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For the third time we were able to hold our PhD workshop "Research is Calling" on smart medical devices and systems, this time in Berlin again. This unique workshop brings together young scientists from computer science and medicine to provide a forum to discuss the very latest approaches to smart medical devices and systems. This year, for the first time, it is possible to publish corresponding workshop proceedings via the publication service of the Brandenburg Technical University (BTU). In our view, this format can create true interdisciplinarity because everyone presents their ideas and interim results to colleagues from a wide variety of disciplines and, conversely, hears and sees the latest from many other specialties. This forum is the vehicle for initiating new collaborations and planning joint research projects. The 'Cottbus project' emerged from personal partnerships between 'technicians' and 'physicians' and was planned from the beginning as a platform and an offer: as a platform for free and fully open scientific exchange and discourse, as an offer to all who are interested, also and gladly beyond Brandenburg. Begun as a "PhD Colloquium", Cottbus' "Research is Calling" is an ideas laboratory for young scientists. Cottbus is to establish a university medical faculty in the next few years as part of the structural change program following the coal phase-out. From our point of view, this lab is an important building block to establish cross-sectional issues right at the interface between medicine and technology, a culture of open discourse and scientific dialogue. The workshop covers the following topics in particular: Smart sensors for medical applications, Low-power wearable sensors, artificial intelligence for medical applications, medical robots, algorithms for medical applications, applications and case studies. Despite the pandemic situation the workshop could be held in presence. In five exciting presentations new ideas and cooperation possibilities were shown. Two keynotes (including Alina Nechyporenko, Marcus Frohme as special guests) and a dinner rounded off the program. At this point we would like to thank all participants, the reviewers, and the organizers, Stefan Scharoba and Kathleen Galke. We look forward to establishing this event as permanent and reaching an ever-growing audience.
Indawgyi Lake is one of the largest lakes in East Asia. Due to its habitat diversity and its great importance for international bird migration, it has the status of an UNESCO biosphere reserve. In the last decades, anthropogenic pressures on the lake due to increasing population numbers, overfishing and intensification of agriculture and forestry as well as to the impacts by artisanal small-scale gold mining in the catchment area have increased sharply. As a result of gold mining, lake inflows have very high suspended matter loads, both from the washing of gold-bearing sediments and from soil erosion as a result of the destruction of the floodplain and of the forest close to the river. The input of sediments and suspended matter from the Hkaung Tung Hka Chaung River has led to massive deposits of river sediments in the southern part of Indawgyi Lake within a few years.
In the context of short-term investigations and a one-year monitoring close to the stream mouth, the extent of the suspended matter input from Hkaung Tung Hka Chaung River into Indawgyi Lake was estimated and heavy metal pollution concentrations of the suspended matter were measured as a basis for recommendations for the reduction of the pollution pressure on the lake.
Sedimentation analyses showed that the river water was still very turbid even after 50 hours due to high concentrations of very small solids. In contrast, material in the size of sand grains settled completely after about ten hours. The clay fraction of the suspended matter was heavily contaminated by different heavy metals, including cadmium, copper, nickel, chromium and lead.
The load of suspended matter was subject to strong fluctuations and showed no correlation with the discharge. The mean concentration of suspended matter was 9.6 g/L (as dry weight per volume of water). The daily dry matter load in Hkaung Tung Hka Chaung River varied between 2.3 and 2,900 t. The mean load was 359 t/d, with by far the largest amount being transported by the river during the rainy season during times of high discharge. That indicates that, in addition to direct inputs from mining activity, there was also suspended matter input from soil erosion and from the remobilization of river sediments. The estimates of the annual input into Indawgyi Lake came to an amount of about 133,000 t. This corresponds to a volume of the fresh matter between 0.26 and 0.4 million m³.
The results show the urgent need for a control of the artisanal small-scale gold mining activities and for the building of sedimentation basins at Hkaung Tung Hka Chaung River to protect Indawgyi Lake with its highly valuable ecosystem.
