EMI Environment Research Articles

Electrical design of the flexible imaging diffraction diagnostic for laser experiments (FIDDLE) at the National Ignition Facility (NIF)-Requirements, design, and performance.

The Flexible Imaging Diffraction Diagnostic for Laser Experiments (FIDDLE) is a newly developed diagnostic for imaging time resolved diffraction in experiments at the National Ignition Facility (NIF). It builds on the successes of its predecessor, the Gated Diffraction Development Diagnostic (G3D). The FIDDLE was designed to support eight Daedalus version 2 sensors (six more hCMOS sensors than any other hCMOS-based diagnostic in NIF to date) and an integrated streak camera. We will review the electrical requirements, design, and performance of the electrical subsystems that were created to support this large number of cameras in the FIDDLE. The analysis of the data that the FIDDLE is intended to collect relies heavily on the accurate and well-understood timing of each sensor. We report camera-to-camera timing jitter of less than 100ps rms and sensor integration times of 2.2ns FWHM in 2-2 timing mode. Additionally, diffraction experiments on the NIF produce electric fields (EMI) on the order of 1 kV/m, which have been observed to negatively impact the performance of some electrical components of the FIDDLE. We report on the results of testing hCMOS camera electronics in a similar EMI environment generated in an offline lab. We also summarize the use of a novel approach to using a vector network analyzer as an EMI leak detector to understand and reduce the negative impacts of EMI on the FIDDLE.

Understanding novice Chinese EFL teachers’ beliefs and practice in using English as a medium of instruction

This study explores the beliefs and practices of six novice Chinese EFL teachers in international secondary schools using English as the medium of instruction (EMI). Participants, having overseas educational experiences and an average IELTS score above 6.4, provided insights through semi-structured interviews conducted via WeChat. The findings reveal the complexity and diversity of their beliefs about the role of English and EMI in teaching, shaped by their personal and professional experiences. Challenges faced include large class sizes, limited professional expertise, and varying English proficiency levels among students, which significantly impact their teaching efficacy. The study highlights the need for linguistic support and subject matter expertise to foster EFL teachers’ professional development and enhance EMI teaching efficacy. Implications for pedagogical practices suggest the necessity of supportive measures for novice EFL teachers to navigate the complexities of EMI environments effectively.

The “Multimodal Spiral”: Rethinking the Communication Curriculum at an English as a Medium of Instruction Institution

The rise of English as a Medium of Instruction (EMI) threatens to upend traditional teaching and learning practices. Writing, speaking, and communication instruction will all need to evolve. This article presents a case study of one institution's efforts to design and implement a communication curriculum responsive to the unique demands of the EMI environment. The curriculum proposed enacts an interdisciplinary, multimodal approach to the teaching of communication. We discuss the specifics of the curriculum, the process of its creation, the principles underlying it, and how these principles play out in practice. In doing so, we hope to provide a model both for global communication instruction and future curricular design efforts.

Teaching of Academic Subjects in English and Challenges in English Medium Instruction

Teaching English as a foreign language is an apparently challenging task, especially when it is done in an area where English learn a very slight purpose. This study sought to investigate the challenges of English teaching as well as solutions adopted by English teachers in the Savar area. Moreover, the main objective of this research is to find ou.t what kinds of challenges the teacher community faces in the context of the English teaching infrastructure and how to get rid of those problems. Qualitative methods in a phenomenological approach have been used in the research through which in-depth research has been conducted and data collected through semi-structured interviews using purposive sampling. This study captured the perspective of English teachers in facing the challenges of English teaching in the classroom and the solutions they implemented to solve them through interviews. Participants in the study intended to improve the institution's EMI environment and foster nice interactions between teachers and students. 'Teaching techniques among content teachers,' 'challenges and constraints that content teachers encounter,' and 'Training courses for content teachers' are the primary themes that emerged from the study. To be sustainable, EMI activities incorporate teachers' self-development and institutional support, as well as students' self- and perceived peer learning practices. Students' and teachers' adaptive tactics provide information into how other EMI programs might optimize their deployment.

