Internal Circuit Research Articles

(Digital Presentation) Electrothermal Modeling of Interfacial Phase Change Memory

Phase change memory (PCM) is a high-speed non-volatile memory that utilizes the reversible and fast transition between highly conductive crystalline phase and highly resistive (dielectric) amorphous phase of the phase change material to store information and the large electrical resistivity contrast between the two phases for retrieval of the stored data [1,2]. One of the main challenges for PCM is the large power required to heat the active region above crystallization or melting temperature. Lower energy and higher speed operations have been demonstrated with thin film superlattice stacks of phase change materials known as interfacial phase change memory (iPCM) [3-6]. The mechanisms behind the improved performance of iPCM are still under investigation but recent work indicates similar crystallization and melt-quench operation of these devices [5].In this work, we perform electrothermal finite element simulations of reset and set operations on iPCM structures consisting of alternately stacked Ge2Sb2Te5 (GST) and GeTe layers using COMSOL multiphysics [7-10]. Electrical pulses are applied for reset and set processes utilizing an internal circuit model where a transistor is used as an access device. Coupled electric current and heat transfer physics are employed to incorporate Joule heating and thermoelectric effects (Thomson heat within a single material and Peltier heat at material interfaces) with temperature dependent Seebeck coefficients, thermal conductivities, electrical resistivities, heat capacities and thermal boundary resistances (TBR) for each material / material pairs. Latent heat of fusion is included in the amorphous-crystalline and solid-liquid transitions [10], giving rise to heat release at the crystal-amorphous boundaries during crystal growth and heat absorption at the grain boundaries during amorphization. Grain boundaries and material interfaces have high energy sites, making them easier to melt, described as heterogeneous melting [10].iPCM [5] structures utilize engineered interfaces formed between nanometer scale thin-film stacks, promoting amorphization through increased number of material interfaces and reduced thermal conduction due to TBR. Furthermore, the melting temperature, electrical conductivity and Seebeck coefficient of the different materials within an iPCM device differ. Hence, such layered structures may have the advantage of melting of only one of the alternating layers assisted by local heating or cooling due to Peltier effect at the interfaces.Our results on iPCM and conventional PCM structures of same dimensions and geometry (20 nm wide, 150 nm high pore-cells) show ~ 50% reduction in reset times and more consistent set times for iPCM cells due to lesser variations in grain sizes and location of boundaries.Acknowledgment: This work is partially supported by the National Science Foundation under award DMR-1710468.

RASCv2: Enabling Remote Access to Side-Channels for Mission Critical and IoT Systems

The Internet of Things (IoT) and smart devices are currently being deployed in systems such as autonomous vehicles and medical monitoring devices. The introduction of IoT devices into these systems enables network connectivity for data transfer, cloud support, and more, but can also lead to malware injection. Since many IoT devices operate in remote environments, it is also difficult to protect them from physical tampering. Conventional protection approaches rely on software. However, these can be circumvented by the moving target nature of malware or through hardware attacks. Alternatively, insertion of the internal monitoring circuits into IoT chips requires a design trade-off, balancing the requirements of the monitoring circuit and the main circuit. A very promising approach to detecting anomalous behavior in the IoT and other embedded systems is side-channel analysis. To date, however, this can be performed only before deployment due to the cost and size of side-channel setups (e.g., and oscilloscopes, probes) or by internal performance counters. Here, we introduce an external monitoring printed circuit board (PCB) named RASC to provide r emote a ccess to s ide- c hannels. RASC reduces the complete side-channel analysis system into two small PCBs (2 \( \times \) 2 cm), providing the ability to monitor power and electromagnetic (EM) traces of the target device. Additionally, RASC can transmit data and/or alerts of anomalous activities detected to a remote host through Bluetooth. To demonstrate RASCs capabilities, we extract keys from encryption modules such as AES implemented on Arduino and FPGA boards. To illustrate RASC’s defensive capabilities, we also use it to perform malware detection. RASC’s success in power analysis is comparable to an oscilloscope/probe setup but is lightweight and two orders of magnitude cheaper.