Today, urban conservation scholarship calls for case studies that problematise universal conservation principles in local planning circumstances, particularly in countries from which modern conservation has not originated. In this series of workshops, we discuss singularities of urban conservation and the protection of historic urban areas with local experts who have been directly involved in processes of putting conservation policy documents into practice. We discuss how the planned goals of conservation projects are influenced by unplanned factors such as war, economic and political instability, inter-organisational conflicts, and natural hazards. The discussed cases represent cities with non-western cultural backgrounds that are geographically and culturally interconnected. By discussing urban conservation issues in Ankara, Baghdad, Tehran, Shiraz, Yazd, Kerman, Herat, and Mumbai, we aim to reflect on the functionality of mainstream conservation approaches in local conditions. The speakers share their local insight into obstacles of realising the international conservation models under rapidly changing natural and socio-political conditions. The workshops' moderators are outstanding young academics who have a deep understanding of the discussed issues and have co-planned the sessions with the speakers. This series of events is cooperatively organised by the Chair Urban Management and the DFG Training Group 1913, "Cultural and Technological Significance of Historic Buildings" in the framework of the DFG project, Assembling Iran's Urban Heritage Conservation Policy and Practice: Problematised in Tehran.
As the architectural walls drive the number of parallel cores in multicore systems up, it becomes harder to maintain cache coherence across all of the physical memory and all cores. On the other hand, even given a performant cache-coherent system, the unavoidable non-uniform memory (NUMA) and non-uniform cache (NUCA) architectures make programming for it difficult.
A potential solution to this problem is to interpret massive multicore machines as a distributed system with remote memory access, and therefore, use existing distributed programming models. A natural fit for such an approach is the PGAS model, which provides a global address space divided into partitions that can be either local or remote. Unfortunately, completely discarding the notion of sharing ignores the efficient hardware mechanisms available in multicore machines with shared memory.
This survey examines PGAS frameworks and communication libraries with an focus on the PGAS model to enable PGAS applications to exploit shared memory in massive multicore machines without sacrificing the benefits of the PGAS programming model.
Convolutional neural networks are often successfully used for classification problems. Usually, a huge number of weights need to be learnt by use of training data. However, the learnt weights give no insight how the cnn really works. Thus, a cnn can be seen as a black box solution. In our approach we develop a method to generate a commuting quantum query language (cqql) condition from a sample derived from a given cnn or from training input. CQQL is inspired by quantum logic and its conditions obey the rules of Boolean algebra. The evaluation of a cqql condition provides values from the unit interval [0; 1] and establishes therefore an elegant bridge between logic and a cnn. The underlying assumption is that a condition (a logic expression) gives much more understanding than pure cnn weights. Furthermore, the rich theory of Boolean algebra can be used for manipulating logic expressions. After extracting a cqql condition from a cnn or its training data we can use logic as a way to predict classes alternatively to a cnn.
The Agile Manifesto titled “Working software over comprehensive documentation”. Although the stated principle makes an important point, it should not follow that documentation becomes obsolete. On the contrary, agile software development (ASD) is based on frequent decisions focused on customer benefits. Those decisions guide further development, subsequent maintenance, and software evolution and are made during every stage of the software development cycle. Thus, documenting the most important ones is an important foundation fostering product comprehension, software quality, and customer benefit. Besides, preserving decision knowledge supports refactoring and, thus, diminishing software erosion.
However, all these beneficial properties are opposed by a dismissive attitude among software developers. Documentation is very unpopular among software developers, especially in the ASD community. A common interpretation of the agile manifesto at this point is that good and functional code can fully replace documentation. Among other reasons, this attitude is the reason for the sparse application of structured and systematic documentation of decisions and their rationale.
To shed more light on imponderables, developer’s desires regarding decision documentation, and assess the outlined perception of a lack of decision documentation, this paper reports a survey on decision documentation in Scrum among industry practitioners. The author assesses to what extent the above claims hold by asking industry practitioners about their perceptions and applied practices regarding decision documentation in Scrum. Therefore, the author conducted a large-scale survey in the German and English speaking Scrum community. A few more than 100 software developers were asked what they document, how they document and how they use/share produced documentation.
The findings of this report reveal that there is a wide range of opinions in the agile community. The responses show that a developer’s experience significantly impacts the documentation frequency and the interest in the available documentation. Similarly, the role in which software developers have operated in Scrum plays a significant role in the frequency of documentation and the timing when developers document.
