Dielectrophoretic actuation in a microfluidic system with coplanar electrode configuration. - In: IEEE BioSensors 2023 conference proceedings, (2023), insges. 4 S.
This paper presents the analysis of the motion characteristics of droplet transport induced by liquid dielectrophoresis (LDEP). Hereby, a novel fluidic system is demonstrated, which enables droplet transport across a planar surface using a coplanar electrode configuration with adjacent electrodes. The droplet displacement is analyzed by high-speed video imaging and digital image processing. It is demonstrated that droplet motion can be initiated through simplified electrode geometries and the experimental results provide deeper insights into LDEP driven droplet manipulation.
https://doi.org/10.1109/BioSensors58001.2023.10280792
Delay-based reservoir computing with spin-VCSELs: interplay between internal dynamics and performance. - In: 2023 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), (2023), insges. 1 S.
Machine learning setups that are able to process data in the optical domain are ideal for on -chip hardware implementations [1]. Due to the fact that the training of hardware based solutions is complicated, a delay-based reservoir computing (RC) realization, where only the output weights need to be trained via linear regression, is very promising [2]. In this paper we investigate vertical cavity surface emitting laser with two mode emission (spin-VCSEL) as the nonlinear node for a delay-based RC setup. These lasers have the ability to exibit reprodicible and high speed dynamics [3] and are thus ideal candidates to increase the data injection rates which are limited by the clocktime [4], [5]. The focus of our numerical investigations is on the interplay between the internal charge carrier dynamics of the spin-VCSEL and its performance when operated in a delay-based RC setup with optically-injected phase-modulated data injection.
https://doi.org/10.1109/CLEO/Europe-EQEC57999.2023.10232555
Mechanics of leukemic T-cell. - In: Journal of molecular recognition, ISSN 1099-1352, Bd. 36 (2023), 7, e3019, S. 1-7
Cell mechanics is a factor that determines cell growth, migration, proliferation, or differentiation, as well as trafficking inside the cytoplasm and organization of organelles. Knowledge about cell mechanics is critical to gaining insight into these biological processes. Here, we used atomic force microscopy to examine the elasticity, an important parameter of cell mechanics, of non-adherent Jurkat leukemic T-cells in both interphase and mitotic phases. We found that the elasticity of an individual cell does not significantly change at interphase. When a cell starts to divide, its elasticity increases in the transition from metaphase to telophase during normal division while the cell is stiffened right after it enters mitosis during abnormal division. At the end of the division, the cell elasticity gradually returned to the value of the mother cell. These changes may originate from the changes in cell surface tension during modulating actomyosin at the cleavage furrow, redistributing cell organelles, and constricting the contractile ring to sever mother cell to form daughters. The difference in elasticity patterns suggests that there is a discrepancy in the redistribution of the cell organelles during normal and abnormal division.
https://doi.org/10.1002/jmr.3019
Bi-isotropic prolate rotational ellipsoid in a homogeneous axial electric field. - In: 2023 58th International Scientific Conference on Information, Communication and Energy Systems and Technologies (ICEST), (2023), S. 261-264
A bi-isotropic prolate rotational ellipsoid in a homogeneous axial electric field is considered in this paper. By solving of Laplace's and Poisson's equation, the expressions for electric and magnetic scalar potential and electric and magnetic field, inside and outside of an ellipsoid, are completely determined. In the case of bi-isotropic parameter equal to zero, they reduce to known expressions of a pure dielectric ellipsoid. Polarization in the bi-isotropic ellipsoid is determined as well.
https://doi.org/10.1109/ICEST58410.2023.10187315
Time variant directional multi-link channel sounding and estimation for V2X. - In: 2023 IEEE 97th Vehicular Technology Conference (VTC2023-Spring), (2023), insges. 5 S.
We present our new scalable multi-channel and multi-node sounder, the ILMSound G3 . It is configurable in terms of the number of switched Tx and parallel Rx nodes. The basic structures of the Tx and Rx nodes are given with consideration of the measurement system requirements.The ILMSound G3 is validated via a proof of concept measurement at 2.53 GHz in an urban environment. The system was configured as a sounder with two Tx nodes and one Rx node, which records two MIMO links simultaneously. Each node uses an antenna array. The transmitters were moved by cars whereas the receiver was elevated 20 m above the ground by a lifting platform acting as a base station. The used system configuration results in a snapshot rate of approx. 0.5 kHz, which covers the expected time variance of the chosen environment.The measurement results were analyzed using HRPE, providing a parametric description of the specular propagation paths of the radio channel per measurement link. Each estimated path is described by its directions of departure and arrival, delay, Doppler shift, and fully polarimetric complex path weights.
https://doi.org/10.1109/VTC2023-Spring57618.2023.10199213
Sensing resources reduction for vehicle detection with integrated sensing and communications. - In: 2023 IEEE 97th Vehicular Technology Conference (VTC2023-Spring), (2023), insges. 5 S.