Development of a low-cost IoT system based on LoRaWAN for monitoring variables related to electrical energy consumption in low voltage networks

Energy efficiency is an issue that is currently gaining relevance, high electricity demands worldwide generate a negative impact on the planet caused by the natural depletion of resources associated with production processes. In this regard, the technologies associated with the Internet of Things (IoT) are considered as a tool to optimize processes and resources through the monitoring of variables. In this context, this work proposes a low-cost electronic system with IoT architecture used in the monitoring of electrical variables, this becomes a support tool in the estimation of energy consumption in internal distribution electrical circuits of homes or small industries. This device generates information to recognize consumption patterns and load balances per electrical phase, contains two hardware modules and a software user interface. The first is an electronic node that includes a high-performance polyphase meter based on the Atmel M90E32AS chip, which is controlled by an ESP32 chip, for wireless communication is used a Radio Frequency (RF) module in the 915 MHz band and LoRa protocol based on the Semtech SX1278 transceiver, this node is able to measure and transmit variables such as current, voltage, active energy, reactive energy, power factor and other electrical variables in circuits of up to three phases. For the study, a calibration process was carried out in an accredited laboratory (Metrex S.A. in Colombia), then tests were performed by monitoring a three-phase 110V electrical circuit in a small factory, with the information generated it was possible to identify consumption patterns over a period of seven consecutive days, important data such as times when energy is wasted due to improper use of loads connected to the network, electric stoves, computer equipment turned on during non-working hours are examples of the results obtained.

중급상담자의 의미 있는 관계 경험과 개인적 성장에 관한 현상학적 연구

Objectives This study was conducted to reveal the essence of meaningful relationship experiences experienced in real life and the personal growth experiences of intermediate counselors. Methods By applying Giorgi's phenomenological research method as a research method, in-depth interviews and data analysis were conducted on eight intermediate counselors with more than 4 years of counseling experience. Results As a result, 114 semantic units, 30 sub-themes, and 10 upper-level topics were found. The top 10 topics are as follows: “Struggling in a shallow and superficial relationship,” “Family relationships are the most lively, rawest relationship learning laboratory,” “Training yourself in a sense of stability from being understood and accepted,” “Bringing yourself together with various relationships you've met at the counseling site,” “Building a life of self-esteem,” and “Restructuring your perspective of yourself and others,” “Treating yourself and others with a warm heart,” “Establishing proper attitude of a counselor,” “Building sincere relationships with clients,” “Learning the internal circuit for building relationships that save lives”. Conclusions This study is significant in that it specifically presented the meaningful relationship experiences experienced by intermediate counselors in real life with an in-depth examination method and explored in detail how it is expressed in the counselor's personal growth. In addition, not only improving professional qualities through counseling practice and theoretical education, this study can be used as a material to educate counselors the significance of counselors’ personal qualities as an instrument for counseling practice and encourage them to work on real-life relationship experiences for personal growth.

Research on dual antenna design of RFID sensor

With the popularization and application of RFID sensors, the energy supply of internal circuits is a key problem. When multiple monitoring quantities are involved, the traditional energy extraction method of RFID sensors often leads to insufficient energy. Therefore, this paper designs an RFID sensor integrating acceleration and temperature sensing parameters, and proposes a cross placed dual antenna scheme. In order to increase the concentration of antenna radiation energy, a metal reflective aluminum plate is added. Through experimental tests, it is proved that the scheme can well optimize the radiation direction and performance of the antenna.

Quantitative Analysis of Internet of Things Technology on the National Economic Accounting: A Prediction Model Based on the FCM-BP Neural Network Algorithm.