Tattoo taboo : a reader
(2020)
In different parts of the world, tattoos historically have been expression of the socio-cultural identity of individuals or communities: Tattoos are firmly integrated into social practices as elements of initiation or marriage, in other parts of the world, however, tattoos carry negative associations being linked to immorality, and crime.
To research the practice of and places associated with tattooing a research-based study project was designed to address the practice of tattooing from the point of view of its cultural heritage values, both intangible and tangible. In the winter semester 2018/2019 this study project was offered jointly by the Chair of Architectural Conservation and the Department of Heritage Management at the Brandenburg University of Technology (BTU) Cottbus-Senftenberg. Twelve international students from the study programmes World Heritage Studies and Architecture participated in this study project, which included a field trip to London and Oxford and several interviews and interactions with researchers and academics from the fields of tattoo history, anthropology, medical sciences and museography.
A collection of students’ essays on this topic is presented in this reader with a particular focus on the tangible and intangible aspects of tattooing, and the spatial history of tattooing based on two distinct areas in London as a case study.
The papers are divided into three distinctive themes that are linked to the practice of tattooing. Section one is dedicated to tattoos as a form of heritage, the one to tattooing as a form of art, and the last one to mapping as a methodological tool to visualise, assess and present relationships between heritage, tattooing practice and its connection to the social fabric in London at the turn of the penultimate century.
The Digital Twin is seen as the step towards digitalization in many areas, including the area of manufacturing which is the focus of this paper. However, the frequently application-oriented development of concepts and initial implementations make it difficult to adapt them to other applications. Especially when production deviates from the usual highly automated processes and requires high flexibility, e.g. to allow batch size one. In such a case, the Digital Twin must support modular shopfloors with flexible areas in which different production times and various tools and machines are used. It should also be possible to react promptly to problems in production. Design errors that only become apparent during production must be reported directly. In order to deal with this problem, the paper presents a concept for an abstract representation of a Digital Shadow (DS). The DS combines the disciplines of production planning and control, product lifecycle and layout planning which creates new links and enables further application scenarios. Based on this Digital Shadow, different applications can be realized that provide user-related solutions. For this purpose, a tree structure is used that links information about the product and the production environment which in this case is variable.
From Gleason's theorem we know that in principle every probability measure can be expressed by Hermitian operators in a separable Hilbert space and the Born rule as part of a quantum mechanical system. However, that theorem is not constructive. For a given discrete and additive probability measure based on a σ-algebra we construct a quantum system with projectors expressing that probability measure.
Planning the construction of new transport routes or power lines on terrain is usually carried out manually by engineers, with no guarantee of optimality. We introduce a new approach for the computation of an optimal trajectory for the construction of new transit routes and power lines between two locations on a submanifold U _ R3 representing the topography of a terrain. U is approximatively modeled by a special weighted grid. On this grid, the shortest paths for the construction of new routes are determined, whereby we consider three optimization criteria: routes with minimum distance, routes with lowest construction costs and routes with minimum absolute altitude variations or minimum absolute gradients. Subsequently, a combination of these criteria is used to expand this problem into a multi-criteria optimization problem. A shortest path algorithm, such as the Dijkstra algorithm, is used to compute optimal compromises for the construction of new routes.
We present a general numerical solution method for control problems with PDE-defined state variables over a finite set of binary or continuous control variables. We show empirically that a naive approach that applies a numerical discretization scheme to the PDEs (and if necessary a linearization scheme) to derive constraints for a mixed-integer linear program (MILP) leads to systems that are too large to be solved with state-of-the-art solvers for MILPs, especially if we desire an accurate approximation of the state variables. Our framework comprises two techniques to mitigate the rise of computation times with increasing discretization level parameters:
First, the linear system is solved for a basis of the control space in a preprocessing step. Second, certain constraints are just imposed on demand via the IBM ILOG CPLEX feature of a lazy constraint callback. These techniques are compared with an approach where the relations obtained by the discretization of the continuous constraints are directly included in the MILP. We demonstrate our approach on two examples: modeling of the spread of wildfire and the mitigation of water contamination. In both examples the computational results demonstrate that the solution time is significantly reduced by our methods. In particular, the dependence of the computation time on the size of the spatial discretization of the PDE is significantly reduced.
