P8.4 - Switching-Type Lambda Sensor Manufactured by Joining of Sintered Zirconia via Glass Solder Paste

This study considers the problem of energetical efficiency in switching type sliding mode control of discrete-time systems. The aim of this work is to reduce the quasi-sliding mode band-width and, as follows, the necessary control input, through an application of a new type of time-varying sliding hyperplane in quasi-sliding mode control of sampled time systems. Although time-varying sliding hyperplanes are well known to provide insensitivity to matched external disturbances and uncertainties of the model in the whole range of motion for continuous-time systems, their application in the discrete-time case has never been studied in detail. Therefore, this paper proposes a sliding surface, which crosses the system’s representative point at the initial step and then shifts in the state space according to the pre-generated demand profile of the sliding variable. Next, a controller for a real perturbed plant is designed so that it drives the system’s representative point to its reference position on the sliding plane in each step. Therefore, the impact of external disturbances on the system’s trajectory is minimized, which leads to a reduction of the necessary control effort. Moreover, thanks to a new reaching law applied in the reference profile generator, the sliding surface shift in each step is strictly limited and a switching type of motion occurs. Finally, under the assumption of boundedness and smoothness of continuous-time disturbance, a compensation scheme is added. It is proved that this control strategy reduces the quasi-sliding mode band-width from O(T) to O(T3) order from the very beginning of the regulation process. Moreover, it is shown that the maximum state variable errors become of O(T3) order as well. These achievements directly reduce the energy consumption in the closed-loop system, which is nowadays one of the crucial factors in control engineering.

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Improved Synaptic Device Properties of HfAlOx Dielectric on Highly Doped Silicon Substrate by Partial Reset Process

Metals ◽

10.3390/met11050772 ◽

2021 ◽

Vol 11 (5) ◽

pp. 772

Author(s):

Seunghyun Kim ◽

Osung Kwon ◽

Hojeong Ryu ◽

Sungjun Kim

Keyword(s):

Resistive Switching ◽

Silicon Substrate ◽

Photoelectron Spectroscopy ◽

Random Access ◽

Resistive Random Access Memory ◽

Alloy Type ◽

Switching Type ◽

Neuromorphic System ◽

Device Properties ◽

Partial Reset

This work demonstrates the synaptic properties of the alloy-type resistive random-access memory (RRAM). We fabricated the HfAlOx-based RRAM for a synaptic device in a neuromorphic system. The deposition of the HfAlOx film on the silicon substrate was verified by X-ray photoelectron spectroscopy (XPS) analysis. It was found that both abrupt and gradual resistive switching could be implemented, depending on the reset stop voltage. In the reset process, the current gradually decreased at weak voltage, and at strong voltage, it tended to decrease rapidly by Joule heating. The type of switching determined by the first reset process was subsequently demonstrated to be stable switching by successive set and reset processes. A gradual switching type has a much smaller on/off window than abrupt switching. In addition, retention maintained stability up to 2000 s in both switching cases. Next, the multiple current states were tested in the gradual switching case by identical pulses. Finally, we demonstrated the potentiation and depression of the Cu/HfAlOx/Si device as a synapse in an artificial neural network and confirmed that gradual resistive switching was suitable for artificial synapses, using neuromorphic system simulation.

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Functional and sociocultural attitudes of code-switching and its relation to the meaning-making process: The case of dubbing Kim Possible into Arabic

International Journal of Bilingualism ◽

10.1177/13670069211019482 ◽

2021 ◽

pp. 136700692110194

Author(s):

Rashid Yahiaoui ◽

Marwa J Aldous ◽

Ashraf Fattah

Keyword(s):

