Refine
Year of publication
Document Type
- Article (14)
- Conference Proceeding (13)
- Report (2)
- Master's Thesis (1)
Language
- English (30) (remove)
Has Fulltext
- yes (30)
Is part of the Bibliography
- no (30)
Keywords
- PROFInet (6)
- Energiemanagement (5)
- Ethernet (5)
- Energieeffizienz (4)
- Herbarium (4)
- Angewandte Botanik (3)
- Computersicherheit (3)
- Digitalisierung (3)
- Erkennungssoftware (3)
- Ethernet-APL (3)
Institute
- Fakultät I - Elektro- und Informationstechnik (30) (remove)
The research project "Herbar Digital" was started in 2007 with the aim to digitize 3.5 million dried plants on paper sheets belonging to the Botanic Museum Berlin in Germany. Frequently the collector of the plant is unknown, so a procedure had to be developed in order to determine the writer of the handwriting on the sheet. In the present work the static character was transformed into a dynamic form. This was done with the model of an inert ball which was rolled along the written character. During this off-line writer recognition, different mathematical procedures were used such as the reproduction of the write line of individual characters by Legendre polynomials. When only one character was used, a recognition rate of about 40% was obtained. By combining multiple characters, the recognition rate rose considerably and reached 98.7% with 13 characters and 93 writers (chosen randomly from the international IAM-database [3]). A global statistical approach using the whole handwritten text resulted in a similar recognition rate. By combining local and global methods, a recognition rate of 99.5% was achieved.
The methods developed in the research project "Herbar Digital" are to help plant taxonomists to master the great amount of material of about 3.5 million dried plants on paper sheets belonging to the Botanic Museum Berlin in Germany. Frequently the collector of the plant is unknown. So a procedure had to be developed in order to determine the writer of the handwriting on the sheet. In the present work the static character is transformed into a dynamic form. This is done with the model of an inert ball which is rolled through the written character. During this off-line writer recognition, different mathematical procedures are used such as the reproduction of the write line of individual characters by Legendre polynomials. When only one character is used, a recognition rate of about 40% is obtained. By combining multiple characters, the recognition rate rises considerably and reaches 98.7% with 13 characters and 93 writers (chosen randomly from the international IAM-database [3]). Another approach tries to identify the writer by handwritten words. The word is cut out and transformed into a 6-dimensional time series and compared e.g. by means of DTW-methods. A global statistical approach using the whole handwritten sentences results in a similar recognition rate of more than 98%. By combining the methods, a recognition rate of 99.5% is achieved.
In the area of manufacturing and process automation in industrial applications, technical energy management systems are mainly used to measure, collect, store, analyze and display energy data. In addition, PLC programs on the control level are required to obtain the energy data from the field level. If the measured data is available in a PLC as a raw value, it still has to be processed by the PLC, so that it can be passed on to the higher layers in a suitable format, e.g. via OPC UA. In plants with heterogeneous field device installations, a high engineering effort is required for the creation of corresponding PLC programs. This paper describes a concept for a code generator that can be used to reduce this engineering effort.
With the use of an energy management system in an industrial company according to ISO 50001, a step-by-step increase in energy efficiency can be achieved. The realization of energy monitoring and load management functions requires programs on edge devices or PLCs to acquire the data, adapt the data type or scale the values of the energy information. In addition, the energy information must be mapped to communication interfaces (e.g. based on OPC UA) in order to convey this energy information to the energy management application. The development of these energy management programs is associated with a high engineering effort, because the field devices from the heterogeneous field level do not provide the energy information in standardized semantics. To mitigate this engineering effort, a universal energy data information model (UEIM) is developed and presented in this paper.
Toward a service-based workflow for automated information extraction from herbarium specimens
(2018)
Over the past years, herbarium collections worldwide have started to digitize millions of specimens on an industrial scale. Although the imaging costs are steadily falling, capturing the accompanying label information is still predominantly done manually and develops into the principal cost factor. In order to streamline the process of capturing herbarium specimen metadata, we specified a formal extensible workflow integrating a wide range of automated specimen image analysis services. We implemented the workflow on the basis of OpenRefine together with a plugin for handling service calls and responses. The evolving system presently covers the generation of optical character recognition (OCR) from specimen images, the identification of regions of interest in images and the extraction of meaningful information items from OCR. These implementations were developed as part of the Deutsche Forschungsgemeinschaft funded a standardised and optimised process for data acquisition from digital images of herbarium specimens (StanDAP-Herb) Project.