Language use in an English-medium instruction university in Lebanon

Abstract English-medium instruction (EMI) universities in non-English-dominant contexts often use internationally available tests of English (e.g., TOEFL) and/or locally developed tests to assess the academic English-language proficiency of applicants prior to admission. However, little research has been conducted to establish the extent to which either type of test reflects the real-world classroom discourse, and associated communicative demands, within these often multilingual educational contexts. In this paper, we report on one part of a larger study designed to address this research gap in a particular EMI environment – the American University of Beirut (AUB) in Lebanon. We collected and analysed samples of language use at AUB through non-participant ethnographic observations and video recordings of eight undergraduate classes across academic disciplines. Findings indicated that classes were varied in nature, shifted between registers and levels of interaction, involved a range of translanguaging and English as a Lingua Franca-oriented phenomena, and included meta-commentary about language use. We argue that speaking and listening constructs in English-language admissions tests used in EMI contexts ideally need to be localised or locally developed to best match the unique language use characteristics of these settings.

Exploration on Signal Processing Performance of Wireless Sensor in Electromagnetic Interference Environment

In order to deeply analyze the performance of Electromagnetic Field (EMF) on wireless sensor Signal Processing (SP), this paper first examines the influencing factors of wireless sensor SP performance based on the relevant theories of EMF and wireless sensor. Then, it discusses the influence of EMF on wireless sensor information Transmission and Reception (T & R) time, Package Reception Rate (PRR), and communication throughput. Furthermore, the Packet Loss Rate (PLR) and Bit Error Rate (BER) of the sensor are described, and finally, a conclusion is drawn. The research findings are as follows. This paper makes a statistical study on whether the wireless sensor is disturbed by EMI from three aspects (wireless sensor’s information T & R time, PLR, and communication throughput). In any case, EMF will prolong the wireless sensor’s information T & R time and reduce the PRR and communication throughput. When the distance between the transmitter and the receiver is set to 5 m, the change of field intensity at the transmitter significantly impacts the BER but has little impact on the PLR. However, when the field intensity of the transmitter and the receiver is the same, PLR and BER show no evident difference. Therefore, this paper studies the SP performance of the wireless sensor in the EMI environment, which provides an excellent reference significance for the rapid development of wireless sensors in the future.

The Vital Role of Simulation for Virtual EMI and EMC Test Environments

5G, the internet of things and high-speed wireless communication all require the deployment of microwave and millimetre-wave devices and systems that are optimised for performance. To ensure the operation of these systems and avoid EMI and EMC, designers can turn to virtual test platforms through simulation software.

The Vital Role of Simulation for Virtual EMI and EMC Test Environments

5G, the internet of things and high-speed wireless communication all require the deployment of microwave and millimetre-wave devices and systems that are optimised for performance. To ensure the operation of these systems and avoid EMI and EMC, designers can turn to virtual test platforms through simulation software.

Ultrathin, flexible and sandwich-structured PHBV/silver nanowire films for high-efficiency electromagnetic interference shielding

An ultrathin transparent EMI shielding film with sandwich structure including PHBV, AgNWs and PHBV was fabricated. The AgNW layer encapsulated with PHBV can endow the film with high EMI effectiveness and environment stability.

Toward Successful Implementation of Introductory Integrated Content and Language Classes for EFL Science and Engineering Students