The development of Internet of Things (IoT) technology is of great significance for modern financial settlements based on information technology. The IoT technology, which can provide a convenient approach for accounting, has the advantages of intelligent processing, reliable transmission, and comprehensive perception. For national economic accounting, a new integrated system for monitoring the environment is developed and designed by using embedded development technology and sensor technology. The system uses a wireless sensor network environment monitoring system IoT platform with embedded internal processors. Analyze and design the system as a whole, including the construction of the basic platform of the system, the design of the internal plates and circuits of the system, the monitoring design of the input node, and the monthly design of the output interface calculation. Finally, a physical model is built, and data measurement and analysis are carried out under different conditions, and the evaluation and advantage analysis of the system's operating status are given. The system can carry out all-round, multilevel and three-dimensional real-time monitoring of the construction site environment, including dust, PM2.5, temperature, humidity, wind speed, carbon dioxide, and other indicators in the construction site environment. In addition, the system can upload various monitoring data to the detection system through the internal network. The system has the functions of monitoring, alarming, recording, querying, and counting of the target monitoring station and can also be linked with the environmental control device. The construction site staff can conduct real-time supervision through the mobile terminal and computer terminal management platform. In addition, it can also meet the role of real-time remote monitoring and online guidance and regulation. It has reference value for the safety and management of the actual operation process of the project.

О некоторых проблемах автоматизации управления в высших учебных заведениях

The article discusses the issues of automating the management of a higher educational institution and possible ways to solve them. The subject of research in this article is the regularities of higher educational institution management, which should be taken into account when building automated higher educational institution management systems. The purpose of the study is to consider the features of the laws governing the management of a higher educational institution and their consideration in the construction of automated control systems for a higher educational institution. As research methods, a systematic approach, analysis, synthesis, induction, deduction, abstraction, generalization, and a method of modeling managerial situations were used. In the chord of the study, the following was found. There are two approaches to automating the management of higher education institutions: an approach to automating management based on standard solutions in the field of automation of management, and an approach based on individual solutions in the field of automating the management of higher education institutions. An analysis of these approaches shows that in order to improve the efficiency of managing higher education institutions, it is necessary to use a two-loop scheme of management automation. At the same time, a typical solution should be used as an external loop for automating the management of higher education institutions, while an individual solution in the field of automating the management of a higher education institution should be used as an internal loop for automating the management of higher education institutions. At the same time, in order to ensure the effectiveness of the interaction between the internal and external circuits of automation of the management of higher educational institutions, they must be harmonized with each other.

Development of crypto-code constructs based on LDPC codes

The results of developing post-quantum algorithms of McEliece and Niederreiter crypto-code constructs based on LDPC (Low-Density Parity-Check) codes are presented. With the rapid growth of computing capabilities of mobile technologies and the creation of wireless mesh and sensor networks, Internet of Things technologies, and smart technologies on their basis, information security is becoming an urgent problem. At the same time, there is a need to consider security in two circuits, internal (directly within the network infrastructure) and external (cloud technologies). In such conditions, it is necessary to integrate threats to both the internal and external security circuits. This allows you to take into account not only the hybridity and synergy of modern targeted threats, but also the level of significance (degree of secrecy) of information flows and information circulating in both the internal and external security circuits. The concept of building security based on two circuits is proposed. To ensure the security of wireless mobile channels, it is proposed to use McEliece and Niederreiter crypto-code constructs based on LDPC codes, which allows integration into the credibility technology of IEEE 802.15.4, IEEE 802.16 standards. This approach provides the required level of security services (confidentiality, integrity, authenticity) in a full-scale quantum computer. Practical security technologies based on the proposed crypto-code constructs, online IP telephony and the Smart Home system based on the use of an internal server are considered

Translated article] Position statement relating ankle fractures in major outpatient surgery

IntroductionThe increase in the prevalence of osteoporosis associated with ageing, and sports and traffic accidents, are responsible for the increase in ankle fractures. This fact emphasises the need to protocolise their care in order to provide greater clinical benefit to patients, and better cost–benefit ratios to the health system. Aim and methodAt present, there is no common framework for implementation of protocols and internal circuits of the Spanish centres for ankle fractures by means of major outpatient surgery (MOS), which is the final objective of this position paper. For this, the clinical and economic evidence of MOS, the local environment and the strategies for its implementation are reviewed, related to ankle fractures. Clinical and economic evidenceThe results showed a better cost–benefit ratio in outpatients compared to traditional hospitalisation, with lower complications and readmission rates and therefore significant cost savings. Barriers and strategiesGeneral and specific barriers are reviewed, as well as strategies and circuits for proper implementation. ResultsThe results show lower complication and readmission rates together with significant cost savings. It entails a better cost–benefit ratio in outpatient care compared to traditional hospitalisation. Position statementThe implementation of MOS contributes to improve the quality of care, and the satisfaction of both, patient and health care team, while optimising the utilisation of resources. Ankle fractures in patients selected for both the underlying pathology, anaesthetic risk, and the type of fracture can be operated satisfactorily under the MOS.