Integrated Sensing and Communications (ISAC) aims at incorporating radar and communications functionalities into a single system, achieving higher spectral efficiency through their joint operation. This paper proposes a methodology for reducing resource elements and scanning beams used in the target detection stage of ISAC. Building upon the well-known symbol domain Orthogonal Frequency Division Multiplexing (OFDM) ISAC processing algorithm, its relevant characteristics and limits are considered to minimize the periodicity of sensing resource elements. Moreover, a methodology for finding the required beams to sense a scenario using the radar range equation in a link-budget analysis is proposed and later illustrated via simulations. The simulations show that it is possible to cover a road scenario using a limited number of beams and resource elements from a New Radio (NR) OFDM frame.
https://doi.org/10.1109/VTC2023-Spring57618.2023.10199358
Combination of measurement and simulation for fast virtual drive testing. - In: 2023 IEEE International Symposium on Antennas and Propagation (and USNC-URSI Radio Science Meeting), (2023), S. 25-26
Virtual Drive Test (VDT) is an area of great interest for both scientific research and industry. The objective of VDT is to emulate a real-world communication testing by approximation of defined conditions. VDT can be performed in measurement facilities with over-the-air approaches and channel emulation techniques [1] [2], by simulation-based software-in-the-loop tests [3] or by combining measurement and simulation [4]. For all possible solutions, the challenge of the scientific community is to look for an automated, controllable, repeatable, and reliable procedure, which can considerably reduce testing time and costs. In this paper we present a new VDT technique to evaluate the V2X communications performances based on the combination of measurement and simulation. In particular, the radiation performance of a DUT representing the antenna under test installed on a vehicle is tested in a measurement facility, the radiation pattern (vehicle equipped by the antenna) is integrated in a simulation of a realistic scenario to reproduce a real-world communication testing. The accuracy of the method is validated by comparison with results of measured data from Field Operational Test (FoT) of LTE links [5] [6].
https://doi.org/10.1109/USNC-URSI52151.2023.10237776
Advanced soft-sensor systems for process monitoring, control, optimisation, and fault diagnosis. - In: IFAC-PapersOnLine, ISSN 2405-8963, Bd. 56 (2023), 2, S. 11768-11777
As processes become more complex and the need to measure each and every variable becomes more critical, the ability of physical sensors to always provide the sufficient accuracy and sampling time can be difficult. For many complex systems, such as nonideal mixtures, multiphase fluids, and solid-based systems, it may not be possible to even use a physical sensor to measure the key variables. For example, in a multiphase fluid, the concentration or density may only be able to be accurately estimated using a laboratory procedure that can only produce a limited number of samples. Similarly, the quality variables of steel may only be determinable once the final steel product has been produced, which limits the ability to effectively control the process with small time delays. In such cases, recourse has to be made to soft sensors, or mathematical models of the system that can be used to forecast the difficult-to-measure variables and allow for real-time process monitoring, control, and optimisation. Although the development of the soft-sensor model is well-established, the various applications and use cases have not been often considered and the key challenges examined. It can be seen that soft sensors have been applied to a wide range of processes from simple, chemical engineering systems to complex mining processes. In all cases, major improvements in the process operations have been observed. However, key challenges remain in updating the soft-sensor models over time, combining laboratory measurements, especially when they are infrequent or of uncertain quality, and the development of soft sensors for new conditions or processes.
https://doi.org/10.1016/j.ifacol.2023.10.565
Developing a computer programme for data quality assessment. - In: IFAC-PapersOnLine, ISSN 2405-8963, Bd. 56 (2023), 2, S. 11784-11789
With the increase in the available data, it becomes increasingly important to develop automatic methods that can extract valuable nuggets of information from the dregs of uninformative and useless information for use in system identification. This paper presents an overview and summary of this field's current state of the art. A MATLAB programme is presented that can implement data quality assessment. A brief tutorial is presented using industrial kerosene freeze-point data to partition the data set into good and bad regions for system identification. A model is developed using the partitioned data. It is shown that the resulting four models can accurately predict the kerosene freeze point in their respective regions and across the data set.
https://doi.org/10.1016/j.ifacol.2023.10.568
Concurrent monitoring and isolation of static deviations and dynamic anomalies with a sparsity constraint. - In: IFAC-PapersOnLine, ISSN 2405-8963, Bd. 56 (2023), 2, S. 11790-11795
In modern process industries, elaborate monitoring and isolation of various disturbances and faults are needed for reliable and efficient system operation. The classic process-monitoring and fault-diagnosis methods can grasp the correlation between variables, and thus, only take care of abnormal situations caused by the corruption of the correlation relationship. However, dynamics anomalies are even more noteworthy as they reflect more internal details of the system dynamic behaviour under specific situations, and more importantly, can cause severe failures and spread to a broader range of areas while evolving over time. In this paper, a monitoring-and-isolation strategy is proposed to concurrently detect and isolate faults of static deviations and dynamic anomalies. The natural sparsity of the faulty variables is used to overcome the limitations of unknown fault directions and insufficient erroneous measurements, thereby translating the isolation problem into a quadratic programming problem with a sparsity constraint and solved by the least absolute shrinkage and selection operator (LASSO). The case study shows the advantages of the proposed method in monitoring and isolating static deviations and dynamic anomalies.
https://doi.org/10.1016/j.ifacol.2023.10.570