This paper reflects the content of the presentation “The Next Generation: Ethernet-APL for Safety Systems” at the NAMUR Annual General Meeting 2022. It deals with the use of the Ethernet Advanced Physical Layer (Ethernet-APL) in combination with the PROFINET/PROFIsafe protocol for safety applications. It describes the virtues of the digital communication between the field and safety system. In parallel the aspect of OT security for this use case is touched as well. The paper proposes a secure architecture, where safety- and non-safety field communications are still separated. At the end a set of requirements for the development of future APL devices is described.
The Ethernet-APL Engineering Process - A brief look at the Ethernet-APL engineering guideline
(2021)
The vision of an “Industrial Ethernet down to the sensors and actors” has become reality. At the Achema fair in June 2021 Ethernet-APL was introduced. This technology is based on a 2-wire Ethernet that conveys information as well as energy to the sensors and actuators of the automation system. Ethernet-APL is based on the 2-wire Ethernet standard IEEE 802.3cg running at 10 Mbit/s. An additional specification, the Ethernet-APL Port Profile Specification, defines additional parameters for the use of the technology in the process industry, especially in areas with potentially explosive atmospheres. As a next step, potential users need to become familiar with the engineering process of Ethernet-APL networks. For this purpose, the Ethernet-APL project provides the Ethernet-APL Engineering Guideline that covers the main areas of planning, installation and acceptance testing.
Operators of production plants are increasingly emphasizing secure communication, including real-time communication, such as PROFINET, within their control systems. This trend is further advanced by standards like IEC 62443, which demand the protection of realtime communication in the field. PROFIBUS and PROFINET International (PI) is working on the specification of the security extensions for PROFINET (“PROFINET Security”), which shall fulfill the requirements of secure communication in the field.
This paper discusses the matter in three parts. First, the roles and responsibilities of the plant owner, the system integrator, and the component provider regarding security, and the basics of the IEC 62443 will be described. Second, a conceptual overview of PROFINET Security, as well as a status update about the PI specification work will be given. Third, the article will describe how PROFINET Security can contribute to the defense-in-depth approach, and what the expected operating environment is. We will evaluate how PROFINET Security contributes to fulfilling the IEC 62443-4-2 standard for automation components.
Two of the authors are members of the PI Working Group CB/PG10 Security.
Conventional fluorescent tubes are increasingly being replaced with innovative light-emitting diodes (LEDs) for lighting poultry houses. However, little is known about whether the flicker frequencies of LED luminaires are potential stressors in poultry husbandry. The term “light flicker” describes the fluctuations in the brightness of an electrically operated light source caused by the design and/or control of the light source. In this context, the critical flicker frequency (CFF) characterizes the frequency at which a sequence of light flashes is perceived as continuous light. It is known that CFF in birds is higher than that in humans and that light flicker can affect behavioral patterns and stress levels in several bird species. As there is a lack of knowledge about the impact of flicker frequency on fattening turkeys, this study aimed to investigate the effects of flicker frequency on the behavior, performance, and stress response in male turkeys. In 3 trials, a total of 1,646 male day-old turkey poults of the strain B.U.T. 6 with intact beaks were reared for 20 wk in 12 barn compartments of 18 m² each. Each barn compartment was illuminated using 2 full-spectrum LED lamps. Flicker frequencies of 165 Hz, 500 Hz, and 16 kHz were set in the luminaires to illuminate the compartments. Analyses of feather corticosterone concentration were performed on fully grown third-generation primaries (P 3) of 5 turkeys from each compartment. No significant differences were found in the development of live weight, feed consumption, or prevalence of injured or killed turkeys by conspecifics reared under the above flicker frequencies. The flicker frequencies also did not significantly influence feather corticosterone concentrations in the primaries of the turkeys. In conclusion, the present results indicate that flicker frequencies of 165 Hz or higher have no detrimental effect on growth performance, injurious pecking, or endocrine stress response in male turkeys and, thus, may be suitable for use as animal-friendly lighting.