A dynamic air–liquid interface system for in vitro mimicking of the nasal mucosa

The development of an in vitro 3D model for the growth of the nasal mucosa cells can improve the therapy and the study of pathological states for subjects with chronic airway conditions. We have previously characterized a system consisting of a scaffold with an internal channel and a perfusion bioreactor with two independent flows provided by an external and an internal circuit, respectively. In this paper, this system was designed as a model of the nasal cavity, in which cells, grown on the inner surface of the scaffold channel, would be in contact at the same time with both culture medium, supplied by the external circuit, and air, provided with the internal flow. To ensure adequate nutrient supply to the cells in the scaffold channel, the radial diffusion of the culture medium through the porous matrix was evaluated first in qualitative and, then, in quantitative terms, demonstrating the capability of the system to control the value and direction of this flux. As a preliminary study, the culture of epithelial cells in the scaffold channel is also discussed in static, maintaining the air-liquid interface condition for up to 3 weeks. Despite minor abnormalities, such as a gap between cell layers and some detachments from the scaffold, the scaffold ensured cell survival and growth during the experimental time.

Design of Building Environment Detection System for Architectures Based on Internet of Things.

In the process of urban building design, a new integrated system for monitoring the environment is developed and designed by using embedded development technology and sensor technology. The system uses a wireless sensor network environment monitoring system IoT platform with embedded internal processors. Analyze and design the system as a whole, including the construction of the basic platform of the system, the design of the internal plates and circuits of the system, the monitoring design of the input node, and the monthly design of the output interface calculation. Finally, a physical model is built, and data measurement and analysis are carried out under different conditions, and the evaluation and advantage analysis of the system's operating status are given. The system can carry out all-round, multilevel, and three-dimensional real-time monitoring of the construction site environment, including dust, PM2.5, temperature, humidity, wind speed, carbon dioxide, and other indicators in the construction site environment. In addition, the system can upload various monitoring data to the detection system through the internal network. The system has the functions of monitoring, alarming, recording, querying, and counting of the target monitoring station and can also be linked with the environmental control device. The construction site staff can conduct real-time supervision through the mobile terminal and computer terminal management platform. In addition, it can also meet the role of real-time remote monitoring and online guidance and regulation. It has reference value for the safety and management of the actual operation process of the project.

Differential signal balancer embedded in silicon LSI as smallest common-mode filter combined bifilar coupling inductors and stacked delay lines

The new differential signal balancer embedded in the metal wiring layer of silicon LSI having increased wiring density and improved characteristics is developed. An internal delay line circuit is stacked vertically to obtain a larger delay time than the extended horizontally structure, and the two inductors for common-mode noise rejection are configured with a stacked bifilar winding structure to obtain higher effective coupling and lower parasitic resistance. Compared to the previous design, the common-mode rejection ratios at 2.4 GHz and 5.4 GHz have been improved by 4.0 dB and 4.6 dB in a smaller area of 120 × 230 μm2, respectively.

Thermal Simulation Analysis of Internal Control Circuit Board of Steering Gear Box Based on COMSOL Three-Dimensional Simulation Software.

The steering gear device includes two parts, a steering gear control circuit and a transmission component. The transmission component includes a ball screw and a motor. During the operation of the steering gear, due to the presence of the steering gear ball screw motor and friction, a certain amount of heat will be generated, which will affect the steering gear control circuit in a confined space. At the same time, the steering gear is inevitable in the actual working process, and will experience a high temperature environment, which will increase the temperature of the internal structure of the steering gear, and due to the difference in thermal expansion coefficients between various materials, stress and strain will occur in the structure, which may cause mismatch or even cracks in the system structure, and the steering gear system cannot work normally. It is necessary to analyze the thermal characteristics of the overall steering gear under multiple factors. Based on this, this paper uses COMSOL three-dimensional simulation software to conduct thermal simulation analysis on the shell of the steering gear containing the control circuit board. The temperature distribution and stress-strain response law of the control circuit board in the box, and the influence of different materials and thickness of the box heat insulation layer on the thermal characteristics of the control circuit are discussed, and then a reasonable thickness and material of the heat insulation layer are obtained for the design of the rudder chassis for reference.