What this research was about and why it is importantIntegrating content and language (ICL) has been a widely applied methodology of language learning and teaching in the last 20 years. However, ICL studies for first‐year undergraduate students of science and engineering are scarce. This study examined perceptions of incoming students and professors who participated in ICL classes at a Korean science and engineering school. Most of the participants found the ICL classes helpful for students to develop a better understanding of content lectures and what to expect in regular content lectures. Also, many students found student‐centered activities, consisting of group work, particularly motivating and effective. The study recommends a formula of ICL instruction for students entering a university with an EMI policy and concludes with suggestions for the successful implementation of ICL classes for content lectures in the areas of science and engineering.What the researchers did This study investigated introductory ICL classes for incoming students at a science and engineering school in Korea. Five introductory ICL classes in the areas of biology, physics, chemistry, programming and mathematics were implemented as part of a three‐week intensive English camp for 121 incoming students. Each ICL class consisted of pre‐activities and post‐activities in relation to a content lecture. A 12‐question survey was administered at the end of the post‐activities for each respective subject in order to investigate students’ perceptions of the ICL classes. Follow‐up email interviews were conducted with students, professors, and teaching assistants. What the researchers found The pre‐activities involved tasks to activate students’ prior knowledge on the respective content lecture subjects, vocabulary previews, and the teaching of note‐taking strategies. The purpose of the post‐activities was to reinforce students’ learning and understanding of the knowledge they acquired from the pre‐activities and the content lectures. Students found vocabulary the most difficult part in understanding English lectures, although they were aware of the importance of vocabulary to their studies. Most students preferred the more integrated aspect of ICL classes than they did language‐focused classes. Mostly easier content materials should be dealt with in class with some advanced materials mixed in to boost students’ participation. Providing a scaffolded language environment during ICL pre‐activities has the potential to elevate students’ content knowledge and encourage them to improve language ability. Things to consider There is a need for continued research and development of effective ICL methods for science and engineering students and particularly for those entering EMI‐implementing tertiary schools. This study investigated the case of a Korean science and engineering university; thus, its implications may be limited to other similar settings. In their first year, L2 students need most help in adjusting to college life set in an EMI environment. It is our hope that this study will stimulate interest in many language educators and serve as a start for further research and development of similar programs in the future.

System-level EMC assessment for military vehicular communication systems based on a modified four-level assessment model

With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficiency and accuracy for the specific case of military vehicular communication systems. Face to this situation, a modified four-level assessment model is proposed in the paper. First, the development of EMC assessment technology is briefly reviewed, and the theoretical mechanism of EMI environment is introduced. Then, the architecture of the proposed model is outlined, and the assessment methods are explored. To demonstrate the application of it, an example involving a communication system in a military vehicle is presented. From the physical layer to the signal layer, a hierarchical assessment on the entire system is successfully performed based on the proposed model, and we can make a qualitative EMC assessment on the EMC performance of the system. Based on a comparison with the traditional model, we conclude that the proposed model is more accurate, more efficient and less time-consuming, which is suitable for the EMC assessment on military vehicular communication systems. We hope that the proposed model will serve as a useful reference for system-level EMC assessments for other systems.

Predictive validity of the IELTS in an English as a medium of instruction environment

AbstractAs access to a university education has increased globally, there have also been increases in the number of universities that use English as a medium of instruction (EMI) and in the number of non‐English‐speaking students studying in English‐speaking countries. Correspondingly, the English language proficiency of students studying in EMI environments is becoming increasingly significant. Using a large sample of 953 undergraduate students at an EMI university in the United Arab Emirates (UAE), this paper examines the predictive validity of the International English Language Testing System (IELTS) as it pertains to the academic success of students as determined by grade point average and addresses implications and appropriateness of further language support. Results indicate that IELTS scores are a meaningful predictor of academic success, especially in the EMI environment that exists in the UAE. Lower than the IELTS guidelines, an IELTS 6.0 seems to be a key benchmark that predicts academic success. It may be that this more moderate English proficiency score is a better fit for non‐English‐speaking countries, but that further language support embedded into degree programmes is necessary except at the highest proficiency levels, and that a bilingual option should be considered at the lowest proficiency levels.

