EMC
Electromagnetic compatibility (EMC) is the capacity of electrical and electronic systems to function without unacceptable degradation in their intended electromagnetic environment, while limiting the electromagnetic disturbances they generate that could impair other systems.[1][2] This discipline addresses both the emission of unintended electromagnetic energy from devices—such as radiated or conducted interference—and their immunity to external electromagnetic phenomena, ensuring coexistence in increasingly dense electronic ecosystems without reliance on unverified regulatory narratives.[3][4] Central to EMC are empirical measurements of electromagnetic fields, currents, and voltages, derived from fundamental physical laws governing wave propagation and circuit behavior, which dictate that all high-frequency signals manifest as electromagnetic waves traveling along defined paths.[5] Compliance involves rigorous testing protocols to quantify emissions against predefined limits and verify susceptibility thresholds, preventing issues like signal distortion or equipment malfunction in shared spectra.[6] International standards, including those from the IEC and ETSI, establish these limits based on reproducible laboratory data, mandating certification for market access in regions enforcing directives like the EU's EMC framework.[7][8] Defining characteristics include loop current analysis for interference sources and shielding efficacy evaluations, which have proven critical in sectors from telecommunications to aerospace, where non-compliance can cascade into systemic failures empirically observed in uncontrolled environments.[9][10]Technology and engineering
Electromagnetic compatibility
Electromagnetic compatibility (EMC) refers to the ability of electronic and electrical devices to operate as intended within their electromagnetic environment without causing or suffering unacceptable electromagnetic interference (EMI).[11] This discipline encompasses the design, analysis, and verification processes that ensure equipment emissions do not exceed specified limits and that devices maintain functionality despite external disturbances.[12] EMC is essential in engineering because unintended EMI can degrade performance, compromise safety, or lead to system failures, particularly in environments with multiple radiating sources such as industrial facilities, vehicles, and telecommunications networks.[13] The foundational principles of EMC revolve around two primary aspects: electromagnetic emissions and susceptibility. Emissions involve controlling both radiated fields—propagated through space from antennas or unintentional radiators—and conducted emissions, which propagate via power lines or interconnects. Susceptibility, conversely, addresses a device's immunity to external fields, ensuring it rejects noise through measures like shielding, filtering, and proper grounding. These principles derive from Maxwell's equations, which govern electromagnetic wave propagation, and are applied via first-principles modeling of coupling mechanisms such as capacitive, inductive, or radiative paths between sources and victims.[14] Effective EMC engineering minimizes near-field coupling in circuits and far-field propagation in systems, often quantified using metrics like electric field strength in volts per meter or conducted noise in decibels above one microvolt.[15] In practice, EMC challenges arise from the increasing operating frequencies and miniaturization in modern electronics, which amplify unintended radiation; for instance, digital clock edges above 100 MHz can generate broadband emissions mimicking intentional transmitters. Historical developments trace to post-World War II military applications, where radar and communication systems necessitated interference mitigation, evolving into civilian standards by the 1970s amid growing consumer electronics density. Compliance with EMC principles enhances reliability, as evidenced by reduced failure rates in automotive electronics adhering to these guidelines, where EMI has been linked to up to 10% of electronic faults in vehicles.[16] Engineers achieve this through iterative techniques, including component selection for low-noise characteristics and layout optimization to suppress resonances, validated via simulation tools modeling field interactions.[1]EMC testing and standards
Electromagnetic compatibility (EMC) testing evaluates whether electronic devices generate acceptable levels of electromagnetic interference (EMI) and possess sufficient immunity to external disturbances, ensuring reliable operation in shared electromagnetic environments. Emissions testing measures radiated and conducted emissions from the device, while immunity testing assesses resilience to phenomena such as electrostatic discharge (ESD), electrical fast transients (EFT), surges, and radiofrequency fields. These tests are typically performed in controlled environments like semi-anechoic chambers for radiated measurements or open-area test sites, following standardized procedures to quantify field strengths in decibels relative to microvolts per meter (dBμV/m) or current levels.[17] The International Electrotechnical Commission (IEC) 61000 series provides foundational standards for EMC testing methods and limits. IEC 61000-4 specifies immunity test techniques, including Part 4-2 for ESD (up to 8 kV contact discharge), Part 4-3 for radiated RF immunity (1 V/m to 10 V/m across 80 MHz to 6 GHz), and Part 4-6 for conducted RF disturbances (3 V RMS). Emission limits are addressed in related CISPR standards, such as CISPR 11 for industrial equipment and CISPR 32 for multimedia devices, harmonized under IEC frameworks. Generic standards like IEC 61000-6-1 and 61000-6-3 apply to residential, commercial, and light-industrial settings, defining immunity and emission requirements where product-specific standards are absent.