Documento de posicionamiento respecto a las fracturas de tobillo en cirugía mayor ambulatoria

IntroductionThe increase in the prevalence of osteoporosis associated with ageing, and sports and traffic accidents, are responsible for the increase in ankle fractures. This fact emphasises the need to protocolise their care in order to provide greater clinical benefit to patients, and better cost–benefit ratios to the health system. Aim and methodAt present, there is no common framework for implementation of protocols and internal circuits of the Spanish centres for ankle fractures by means of major outpatient surgery (MOS), which is the final objective of this position paper. For this, the clinical and economic evidence of MOS, the local environment and the strategies for its implementation are reviewed, related to ankle fractures. Clinical and economic evidenceThe results showed a better cost–benefit ratio in outpatients compared to traditional hospitalisation, with lower complications and readmission rates and therefore significant cost savings. Barriers and strategiesGeneral and specific barriers are reviewed, as well as strategies and circuits for proper implementation. ResultsThe results show lower complication and readmission rates together with significant cost savings. It entails a better cost–benefit ratio in outpatient care compared to traditional hospitalisation. Position statementThe implementation of MOS contributes to improve the quality of care, and the satisfaction of both, patient and health care team, while optimising the utilisation of resources. Ankle fractures in patients selected for both the underlying pathology, anaesthetic risk, and the type of fracture can be operated satisfactorily under the MOS.

Self-Powered and Flexible Triboelectric Sensors with Oblique Morphology towards Smart Swallowing Rehabilitation Monitoring System.

With aging, disability of the body can easily occur because the function of the body is degraded. Especially, swallowing disorder is regarded as a crucial issue because patients cannot obtain the nutrients from food by swallowing it. Hence, the rehabilitation of swallowing disorder is urgently required. However, the conventional device for swallowing rehabilitation has shown some limitations due to its external power source and internal circuit. Herein, a self-powered triboelectric nanogenerator for swallowing rehabilitation (TSR) is proposed. To increase the electrical output and pressure sensitivity of the TSR, the tilted reactive ion etching is conducted and the electrical output and pressure sensitivity are increased by 206% and 370%, respectively. The effect of the tilted reactive ion etching into the electrical output generated from the TSR is systematically analyzed. When the tongue is pressing, licking, and holding the TSR, each motion is successfully detected through the proposed TSR. Based on these results, the smart swallowing rehabilitation monitoring system (SSRMS) is implemented as the application and the SSRMS could successfully detect the pressing by the tongue. Considering these results, the SSRMS can be expected to be utilized as a promising smart swallowing rehabilitation monitoring system in near future.

A novel analog controller design scheme for LLC resonant converter used in battery charging application

A new generation of batteries must be charged according to the charging curves recommended by battery manufacturers. For high reliability, low cost, high speed, and pulse by pulse protection ability, the controller of these chargers are commonly designed by analog circuits. Analog controllers can be implemented by internal circuits of analog controller ICs with additional passive elements. This paper proposes a controller design approach for battery charger applications with an LLC converter. The proposed approach stands on a novel method for applying the well-known least-squares (LS) identification method for designing the classic controller with changing the identification problem to the design problem. Compared with other methods, the proposed approach benefits from design a controller with desired structure and desired performance, simultaneously. Here, modelling of LLC converter has been carried out by the first harmonic approximation (FHA) method. For controller design, the linear model has been extracted by linearizing the non-linear FHA model. In addition, for providing the reduced switching losses and increased efficiency, the passive elements of the resonance tank and isolation transformer ratio have been designed to operate the converter in the zero-voltage switching (ZVS) region. To verify the controller and designed converter, some simulation and experimental results are provided.