Requirements for an energy data information model for a communication-independent device description
(2021)
With the help of an energy management system according to ISO 50001, industrial companies obtain the opportunities to reduce energy consumption and to increase plant efficiencies. In such a system, the communication of energy data has an important function. With the help of so-called energy profiles (e.g. PROFIenergy), energy data can be communicated between the field level and the higher levels via proven communication protocols (e.g. PROFINET). Due to the fact that in most cases several industrial protocols are used in an automation system, the problem is how to transfer energy data from one protocol to another with as less effort as possible. An energy data information model could overcome this problem and describe energy data in a uniform and semantically unambiguous way. Requirements for a unified energy data information model are presented in this paper.
PROFINET Security: A Look on Selected Concepts for Secure Communication in the Automation Domain
(2023)
We provide a brief overview of the cryptographic security extensions for PROFINET, as defined and specified by PROFIBUS & PROFINET International (PI). These come in three hierarchically defined Security Classes, called Security Class 1, 2 and 3. Security Class 1 provides basic security improvements with moderate implementation impact on PROFINET components. Security Classes 2 and 3, in contrast, introduce an integrated cryptographic protection of PROFINET communication. We first highlight and discuss the security features that the PROFINET specification offers for future PROFINET products. Then, as our main focus, we take a closer look at some of the technical challenges that were faced during the conceptualization and design of Security Class 2 and 3 features. In particular, we elaborate on how secure application relations between PROFINET components are established and how a disruption-free availability of a secure communication channel is guaranteed despite the need to refresh cryptographic keys regularly. The authors are members of the PI Working Group CB/PG10 Security.
An important part of computed tomography is the calculation of a three-dimensional reconstruction of an object from series of X-ray images. Unfortunately, some applications do not provide sufficient X-ray images. Then, the reconstructed objects no longer truly represent the original. Inside of the volumes, the accuracy seems to vary unpredictably. In this paper, we introduce a novel method to evaluate any reconstruction, voxel by voxel. The evaluation is based on a sophisticated probabilistic handling of the measured X-rays, as well as the inclusion of a priori knowledge about the materials that the object receiving the X-ray examination consists of. For each voxel, the proposed method outputs a numerical value that represents the probability of existence of a predefined material at the position of the voxel while doing X-ray. Such a probabilistic quality measure was lacking so far. In our experiment, false reconstructed areas get detected by their low probability. In exact reconstructed areas, a high probability predominates. Receiver Operating Characteristics not only confirm the reliability of our quality measure but also demonstrate that existing methods are less suitable for evaluating a reconstruction.
Network convergence is an increasing trend in the automation domain. More and more plant owners strive for a unification of networks in their plants. This yields a seamless network structure, simplified supervision, and reduced training effort for the personnel, as only one unified network technology needs to be handled. Ethernet-APL is one piece of the puzzle for such a converged network, supporting various real time protocols like PROFINET, EtherNet, HART-IP as well as the middleware protocol OPC UA. This paper gives an overview on the impact of Ethernet-APL field devices to OT security and proposes how to ensure OT security for them.
The growing importance of renewable generation connected to distribution grids requires an increased coordination between transmission system operators (TSOs) and distribution system operators (DSOs) for reactive power management. This work proposes a practical and effective interaction method based on sequential optimizations to evaluate the reactive flexibility potential of distribution networks and to dispatch them along with traditional synchronous generators, keeping to a minimum the information exchange. A modular optimal power flow (OPF) tool featuring multi-objective optimization is developed for this purpose. The proposed method is evaluated for a model of a real German 110 kV grid with 1.6 GW of installed wind power capacity and a reduced order model of the surrounding transmission system. Simulations show the benefit of involving wind farms in reactive power support reducing losses both at distribution and transmission level. Different types of setpoints are investigated, showing the feasibility for the DSO to fulfill also individual voltage and reactive power targets over multiple connection points. Finally, some suggestions are presented to achieve a fair coordination, combining both TSO and DSO requirements.
Industrial Control Systems (ICS) succumb to an ever evolving variety of threats. Additionally, threats are increasing in number and get more complex. This requires a holistic and up-to-date security concept for ICS as a whole. Usually security concepts are applied and updated based on regularly performed ICS security assessments. Such ICS security assessments require high effort and extensive knowledge about ICS and its security. This is often a problem for small and mediumsized enterprises (SME), which do not have sufficient respective sufficiently skilled human resources. This paper defines in a first step requirements on the knowledge needed to perform an ICS security assessment and the life cycle of this knowledge. Afterwards the ICS security knowledge and its life cycle are developed and discussed considering the requirements and related work.