[18][15] In the European Union, the EMC Directive 2014/30/EU mandates that apparatus must not generate excessive electromagnetic disturbances or suffer performance degradation from them, requiring conformity assessment via harmonized standards such as EN 61000 series equivalents. Compliance often involves self-certification for most products, with technical documentation including risk assessments and test reports, though Notified Body involvement applies to certain high-risk categories. The directive, effective since April 20, 2016, replaced the 2004/108/EC version to align with New Legislative Framework principles, emphasizing essential requirements over prescriptive testing.[8] In the United States, the Federal Communications Commission (FCC) regulates unintentional radiators under 47 CFR Part 15, Subpart B, which sets emission limits for devices operating above 9 kHz, classifying them as Class A (industrial) or Class B (residential) based on stricter residential thresholds (e.g., 40 dBμV/m at 3 meters for 30-88 MHz). Certification via Supplier's Declaration of Conformity (SDoC) or FCC Equipment Authorization is required, with testing accredited to ANSI C63 series methods. Part 15 focuses on preventing harmful interference without mandating immunity, though voluntary standards like those from SAE may apply in automotive contexts.[19][20] Other regional and sector-specific standards include ISO 7637 for automotive transient immunity and ETSI EN 301 489 for radio equipment, often building on IEC bases. Accreditation bodies like A2LA or ILAC ensure test lab competence, with pre-compliance testing recommended to mitigate redesign costs, as full compliance failures can exceed 10-20% of product development budgets in complex systems.[21]Computing and data storage
EMC Corporation
EMC Corporation was founded in 1979 by Richard Egan and Roger Marino in Hopkinton, Massachusetts, initially focusing on manufacturing and selling memory boards and data storage peripherals compatible with mainframe computers such as those from Prime Computer.[22] The company, whose name derives from the initials of its cofounders, began as a provider of aftermarket upgrades for computer memory and storage, capitalizing on the growing demand for affordable enhancements to expensive proprietary systems in the late 1970s and early 1980s.[23] By the mid-1980s, EMC shifted toward developing its own networked storage platforms, moving beyond simple memory add-ons to integrated data storage solutions.[24] In the 1990s, EMC achieved significant market dominance in enterprise data storage through innovations like the Symmetrix line of high-end disk arrays, first shipped in 1990, which supported symmetric multiprocessing and became a standard for storage area networks (SANs).[24] The company expanded via strategic acquisitions, such as Magna Computer in 1993 for tape storage technology and Epoch Systems for storage management software, enabling it to capture substantial shares of the storage systems market—reaching 34.6% by 2000 with revenues exceeding $8.8 billion that year.[24][23] EMC's portfolio evolved to include software for virtualization, data protection, and analytics, positioning it as a leader in managing the exponential growth of enterprise data volumes during the internet era, with annual revenues climbing to $24.7 billion by 2015.[25] EMC's growth trajectory culminated in its acquisition by Dell Inc., announced on October 12, 2015, in a $67 billion deal that combined Dell's server and PC expertise with EMC's storage dominance to form Dell EMC, enhancing capabilities in hybrid cloud and converged infrastructure.[26] The transaction closed on September 7, 2016, after regulatory approvals, marking one of the largest tech mergers and integrating EMC's approximately 70,000 employees into Dell Technologies.[22] Post-acquisition, EMC's technologies continued to underpin Dell's enterprise storage offerings, including advancements in flash-based and software-defined storage acquired through entities like DSSD in 2014.[24]Scientific conferences and research
Electronic Materials Conference
The Electronic Materials Conference (EMC) is an annual gathering of researchers dedicated to advancing the science and technology of electronic materials, emphasizing their preparation, characterization, and practical applications in devices and systems. Sponsored by the Electronic Materials Committee of The Minerals, Metals & Materials Society (TMS), the event features oral presentations, poster sessions, and invited talks covering topics such as compound semiconductors, silicon and germanium-based materials, wide- and ultra-wide-bandgap semiconductors, nanomaterials, organic and hybrid materials, and novel characterization techniques.[27][28] Established as a key venue for disseminating cutting-edge research, the EMC originated in the late 1950s, with the 42nd conference held in 2000 and the 67th scheduled for June 25–27, 2025, at Duke University in Durham, North Carolina. It frequently coordinates with the Device Research Conference (DRC) to integrate materials innovation with device engineering, enhancing cross-disciplinary insights into fields like optoelectronics, power electronics, and quantum technologies. Attendance typically draws 400–600 participants, including academics, industry professionals, and students, with dedicated awards for outstanding student contributions.[27][29][30] Proceedings from the conference often contribute to special issues in peer-reviewed journals, such as the Journal of Electronic Materials, underscoring its role in peer validation and archival of empirical findings on material properties, growth methods (e.g., molecular beam epitaxy, chemical vapor deposition), and performance metrics like carrier mobility and defect densities. The event's emphasis on verifiable experimental data and reproducible techniques aligns with rigorous standards in materials science, avoiding unsubstantiated theoretical extrapolations. Venues rotate across U.S. universities to leverage local expertise, as seen in the 2024 hosting at the University of Colorado Boulder and the planned 2026 edition at the University of Michigan in Ann Arbor.[31][32]IEEE EMC Symposium