Radiation effect on the polymer-based capacitive relative humidity sensors

The sensitivity of polymer-based capacitive relative humidity (RH) sensors after irradiation with neutrons, electrons and protons was measured. Degradation consists of the decreasing of the upper RH limit that can be measured. At the same time, low RH-level sensitivity is almost stable. After 30 krad of absorption dose, RH cut off is equal to 85% of max value, after 60 krad–40%. Degradation reduces after annealing which indicates high radiation sensitivity of the internal circuit in comparison to RH-sensing polymer film.

Induction motor with rotor circuit with pulse-and-switch control for mining machines

Regarding the cyclic mechanisms of mining machines, it is proposed to improve induction motors by adding them with pulse-and-switch control using the power switches GTO, IGBT and MOSFET with the update control circuits. The motors of mining machines down to date use the relay–contact resistance control based on the induction motor with phase-wound rotor. This article discusses the advanced and relatively simple variant of modernization of such induction motors. The computer-aided simulation model is designed and described. The simulation results allow drawing a conclusion that the dualcircuit system with the internal relay circuit of rectified rotor current and the external circuit of velocity at proportional control and PI regulators ensures good performance both in statics and dynamics at simple drive circuit. Modeling was undertaken to compare the dynamics and power performance of the proposed induction motor with vector control and direct orientation in the rotor field. The comparison proves similarity of transient processes with respect to smooth components of mechanical coordinates. The economic effect of the proposed system with the pulse-and-switch control at total re-equipment of the obsolete drives and their replacement by the frequency-variable drives, with all required components and at ‘gentle’ modernization, with substitution of the frequency converter by the new variant proposed in this article while the existing motor with the phase rotor is left. The comparison proves the competitiveness of the proposed variant of induction motor with simpler devices. This study may be useful to design or update induction motors with pulse-and-switch control.The study was supported by the government, Project No. FSWF-2020-0019.

Prediction of Internal Circuit and Mechanical-Electrical-Thermal Response of Lithium-Ion Battery Cell with Mechanical-Thermal Coupled Analysis

The lithium-ion battery (LIB) is widely used as an energy storage device for electric vehicles (EV) due to its advantages, such as high energy density and long lifespan. However, LIB for EV can be exposed to mechanical abuse such as vehicle collision, which causes thermal runaway due to extreme mechanical deformation. Therefore, it is necessary to predict the internal short circuit (ISC) of the LIB cell under mechanical loading conditions and to analyze the mechanical, electrical, and thermal responses after ISC. In this paper, the starting point of ISC is predicted using a two-way mechanical-electrical-thermal coupled analysis method. At the same time, mechanical responses, along with the effects of the ISC area on electrical and thermal responses of the LIB cell, were analyzed. ISC was defined as failure of the separator. The separator’s failure was calculated considering material nonlinearity. Considering the indentation test results, the finite element method (FEM) analysis could accurately predict the starting point of ISC. In the order of cylindrical, hemispherical, and conical indenters, ISC occurred quickly, and the ISC area was large. The larger the ISC area, the greater the voltage drop, current, and joule heat, and the higher the maximum temperature.

Theoretical description and experimental characterization of water content distributions in hydrogen PEM fuel cells

An analytical solution of water mass balance equation was obtained considering diffusion and electroosmotic drag fluxes under non steady state regimes. The theoretical predicted profiles in a membrane electrode assembly were compared experimentally in a single polymer electrolyte hydrogen/oxygen fuel cell changing operating conditions such as, flow velocity, current density and temperature. The specific anodic and cathodic areas were calculated using the carbon monoxide anodic stripping method (ca. 17000 cm2). The electroosmotic drag coefficient was determined with electrochemical isopiestic methods showing temperature invariance, i.e. 2.3 between 313 and 353 K for water contents less than 5, but when reaching 20 it increased to 3.2.Polarization curves were attained galvanodynamically in a single fuel cell showing a strong dependence on water residence (performing with distinct water amounts and conditions). Internal resistance (0.59 to 0.24 Ω cm−2) and open circuit potentials (0.90 to 0.38 V) were affected by water reduction (from 0.8 to 0.4 units). Continuous water recycling of the fuel cell was adopted to preserve the shape and characteristic parameters of the fuel cell under full operation with excellent results.