches providing very limited means of cross-blockchain interaction, mostly in the form of atomic swaps. However, very little means of cross-blockchain data exchange, including cross-blockchain token transfers, are found in literature. To address this issue, within the T...

Technologies enabling interoperability across blockchains have recently gained much popularity in science and industry. Cross-blockchain asset transfers are one particular use case which has been proposed to foster such interoperability. In previous work, we have presented the concept of claim-first transactions as a method of transferring assets f...

In software testing, verification of a system's dynamic properties such as auto-scaling behavior can be vital for a project's success. However, testing such properties can be difficult when parts of the system are not implemented yet, mocked or simply not available, as those parts might have a great impact on the system's runtime behavior. To addre...

In smart system scenarios, such as the Internet of Things (IoT), managing data traffic remains a crucial challenge, with high data volumes and low data transmission rates significantly hindering user experience. In this light, a promising technique is data prefetching, which involves the fetching of data on specific devices before it is required by...

In cloud computing, detecting violations of Service Level Agreements (SLAs) is possible by measuring certain metrics, which can be done by both the provider and the consumer of a service. However, both parties have contradicting interests with regards to these measurements, which makes it difficult to reach consensus about whether SLA violations ha...

Cryptocurrencies share a broad overall purpose, enabling distributed, decentralized and trustless transfers of value. Nevertheless, the various blockchains upon which each cryptocurrency is implemented remain, for the most part, unconnected. While approaches for atomic swaps (the secure exchange of tokens on one chain for another) are emerging, the...

Blockchains, the fundamental technology upon which cryptocurrencies are implemented, have gained considerable interest in finance, economics, and research. Nevertheless, the numerous blockchains in existence remain mostly unconnected, with no possibilities for interoperability. While approaches for atomic swaps (the atomic exchange of value on two...

Traditionally, research in Business Process Management has put a strong focus on centralized and intra-organizational processes. However, today's business processes are increasingly distributed, deviating from a centralized layout, and therefore calling for novel methodologies of detecting and responding to unforeseen events, such as errors occurri...

In stream processing, elasticity is often realized by adapting the system scale and topology according to the volume of input data. However, this volume is often fluctuating, with a high degree of noise, which can trigger a high amount of scaling operations. Since these scaling operations introduce additional overhead and cost, systems employing su...

The advent of the Internet of Things (IoT) leads to the pervasion of business and private spaces with ubiquitous, networked computing devices. These devices do not simply act as sensors, but feature computational, storage, and networking resources. These resources are close to the edge of the network, and it is a promising approach to exploit them...

In order to keep up with the flexibility and cost-efficiency requirements, the manufacturing industry has begun a transformation process towards a service-oriented production approach. This approach is in line with the cloud manufacturing paradigm that applies established concepts from cloud computing to the manufacturing domain. Although the cloud...

Cloud Manufacturing is a recent concept to realize real-world manufacturing processes by applying a combination of well-known principles from the fields of Cloud Computing, Business Process Management (BPM), and Internet of Things (IoT) to the manufacturing domain. Cloud Manufacturing assumes using crowdsourcing and outsourcing types of business mo...

In order to meet the demands of today’s manufacturing industry, ICT systems need to be able to support highly flexible and scalable inter-organisational manufacturing processes. One recent approach to achieve this, is to bring forward well-known principles from the field of Cloud Computing to the manufacturing domain, thus achieving Cloud Manufactu...