Design of a Scalable, Flexible, and Durable Thermoelectric Cooling Device for Soft Electronics Using Kirigami Cut Patterns

A flexible, soft thermoelectric cooling device is presented that shows potential for human cooling applications in wearable technologies and close-to-body applications. Current developments lack integration feasibility due to non-scalable assembly procedures and unsuitable materials for comfortable and durable integration into products. Our devices have been created and tested around the need to conform to the human body which we have quantified through the creation of a repeatable drape testing procedure, a metric used in the textile industry. Inspired by mass manufacturing constraints, our flexible thermoelectric devices are created using commercially available materials and scalable processing techniques. Thermoelectric legs are embedded in a foam substrate to provide flexibility, while Kirigami-inspired cuts are patterned on the foam to provide the drape necessary for mimicking the performance of textile and close to body materials. In total, nine different configurations, three different fill factors and three different Kirigami cut patterns were fabricated and inspected for thermal characterization, mechanical testing, flexibility and drape. Our studies show that adding Kirigami patterns can increase the durability of the device, improve the flexibility, decrease the drape coefficient, and have <1% of impact on cooling performance at higher fill factors (>1.5%), reaching temperature differences up to 4.39 ± 0.17°C between the hot and cold faces of the device. These thermoelectric cooling devices show great flexibility, durability, and cooling for integration into soft cooling products.

An Algorithm to Calibrate and Correct the Response to Unpolarized Radiation of the X-Ray Polarimeter Onboard IXPE

The Gas Pixel Detector (GPD) is an X-ray polarimeter to fly onboard IXPE and other missions. To correctly measure the source polarization, the response of IXPE’s GPDs to unpolarized radiation has to be calibrated and corrected. In this paper, we describe the way such response is measured with laboratory sources and the algorithm to apply such correction to the observations of celestial sources. The latter allows to correct the response to polarization of single photons, therefore allowing great flexibility in all the subsequent analysis. Our correction approach is tested against both monochromatic and nonmonochromatic laboratory sources and with simulations, finding that it correctly retrieves the polarization up to the statistical limits of the planned IXPE observations.

Investigating the Use of Task Resumption Cues to Support Learning in Interruption-Prone Environments

The ubiquity of mobile devices in peoples’ everyday life makes them a feasible tool for language learning. Learning anytime and anywhere creates great flexibility but comes with the inherent risk of infrequent learning and learning in interruption-prone environments. No matter the length of the learning break, it can negatively affect knowledge consolidation and recall. This work presents the design and implementation of memory cues to support task resumption in mobile language learning applications and two evaluations to assess their impact on user experience. An initial laboratory experiment (N=15) revealed that while the presentation of the cues had no significant effect on objective performance measures (task completion time and error rate), the users still perceived the cues as helpful and would appreciate them in a mobile learning app. A follow-up study (N=16) investigated revised cue designs in a real-world field setting and found that users particularly appreciated our interactive test cue design. We discuss strengths and limitations of our concept and implications for the application of task resumption cues beyond the scope of mobile language learning.

An SDN-Based Solution for Horizontal Auto-Scaling and Load Balancing of Transparent VNF Clusters

This paper studies the problem of the dynamic scaling and load balancing of transparent virtualized network functions (VNFs). It analyzes different particularities of this problem, such as loop avoidance when performing scaling-out actions, and bidirectional flow affinity. To address this problem, a software-defined networking (SDN)-based solution is implemented consisting of two SDN controllers and two OpenFlow switches (OFSs). In this approach, the SDN controllers run the solution logic (i.e., monitoring, scaling, and load-balancing modules). According to the SDN controllers instructions, the OFSs are responsible for redirecting traffic to and from the VNF clusters (i.e., load-balancing strategy). Several experiments were conducted to validate the feasibility of this proposed solution on a real testbed. Through connectivity tests, not only could end-to-end (E2E) traffic be successfully achieved through the VNF cluster, but the bidirectional flow affinity strategy was also found to perform well because it could simultaneously create flow rules in both switches. Moreover, the selected CPU-based load-balancing method guaranteed an average imbalance below 10% while ensuring that new incoming traffic was redirected to the least loaded instance without requiring packet modification. Additionally, the designed monitoring function was able to detect failures in the set of active members in near real-time and active new instances in less than a minute. Likewise, the proposed auto-scaling module had a quick response to traffic changes. Our solution showed that the use of SDN controllers along with OFS provides great flexibility to implement different load-balancing, scaling, and monitoring strategies.