As a result of a research semester in the summer of 2022, a bibliography on multimodality in technical communication (TC) is presented. Given that TC primarily involves the development of instructional information, this bibliography holds relevance for anyone interested in the use of multimodality in the communication of procedural knowledge. The bibliography is publicly accessible as Zotero group library (https://bit.ly/multimodality_in_tc) and can be used and expanded.
After a description of the objectives and target group, the five disciplines from which the publications in the bibliography originate are presented. This is followed by information on the structure and search options of the Zotero group library, which are intended to support the search for publications on the respective research interest. The article concludes with some suggestions for collaborative efforts aimed at further enhancing and expanding the bibliography.
The author actively maintains the group library. Individuals seeking to contribute publications to the group library will receive the appropriate access rights from the author (claudia.villiger@hs-hannover.de). The author aspires to foster collaboration among researchers from diverse fields through this bibliography.
Quartz-crystal microbalances (QCMs) are commercially available mass sensors which mainly consist of a quartz resonator that oscillates at a characteristic frequency, which shifts when mass changes due to surface binding of molecules. In addition to mass changes, the viscosity of gases or liquids in contact with the sensor also shifts the resonance but also influences the quality factor (Q-factor). Typical biosensor applications demand operation in liquid environments leading to viscous damping strongly lowering Q-factors. For obtaining reliable measurements in liquid environments, excellent resonator control and signal processing are essential but standard resonator circuits like the Pierce and Colpitts oscillator fail to establish stable resonances. Here we present a lowcost, compact and robust oscillator circuit comprising of state-of-the-art commercially available surface-mount technology components which stimulates the QCMs oscillation, while it also establishes a control loop regulating the applied voltage. Thereby an increased energy dissipation by strong viscous damping in liquid solutions can be compensated and oscillations are stabilized. The presented circuit is suitable to be used in compact biosensor systems using custom-made miniaturized QCMs in microfluidic environments. As a proof of concept we used this circuit in combination with a customized microfabricated QCM in a microfluidic environment to measure the concentration of C-reactive protein (CRP) in buffer (PBS) down to concentrations as low as 5 μgmL -1.
This document concerns IT security in production facilities. It is intended for small and medium-sized enterprises that are looking for a simple procedural model for ensuring IT security in production areas.
In order to raise readers’ awareness of IT security in production facilities, security incidents are presented in section 2. It is clear that cyber attacks on production facilities in this day and age are not random, but are instead based on a targeted process.
An overview of the most important standards and recommendations on the topic of “IT security in production” then follows in section 3.
Section 4 develops a concept for setting up an IT security system for small and medium-sized enterprises (SMEs) on the basis of a ten-point plan. The focus is not only on technical measures, but also in particular on the most frequently neglected organizational measures.
Section 5 then describes the outlook for future requirements and solutions in the context of Industry 4.0.
The impact of vertical and horizontal integration in the context of Industry 4.0 requires new concepts for the security of industrial Ethernet protocols. The defense in depth concept, basing on the combination of several measures, especially separation and segmentation, needs to be complimented by integrated protection measures for industrial real-time protocols. To cover this challenge, existing protocols need to be equipped with additional functionality to ensure the integrity and availability of the network communication, even in environments, where possible attackers can be present. In order to show a possible way to upgrade an existing protocol, this paper describes a security concept for the industrial Ethernet protocol PROFINET.
The trend towards the use of Ethernet in automation networks is ongoing. Due to its high flexibility, speed, and bandwidth, Ethernet nowadays is not only widely used in homes and offices worldwide but finding its way into industrial applications. Especially in automation processes, where many field devices send data in relative short time spans, the requirements for a safe and fast data transfer are high. This makes the use of industrial Ethernet essential. A new hardware-layer, specifically tailored for industrial applications, has been introduced in the form of Ethernet-APL (‘Advanced Physical Layer’). Ethernet-APL is based on the Ethernet standard and implements a two-wire Ethernet-based communication for field devices and provides data and power over a two-wire cable. The operation in areas with potentially explosive atmosphere is also possible. This enables a modular, fast, and transparent Ethernet network structure throughout the entire plant. However, by integrating Ethernet-APL into the field, industrial networks in the future will face the challenge of operating at varying datarates at different locations in the network, resulting in a ‘mixed link speed’ network. This can lead to limitations in packet-throughput and consequently to potential packet loss of system relevant data, which must be avoided. Therefore, the purpose of this thesis is to investigate the potential of packet loss in ‘mixed link speed’ networks.