We formulate the mission planning problem for a meet of unmanned aerial vehicles (UAVs) as a mixed-integer nonlinear programming problem (MINLP). The problem asks for a selection of targets from a list to the UAVs, and trajectories that visit the chosen targets. To be feasible, a trajectory must pass each target at a desired maximal distance and within a certain time window, obstacles or regions of high risk must be avoided, and the fuel limitations must be obeyed. An optimal trajectory maximizes the sum of values of all targets that can be visited, and as a secondary goal, conducts the mission in the shortest possible time. In order to obtain numerical solutions to this model, we approximate the MINLP by a mixed-integer linear program (MILP), and apply a state-of-the-art solver (GUROBI) to the latter on a set of test instances.
We deal with a very complex and hard scheduling problem. Several types of products are processed by a heterogeneous resource set, where resources have different operating capabilities and setup times are considered. The processing of the products follows different workflows, allowing also assembly lines. The goal is to process all products in minimum time, i.e., the makespan is to be minimized. Because of the complexity of the problem an exact solver would require too much running time. We propose a compound method where a heuristic is combined with an exact solver. Our proposed heuristic is composed of several phases applying different smart strategies. In order to reduce the computational complexity of the exact approach, we exploit the makespan determined by the heuristic as an upper bound for the time horizon, which has a direct in uence on the instance size used in the exact approach. We demonstrate the efficiency of our combined method on multiple problem classes. With the help of the heuristic the exact solver is able to obtain an optimal solution in a much shorter amount of time.
The multiple traveling salesmen problem with moving targets is a generalization of the classical traveling salesmen problem, where the targets (cities or objects) are moving over time. Additionally, for each target a visibility time window is given. The task is to find routes for several salesmen so that each target is reached exactly once within its visibility time window and the sum of all traveled distances of all salesmen is minimal. We present different modeling formulations for this TSP variant. The time requirements are modeled differently in each approach. Our goal is to examine what formulation is most suitable in terms of runtime to solve the multiple traveling salesmen problem with moving targets with exact methods. Computational experiments are carried out on randomly generated test instances to compare the different modeling approaches. The results for large-scale instances show, that the best way to model time requirements is to directly insert them into a formulation with discrete time steps.
A tourism company that offers fly-in safaris is faced with the challenge to route and schedule its fleet of airplanes in an optimal way. Over the course of a given time horizon several groups of tourists have to be picked up at airports and flown to their destinations within a certain time-window. Furthermore the number of available seats, the consumption of fuel, the maximal takeoff weight, and restrictions on the detour of the individual groups have to be taken into account. The task of optimally scheduling the airplanes and tour groups belongs to the class of vehicle routing problems with pickup and delivery and time-windows. A flow-over-flow formulation on the time expanded graph of the airports was used in the literature in order to model this problem as a mixed integer linear program. Most of the benchmark problems however could not be solved within a time limit of three hours, which was overcome by formulating the problem for a simplified (time-free) graph and the use of an incumbent callback to check for feasibility in the original graph. While this approach led to very good results for instances, where few time-free solutions were infeasible for the original problem, some instances remained unsolved. In order to overcome this problem we derive two new exact formulations that include time as variables. Although these formulations by themselves are not better than the approach from the literature, they allow for an effective construction of graphs which can be interpreted as intermediate graphs between the graph of airports and the expanded graph with vertices for each visit. Using similar relaxation techniques to the time-free approach and constructing these graphs based on solutions of the relaxations guarantees that only critical airports are expanded. A computational study was performed in order to compare the new formulations to the methods from the literature. Within a time limit of 3 hours the new approach was able to find proven optimal solutions for all previously unsolved benchmark instances. Furthermore the average computation time of all benchmark instances was reduced by 90 percent.
MARCIE manual
(2016)
This manual gives an overview on MARCIE – Model Checking And Reachability analysis done effiCIEntly. MARCIE was originally developed as a symbolic model checker for stochastic Petri nets, building on its predecessor – IDDMC – Interval Decision Diagram based Model Checking – which has been previously developed for the qualitative analysis of bounded Place/Transition nets extended by special arcs. Over the last years the tool has been enriched to allow also quantitative analysis of extended stochastic Petri nets. We concentrate here on the user viewpoint. For a detailed introduction to the relevant formalisms, formal definitions and algorithms we refer to related literature.
