Spatial patterns of record-setting temperatures

We employ record-breaking statistics to study spatial correlations of record-setting terrestrial surface temperatures. To that end, a simple diagnostic tool is devised, reminiscent of a pair-correlation function. Data analysis reveals that while during the hottest years, record-breaking temperatures arrive in “heat waves”, extending throughout almost the entire continental United States, this is not so for all years, not even recently. Record-breaking temperatures generally exhibit spatial patterns and variability quite different from those of the mean temperatures

Cybersecurity and medical devices: Are the ISO/IEC 80001-2-2 technical controls up to the challenge?

This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 24 month embargo from date of publication (Oct 2017) in accordance with the publisher’s archiving policyMedical devices, in the case of malfunction, can have tangible impact on patient safety. Their security, in a world where the Internet of Things has become a reality, is paramount to the continued safety of patients that are dependent upon these devices. The international standard ISO/IEC 80001 – Application of risk management for IT-networks incorporating medical devices presents a unified and amalgamated approach to the safety of medical devices connected to IT networks. Whilst this standard presents a guide for security and risk management in health delivery organisations, its effectiveness with regard to contemporary cybersecurity is unknown. This research employed a structured review process to compare and analyse the ISO/IEC 80001 technical controls standards (ISO/IEC 80001-2-2 and ISO/IEC 80001-2-8), with contemporary cybersecurity best practice, guidelines and standards. The research deconstructed the technical controls and drew links between these standards and cybersecurity best practice to assess the level of harmonisation. Subsequently, a deeper analysis identified the areas of omission, coverage, addition or improvement that may impact the effectiveness of ISO/IEC 80001 to provide effective cybersecurity protection. ISO/IEC 80001 aims to provide a minimal level of cybersecurity however this research demonstrates that there are deficiencies in the standard and identifies the important aspects of cybersecurity that could be improved. This situation has arisen due to the rapidly evolving nature of the cybersecurity environment and the protracted time to revise and republish international standards. This research identified several areas that require urgent consideration, including Emergency Access, Health Data De-Identification, Physical Locks on Devices, Data Backup, Disaster Recovery, Third-Party Components in Product Lifecycle Roadmap, Transmission Confidentiality, and Transmission Integrity. The research will provide health delivery organisations implementing ISO/IEC 80001, assurance as to the level of protection supplied by the ISO/IEC 80001 standard, and the areas that may need enhancement to increase cybersecurity protection and consequently increase in patient safety. Further, the outcomes are expected to influence development of the related international standard, as the findings from this research are being provided to the International Organisations for Standardisation, TC215 Health Informatics, Joint Working Group 7, to inform the review of ISO/IEC 80001 currently in progress

Surface and Buffer Trap Signatures in Fe-doped AlGaN/GaN HEMT Identified by LF S-parameter TCAD Simulations

International audienceIn this paper, the trap signatures located at the GaN cap/SiN interface and in the GaN buffer are clearly identified in the Fe-doped AlGaN/GaN HEMT device by means of low frequency (LF) S-parameter characteristics. For that, LF Sparameter TCAD Sentaurus physics-based 2D simulations are performed for different temperatures ranging from 25°C to 75°C. In fact, the imaginary part of Y22 allows to extract the buffer trap parameters, while the imaginary part of Y21 provides a quantitative information of the traps located at both surface and buffer regions. An excellent agreement between measurement and simulation of Y21 parameter is obtained in this work. An activation energy of Ea= 0.45 eV and a cross section around σn=3×10-16 cm 2 are identified for buffer traps. The computed parameters for the surface traps are ED = ~0.3 eV and σD = ~5×10-18 cm 2

Effets du dopage fer et carbone dans la zone tampon GaN sur les constantes de temps de pièges dans les HEMT

International audienceCe travail étudie expérimentalement par l'analyse des transitoires de courant de drain (DCT) les pièges électriquement actifs dans les transistors à haute mobilité électronique (HEMT) à base d'InAlN/GaN et d'AlN/GaN. L'impact du dopage fer ou carbone dans la couche tampon de GaN est notamment examiné. Un piège de niveau profond positionné à EC-0,63 eV avec une section de capture de σ = ~6×10-15 cm² est identifié pour le transistor InAlN/GaN à dopage Fe. Les mesures DCT montrent par contre que le transistor AlN/GaN HEMT (dopé C) possède quant à lui un piège à électrons positionné à EC-0,33 eV avec une section de capture de 2x10-20 cm². Contrairement au dopage Fe, ces analyses montrent que le buffer à dopage carbone dispose de constantes de temps d'émission de pièges très lentes. Ces caractérisations permettent de définir une méthodologie de tri des composants très utile pour leur fabricant