Covid-19 crisis and its impacts on the economic and financial sector

The World Bank data confirm that the recovery scenario will be different depending on the type of nation, the fundamentals of its economy, etc.. The Bank of Italy expects a growth of more than 4% for Italy at the end of 2021. The Italian banking system has shown great flexibility in dealing with the coronavirus emergency, taking a completely different form from the last in 2008 recession, when credit institutions were part of the problem. With their new social role, today in fact they are leading players. The health of the banking sector has also changed compared to 2008, with a stronger capital position, underlying the substantial resilience of the ecosystem and a more advanced expertise in NPL management. The role of the banks operating in Italy has been and will be to support firms, households and the growth of the economy with the sound and prudent distribution of credit, the offer of modern and efficient payment services thanks also to new technologies, business advice to companies for the development and internationalization. A clear evolution is opening up for banks in post-Covid towards digital business with a growing commitment in terms of investments in information technology.

Survey on Some Optimization Possibilities for Data Plane Applications

By programming both the data plane and the control plane, network operators can customize their networks based on their needs, regardless of the hardware manufacturer. Control plane programming, a major component of the SDN (Software Defined Network) concept, has been developed for more than 10 years and successfully implemented in real networks. Efforts to develop reconfigurable data planes and high-level network programming languages make it truly possible to program data planes. Therefore, the programmable data planes and SDNs offer great flexibility in network customization, allowing many innovations to be introduced on the network. The general focus of research on the data plane is data-plane abstractions, languages and compilers, data plane algorithms, and applications. This paper outlines some emerging applications on the data plane and offers opportunities for further improvement and optimization.

Flexible Theoretical Calculation of Loop Length and Area Density of Weft-Knitted Structures: Part II

A simple and flexible method for theoretical calculation of the main structural parameters of various weft-knitted fancy and combined patterns is presented in this article. It is especially important for patterns containing different elements, such as loops, floats of different lengths, tucks, and tuck stitches. Measurement of an actual average length of the loop in these fabrics is complicated because it is necessary to disassemble precisely one pattern repeat to measure the yarn length and divide it by the number of elements in this pattern repeat. For large and complex pattern repeats, this is difficult and usually gives a high number of errors. It is very important to have lengths of structural elements as it helps to predict the main physical properties of knitted fabrics and their mechanical behaviour, which is especially important for protective textiles. The main idea of the proposed method, based on Čiukas geometrical model, is to calculate lengths of various structural elements or even their parts separately, taking into account the number of needle bars and their formation principle, which gives great flexibility to such modelling. The proposed theoretical formulas can be used for various patterned weft-knitted structures containing not only loops but tucks, floats of different lengths, or additional yarns; they give very few errors in empirical calculations and are easy to use.

ISLAMIC BANKING MARKET DISCIPLINE IN INDONESIA

This paper examines the market discipline of Islamic banks, as manifested by the responses of depositors with regard to their deposits and profit-sharing ratio to the fundamentals of the banks in the case of Indonesia. We analyse the supply and demand function of deposits using panel data from 10 Islamic banks from 2010 Q1 to 2019 Q4. We empirically find that market discipline in Indonesian Islamic banks is relatively weak, and conjecture that this is for two reasons. First, religious depositors have driven the unusual behaviour of Islamic banks, as we find that they stay with the same bank, even if it has poor fundamental conditions. Second, the profit and loss sharing mechanism means that Islamic bank depositors do not have great flexibility in demanding a higher rate relevant to the risk they must bear. This is because depositors' actual return is set to be consistent with the actual profit obtained from the banks' lending activities. Our results lead to the call for policymakers to effectively monitor the fundamental conditions of Islamic banks and to collaborate with agencies and organisations that promote Islamic bank development in Indonesia.

Grasp Point Optimization and Leakage-Compliant Dimensioning of Energy-Efficient Vacuum-Based Gripping Systems

Vacuum-based handling, used in many applications and industries, offers great flexibility and fast handling processes. However, due to significant energy conversion losses from electrical energy to the useable suction flow, vacuum-based handling is highly energy-inefficient. In preliminary work, we showed that our grasp optimization method offers the potential to save at least 50% of energy by a targeted placement of individual suction cups on the part to be handled. By considering the leakage between gripper and object, this paper aims to extend the grasp optimization method by predicting the effective compressed air consumption depending on object surface roughness, gripper diameter and gripper count. Through balancing of the target pressure difference and the leakage tolerance in combination with the gripper count and gripper diameter, significant reductions of the compressed air, use and therefore the overall energy consumption, can be achieved. With knowledge about the gripper-specific leakage behavior, in the future it will be straightforward for system integrators to minimize the need for oversizing due to process-related uncertainties and therefore to provide application-specific and energy-optimized handling solutions to their customers.