Promoting Student Engagement Through Outcomes-based Education in an EAL Environment

Outcomes-based education is an educational theory that has been promoted, and adopted in several education systems around the world since the early 1990s. Many programs have been adapted successfully over time while others have been phased out for various reasons, including interpretations, issues with assessment, increased instructor workload and perhaps more philosophical issues concerning the nature of learning. However, while there may be a case to be made for holistic learning being lost in a rigid, atomistic approach, there is undoubtedly a range of benefits. One of these is that a well-designed outcomes-based program can help facilitate student engagement because of the nature of the activities and tasks required to demonstrate performance. An outcomes-based process is also one of the requirements of most accrediting bodies in order to demonstrate accountability, and for setting clear statements of what students will be able to do after particular phases of learning, by the end of a course or upon graduation.One particular learning outcome of relevance to EMI and CLIL environments is the requirement to demonstrate the ability to communicate effectively. In undergraduate education, the objective of this particular outcome has two main features; one is to facilitate cognitive development through the acquisition, internalization and articulation of knowledge, and the second is to enable graduates to enter the workplace and be accepted as members of the disciplinary discourse community. As such, the responsibility of each program is to ensure that steps are taken to provide every opportunity for this to be achieved and not just through the frontloading of language skills in earlier language courses.This paper outlines an outcomes-based approach applied to an undergraduate Humanities elective course for EAL students at an engineering institute in the Middle East. The aim of the design is to embed a significant language requirement while engaging learners in a range of stimulating, incidental and explicit, multi-modal learning channels.

Analyzing and Mitigating the Near-field Radiations from PCB of GPS-based Vehicle Tracking System

The EMI/electromagnetic compatibility (EMC) analysis is becoming very important in today’s world of dense EMI environment. As we go toward accuracy and stability of any electronic product in dense EMI field, it is necessary to test it at printed circuit board (PCB) level. This paper describes the measurement technique of scanning of PCB using EMC Precision Scan Tool. The result of near-field measurement indicates the intensity of radiation of each component on PCB. This study is proposed to estimate the radiation field at component level. The near-field based techniques have been widely used in EMC studies because of the high accuracy and reliability. With appropriate model extraction and simulation tools, near-field scanning can be used to predict electromagnetic emissions. With proper shielding, the near-field radiations can be reduced. The near-field radiations can be used to predict far-field radiations from the system, before practically testing in EMI/EMC Laboratory or getting installed at end-user applications. Two models for global positioning system (GPS)-based vehicle tracking system used in research work have been proposed in this article. One is GPRS based and the other is SMS based, intended to be used in stringent environment and ground-based army vehicle. The near-field radiations have been taken at PCB level in dB ¼V for a range of 100 kHz-2.5 GHz frequency band. Maximum radiations of around 90–130 dB ¼V were found. The paper proposes Mu-metal and HE-30 shielding materials for mitigating low- and high-frequency radiations. The GPS VTS GPRS based board and GPS VTS SMS Tx board with HE-30 enclosures had been tested in national EMI Test Laboratory, Automotive Research Association of India (ARAI), for the frequency bands 100 KHz-2.5 GHz. The results had been compared with MIL-461E EMI/EMC standard, and had been found to be satisfactory. The low-frequency radiation level was found to be just within the acceptable limits as per the standard.

Analyzing and mitigating the near-field radiations from PCB of GPS-based vehicle tracking system

AbstractThe EMI/electromagnetic compatibility (EMC) analysis is becoming very important in today’s world of dense EMI environment. As we go toward accuracy and stability of any electronic product in dense EMI field, it is necessary to test it at printed circuit board (PCB) level. This paper describes the measurement technique of scanning of PCB using EMC Precision Scan Tool. The result of near-field measurement indicates the intensity of radiation of each component on PCB. This study is proposed to estimate the radiation field at component level. The near-field based techniques have been widely used in EMC studies because of the high accuracy and reliability. With appropriate model extraction and simulation tools, near-field scanning can be used to predict electromagnetic emissions. With proper shielding, the near-field radiations can be reduced. The near-field radiations can be used to predict far-field radiations from the system, before practically testing in EMI/EMC Laboratory or getting installed at e...