The IEEE International Symposium on Electromagnetic Compatibility (EMC), now commonly referred to as the EMC+SIPI Symposium to incorporate signal and power integrity topics, is the premier annual conference organized by the IEEE Electromagnetic Compatibility Society. It serves as a global forum for engineers, researchers, and academics to present advancements in electromagnetic interference mitigation, compatibility standards, measurement techniques, and related fields such as high-speed digital design and power electronics. The event emphasizes practical solutions to real-world EMC challenges in industries including telecommunications, automotive, aerospace, and consumer electronics.[33][34] The symposium traces its origins to early professional gatherings in the late 1950s, with the first notable event held in New York in 1959, drawing approximately 200 attendees focused on emerging EMC issues in military and commercial systems. A subsequent symposium in Washington, D.C., in June 1960 attracted over 400 participants, reflecting growing interest amid Cold War-era concerns over radio frequency interference in radar and communication equipment. The series formalized as the IEEE International Symposium on EMC, expanding internationally with the first non-U.S. hosting in Tokyo, Japan, in 1984. By the 2020s, it has evolved to include SIPI components, with proceedings archived in IEEE Xplore since the 1970s, encompassing thousands of peer-reviewed papers.[35][36][37] Typically spanning five days, the symposium features technical paper sessions, workshops, tutorials, poster presentations, and an industry exhibition with around 100 vendors showcasing EMC testing equipment, shielding materials, and simulation software. Attendance ranges from 1,500 to 2,000 professionals annually, fostering networking and hands-on demonstrations of compliance methodologies aligned with standards like CISPR and FCC regulations. Recent iterations, such as the 2024 event in Phoenix, Arizona (August 5–9), and the upcoming 2025 symposium in Raleigh, North Carolina (August 18–22), highlight emerging topics including electromagnetic effects of 5G/6G networks, electric vehicle powertrains, and AI-driven interference prediction.[34][38][39] This symposium plays a critical role in advancing EMC as a discipline by disseminating empirical data from computational modeling, laboratory validations, and field measurements, often prioritizing causal mechanisms of interference over regulatory compliance alone. It influences industry practices through contributed standards development sessions and has contributed to the society's broader mission of reducing unintended electromagnetic effects since its formal establishment in the 1960s. Proceedings provide verifiable benchmarks for reproducibility, with historical data showing progressive improvements in measurement precision, such as from early spectrum analyzer techniques to modern vector network analysis.[40][41]Business and insurance
EMC Insurance Companies
EMC Insurance Companies is the trade name of Employers Mutual Casualty Company (EMCC), a mutual insurance company specializing in property and casualty coverage, primarily for businesses.[42] Founded on November 22, 1911, in Des Moines, Iowa, EMCC was established as an assessment association by Iowa manufacturers to provide workers' compensation insurance amid rising industrial accident rates following Iowa's adoption of compulsory workers' compensation laws.[43] By 2019, prior to its full privatization, EMC ranked among the top 60 U.S. property/casualty insurers by net written premiums, with operations focused on commercial lines including general liability, commercial multi-peril, workers' compensation, and auto coverage across multiple states.[44] The company expanded from its initial workers' compensation focus into broader commercial insurance in the mid-20th century, incorporating EMC Insurance Group Inc. as an Iowa-based holding company in 1974 to oversee subsidiaries and facilitate growth.[45] EMCC maintained majority ownership of the group, holding approximately 54% of shares by 2019.[46] On May 9, 2019, EMCC announced a merger agreement to acquire all remaining publicly traded shares of EMC Insurance Group Inc. for $36 per share in cash, valuing the transaction at about $356 million and representing a 50% premium over the prior closing price.[47] [48] Shareholders approved the deal overwhelmingly, and EMCC completed the acquisition on September 19, 2019, delisting the stock from NASDAQ and integrating operations fully under private mutual ownership.[49] [50] Headquartered at 717 Mulberry Street in Des Moines, Iowa, EMC employs over 2,200 people and distributes products through independent agents, emphasizing risk management and loss control services alongside core insurance lines.[51] [52] As of 2025, it continues as a financially stable mutual entity, with subsidiaries like EMCASCO Insurance Company handling specific lines, and maintains an A (Excellent) rating from A.M. Best for its balance sheet strength and operating performance.[42] The company's model prioritizes policyholder mutual interests over shareholder returns, aligning with its origins in serving employer needs without external investor pressures post-privatization.[53]Other uses