Meaning Making ◽

Code Switching ◽

Power Dynamics ◽

Sociocultural Attitudes ◽

Switching Patterns ◽

Switching Functions ◽

Switching Type ◽

Lebanese Arabic ◽

Research Questions

Aims and objectives/purpose/research questions: The aim of this study is to investigate the sociolinguistic functions of code-switching and its relation to the meaning-making process by using the animated series Kim Possible as a case study. Design/methodology/approach: This study employs Muysken’s taxonomy to draw on code-switching patterns in lexico-grammar in relation to human behavior. The study also uses the functional approaches of Muysken and Appel and Gumperz as binary investigatory frameworks to locate interlingual and intralingual code-switching particularities and to elaborate on code-switching functions. Data and analysis: The analysis encompasses 48 episodes. Firstly, we extracted and transcribed code-switching occurrences in light of Muysken’s typology episode-by-episode and categorized them according to their code-switching type (interlingual or intralingual). Secondly, we quantified the occurrences according to their syntactic form to make more systematic claims about code-switching patterns. Next, we triangulated the patterns by examining the context of utterances and extralinguistic factors in the original series vis-à-vis the dubbed version to draw upon information beyond the structure or grammar. Findings/conclusions: The Arabic dubbed version was able to communicate the characters’ cosmopolitan diversity, which correlates with the series’ sense of linguistic modernity and humor. At the same time, the Arabic version was able to portray the extralinguistic reality of Lebanon and its multi-linguistic tapestry. Originality: This research is original because it focuses on Lebanese-Arabic, a dialect seldom discussed in the context of translation. The research also examines language variations in the context of dubbed discourse, where code-switching is integrally pertinent to visual-signs and the cultural background of characters. Significance/implications: The study recognizes the intricacy of code-switching as a reflective phenomenon of social reality and power dynamics; therefore, it contributes in the fields of translation and sociolinguistics.

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Study on the Reliability of Sn–Bi Composite Solder Pastes with Thermosetting Epoxy under Thermal Cycling and Humidity Treatment

Crystals ◽

10.3390/cryst11070733 ◽

2021 ◽

Vol 11 (7) ◽

pp. 733

Author(s):

Lu Liu ◽

Songbai Xue ◽

Ruiyang Ni ◽

Peng Zhang ◽

Jie Wu

Keyword(s):

Solder Joint ◽

Thermal Cycling ◽

Composite Solder ◽

Solder Joints ◽

Solder Paste ◽

Epoxy System ◽

Mechanical Reinforcement ◽

Microstructure Observation ◽

Temperature And Humidity ◽

Thermosetting Epoxy

In this study, a Sn–Bi composite solder paste with thermosetting epoxy (TSEP Sn–Bi) was prepared by mixing Sn–Bi solder powder, flux, and epoxy system. The melting characteristics of the Sn–Bi solder alloy and the curing reaction of the epoxy system were measured by differential scanning calorimeter (DSC). A reflow profile was optimized based on the Sn–Bi reflow profile, and the Organic Solderability Preservative (OSP) Cu pad mounted 0603 chip resistor was chosen to reflow soldering and to prepare samples of the corresponding joint. The high temperature and humidity reliability of the solder joints at 85 °C/85% RH (Relative Humidity) for 1000 h and the thermal cycle reliability of the solder joints from −40 °C to 125 °C for 1000 cycles were investigated. Compared to the Sn–Bi solder joint, the TSEP Sn–Bi solder joints had increased reliability. The microstructure observation shows that the epoxy resin curing process did not affect the transformation of the microstructure. The shear force of the TSEP Sn–Bi solder joints after 1000 cycles of thermal cycling test was 1.23–1.35 times higher than the Sn–Bi solder joint and after 1000 h of temperature and humidity tests was 1.14–1.27 times higher than the Sn–Bi solder joint. The fracture analysis indicated that the cured cover layer could still have a mechanical reinforcement to the TSEP Sn–Bi solder joints after these reliability tests.

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Eco-Friendly Lead-Free Solder Paste Printing via Laser-Induced Forward Transfer for the Assembly of Ultra-Fine Pitch Electronic Components

Materials ◽

10.3390/ma14123353 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3353

Author(s):

Marina Makrygianni ◽

Filimon Zacharatos ◽

Kostas Andritsos ◽

Ioannis Theodorakos ◽

Dimitris Reppas ◽

...

Keyword(s):

High Resolution ◽

Form Factors ◽

Circuit Board ◽

Lead Free ◽

Process Conditions ◽

Solder Paste ◽

Electronic Components ◽

Successful Operation ◽

Fine Pitch ◽

Forward Transfer

Current challenges in printed circuit board (PCB) assembly require high-resolution deposition of ultra-fine pitch components (<0.3 mm and <60 μm respectively), high throughput and compatibility with flexible substrates, which are poorly met by the conventional deposition techniques (e.g., stencil printing). Laser-Induced Forward Transfer (LIFT) constitutes an excellent alternative for assembly of electronic components: it is fully compatible with lead-free soldering materials and offers high-resolution printing of solder paste bumps (<60 μm) and throughput (up to 10,000 pads/s). In this work, the laser-process conditions which allow control over the transfer of solder paste bumps and arrays, with form factors in line with the features of fine pitch PCBs, are investigated. The study of solder paste as a function of donor/receiver gap confirmed that controllable printing of bumps containing many microparticles is feasible for a gap < 100 μm from a donor layer thickness set at 100 and 150 μm. The transfer of solder bumps with resolution < 100 μm and solder micropatterns on different substrates, including PCB and silver pads, have been achieved. Finally, the successful operation of a LED interconnected to a pin connector bonded to a laser-printed solder micro-pattern was demonstrated.

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