A Multichannel EEG Acquisition Scheme Based on Single Ended Amplifiers and Digital DRL

Single ended (SE) amplifiers allow implementing biopotential front-ends with a reduced number of parts, being well suited for preamplified electrodes or compact EEG headboxes. On the other hand, given that each channel has independent gain; mismatching between these gains results in poor common-mode rejection ratios (CMRRs) (about 30 dB considering 1% tolerance components). This work proposes a scheme for multichannel EEG acquisition systems based on SE amplifiers and a novel digital driven right leg (DDRL) circuit, which overcome the poor CMRR of the front-end stage providing a high common mode reduction at power line frequency (up to 80 dB). A functional prototype was built and tested showing the feasibility of the proposed technique. It provided EEG records with negligible power line interference, even in very aggressive EMI environments.

Rail Elevated Bridge Bearing Displacement Monitoring Based on FBG Sensor

In order to know the bridge bearing operation condition, monitoring bearing displacement was an alternative way. Considering the special field environment of rail elevated bridge and some existing problems of EM-based sensors, needle-shape differential FBG displacement sensors were designed which ensured the long-term stability monitoring under EMI environment. Comparing to the wire-shape FBG displacement sensor, the contact measure type through the sensor needle-shape rod in this paper not only simplified the installation process in-situ, but also could reflect the accurate test direction of bridge bearing. The good linear relationship between sensor wavelength and load verified the rationality of designed differential structure. The practicability in actual engineering application of needle-shape FBG sensor was revealed by a certain rail elevated bridge bearing displacement continuous monitoring results.

Distributed High-Precision Field Testing System of Construction Machinery Based on CAN Bus

The main objective of this work is development of a type of status parameter testing system based on CAN bus for construction machinery. Various difficulties due to over-abundant parameters of testing and controlling, many different types of transducer, changes and anomalies in the operation temperature and harsh EMI environment are considered in the accomplishment. The design of intelligent field testing node is demonstrated in detail. The intelligent node consists of embedded microcontroller AT89C52, high-precision signal conditioning circuits, CAN interface module and other peripheral circuits. The intelligent node uses software auto-zero correction and full-scale correction as well as the method of second-degree parabola interpolation to deal with the non-linear characteristic of the measured data. Hence, it implements the high-precision detection and measurement. In addition, the intelligent connects to the host computer via CAN bus to form a distributed high-precision status parameters testing system. The hardware circuit of operation status parameters measurement and communication interface circuit are developed and described, and the software is also accomplished with C language and LabVIEW. The system has the advantages of simple structure, reliable performance, significant capability of real time processing, powerful anti-jamming performance and so forth. Meanwhile, the system has great application prospect.

Application of nonlinear compensation to limit input dynamic range in analog optical fiber links

The dynamic range of a signal at the input of a measurement system during a short circuit test is increased several times by the nominal input voltage. Saturation of the measurement system may occur in a device under failure test. This paper introduces the application of a nonlinear compensation to limit the voltage range at the input of a voltage controlled oscillator which is used to produce the pulsed frequency modulation needed to transmit the analog signals over the optical fiber links. The proposed dynamic range compensation system is based on non-linear circuits to accommodate the input range of the voltage controlled oscillator. This approach increases the transient signal handling capabilities of the measuring system. This work demonstrates that the nonlinear compensated optical fiber approach yields a unique, electrically isolated, lightning-proof analog data transmission system for remote measuring systems in the highly aggressive EMI environment of high-power test laboratories.

Nonlinear compensation to enhance the input dynamic range in analog optical fiber links for the high current short circuit test

Due to their galvanic insulation and EMI immunity properties, optical fiber links have been used in the transmitter–receiver system of an analog voltage measuring system at a high-power mid-voltage testing laboratory with a highly aggressive EMI environment. This paper introduces the application of a nonlinear compensation to limit the voltage range at the input of a voltage-controlled oscillator, which is used to produce the pulsed frequency modulation needed to transmit the analog signals over the optical fiber links. The proposed dynamic range compensation system is based on nonlinear circuits to accommodate the input range of the voltage-controlled oscillator. This approach increases the transient signal handling capabilities of the measuring system. This work demonstrates that the nonlinear compensated optical fiber approach yields a unique, electrically isolated, lightning-proof analog data transmission system, for remote measuring systems in the highly aggressive EMI environment of high-power test laboratories.