Event Mean Concentration
Event Mean Concentration (EMC) is a flow-weighted average pollutant concentration in stormwater runoff for a discrete storm event, defined as the total pollutant mass exported divided by the total runoff volume.[54] This metric captures temporal variations in concentration and discharge rates during rainfall, offering a standardized measure for comparing stormwater quality across events or sites, unlike unweighted averages that ignore flow proportionality.[55] EMCs are central to nonpoint source pollution assessments, particularly in urban watersheds where impervious surfaces amplify pollutant mobilization from accumulated dry-weather deposits.[56] Calculation of EMC typically involves flow-proportional composite sampling, where aliquots are collected based on runoff volume or depth, then analyzed for pollutant levels and aggregated as EMC = (sum of mass emissions) / (total event volume).[57] For monitored events, this equates to integrating instantaneous concentration C(t) and flow Q(t) over the event duration: EMC = [∫ C(t) Q(t) dt] / [∫ Q(t) dt].[54] Discrete grab samples can approximate EMC via volume-weighting, though errors arise if sampling misses peak flows or first-flush effects; detection limits below method quantitation require substitution (e.g., half the limit) for low-concentration events.[56] In applications, EMCs estimate event pollutant loads by multiplying by runoff volume, informing BMP design and regulatory compliance under frameworks like U.S. NPDES permits.[58] Treatment performance is evaluated via influent-effluent EMC ratios, revealing average concentration reductions; for example, urban stormwater EMCs for suspended solids range 22–138 mg/L, total nitrogen 1.4–18.5 mg/L, and total phosphorus 0.17–2.02 mg/L, varying with land use and antecedent dry periods that enhance surface pollutant accumulation.[54][59] Higher EMCs in urban versus rural settings reflect anthropogenic inputs, underscoring land-use-specific databases for load modeling.[56]European Motorcycling Championship
The European Motorcycling Championships refer to a collection of circuit racing series sanctioned by FIM Europe, the continental governing body for motorcycling in Europe under the Fédération Internationale de Motocyclisme (FIM). These championships focus on developing emerging talent through competitive formats using standardized or production-derived motorcycles, typically held as support events to higher-profile series like the FIM JuniorGP World Championship. They emphasize rider skill over extensive modifications, with eligibility often restricted to younger competitors or those without prior world championship experience, spanning classes from small-displacement production bikes to prototype intermediates. Races occur at established European circuits, with seasons comprising 7 to 12 rounds annually, promoting safety standards aligned with FIM regulations.[60] Key series include the FIM Moto2 European Championship, introduced to bridge national and world-level racing, featuring 765cc prototype engines in a single-make format derived from grand prix specifications. The 2025 season schedule includes 11 races across 7 events, commencing May 4 at Circuito do Estoril, Portugal, and concluding November 23 at Circuit Ricardo Tormo, Valencia, Spain, with additional rounds at venues like MotorLand Aragón and Circuit de Barcelona-Catalunya. Riders must meet age criteria (typically under 28) and points limits from prior series to participate, fostering progression to Moto2 World Championship.[61] The Stock European Championship utilizes minimally modified production motorcycles, primarily in 600cc classes, to emphasize stock performance and cost control, running parallel to the Moto2 EC and European Talent Cup. Regulations for 2025 specify technical specs for chassis, engines, and electronics to ensure parity, with events integrated into multi-class weekends for shared logistics and spectator appeal. This series has served as a talent pipeline, with past participants advancing to world superbike or supersport levels.[62] Additional cups like the Supersport 300 European Cup and Superstock 1000 European Cup target entry-level and mid-capacity racing, respectively. The Supersport 300 Cup, for 300-400cc supersport bikes, featured its 2025 opener at Automotodrom Grobnik, Croatia, on May 19, accommodating riders as young as 16 and emphasizing close racing grids. Superstock 1000, using near-stock 1000cc machines, aligns with WorldSBK support races since its reorientation in 2016 from the former European Superbike Championship, prioritizing reliability and rider development over tuning. These formats collectively host 10-15 races per season, with championships decided by cumulative points from sprint-length events.[63]| Championship | Displacement/Class | Typical Rounds (2025) | Eligibility Focus |
|---|---|---|---|
| Moto2 EC | 765cc prototype | 11 races / 7 events | Under 28, limited prior GP points |
| Stock EC | 600cc stock | Integrated with JuniorGP | Emerging national-level riders |
| Supersport 300 Cup | 300-400cc supersport | 8-10 events | Ages 16+, production-based |
| Superstock 1000 Cup | 1000cc stock | Support to WorldSBK/European | Production derivatives, development |