Hybrid simulation of biological processes becomes widely used to overcome the limitations of the pure stochastic or the complete deterministic simulation. In this manual, we present easy-to-follow steps for constructing and executing hybrid models via Snoopy [HHL+12]. Snoopy is a tool to design and animate or simulate hierarchical graphs, i.e., qualitative, stochastic, continuous, and hybrid Petri nets. This manual is concerned with hybrid Petri nets (HPN) [HH12] as well as their coloured counterpart (HPNC) [HLR14]. HPN combine the merits of stochastic and continuous Petri nets into one single class. Moreover, HPN in Snoopy supports state of the art hybrid simulation algorithms (e.g., [HH16]) to execute the constructed HPN models. Simulating a model using Snoopy's hybrid simulation involves first constructing the reaction network via HPN notations and afterwards executing such model.
Mathematically, cryptographic approaches are secure. This means that the time an attacker needs for finding the secret by brute forcing these approaches is about the time of the existence of our world. Practically, an algorithm implemented in hardware is a device that generates a lot of additional data during calculation. Its power consumption, electromagnetic radiation etc. can be measured, saved and analysed for the key extraction. Such attacks - the side channel analysis attacks (SCA attacks) - are significant threats when applying cryptographic algorithms. By taking the issue of physical attacks into consideration when implementing a cryptographic algorithm, it is possible to design an implementation that is resilient - at least to a certain extend - against side channel analyses. In this report, we give implementation details of the IHP accelerator for the elliptic curve point multiplication. We analysed the implemented algorithm ow and its power consumption using simulated power traces for the 130nm CMOS IHP technology. We made a horizontal power analysis attack using the difference-of-means test with the goal of finding potential SCA leakage sources, i.e. finding the operations in the algorithmic ow that are responsible for the correct extraction of the cryptographic key.
Urbanisation is an extreme case of land-use change. The geographical patterns of urban expansion of a city have a direct relationship with its environmental quality, particularly water flows, flooding and urban thermal stress. A key question for urban policy and planning is how to direct these changes in ways that minimise environmental impacts and risks. Since many of the main impacts of climate change in Ho Chi Minh City additionally exhibit a land use dimension, such as the increased frequency of urban flooding events or the intensification of the already existing urban heat island effect, land-use planning and land-use controls can be seen as the most appropriate adaptation management strategy.
These recommendations have been developed under the German Ministry for Education and Research Funded research project ‘‘Integrative Urban and Environmental Planning for Adaptation of Ho Chi Minh City to Climate Change” which is funded as part of the research programme ‘‘Sustainable Development of the Megacities of Tomorrow’’ by the German Federal Ministry of Education and Research (BMBF) in close cooperation with the Department of Nature Resources and Environment, Ho Chi Minh City.
The main objective was to respond to the needs of the Department of Nature Resource and Environment, Ho Chi Minh City by providing guidance and recommendations that can be used by land-use planners and policy makers to reduce the potential adverse effects of both urbanisation and the current and future effects of climate change. The recommendations have been compiled as a stand-alone document that can be read and understood on their own, however they also contain references to the additional document entitled “Land-use Planning Recommendations - Adaptation Strategies to a Changing Climate in Ho Chi Minh City” referenced within this document as LUPR.Eleven specific focus areas were selected (labelledfrom A to K) in combination with the Department of Natural Resources and Environment. For each area the current situation is described and detailed planning recommendations are provided.
The work described in this report can be broadly divided into two sections. The first section considers two export features. We describe how the export for stochastic Petri nets to SBML level 1 has been added to the Petri net modelling and simulation tool Snoopy. This task was accomplished by making appropriate changes to the existing export code to generate SBML level 2. Also we demonstrate in detail, how the direct export for coloured Petri nets to both levels (i.e. 1 and 2) of SBML was realised. The next section summarises the performed comparison of different stochastic simulation tools for biochemical reaction networks. We first compare BioNetGen and SSC with each other by performing simulations on non-coloured Petri nets. Then, we compare the remaining four tools, i.e. Cain, Marcie, Snoopy and Stochkit with each other by performing simulation on coloured Petri nets.
This work builds on results by Aman Sinha [19].