The impact of repetitive unclamped inductive switching on the electrical parameters of low-voltage trench power nMOSFETs

The impact of hot-carrier injection (HCI) due to repetitive unclamped inductive switching (UIS) on the electrical performance of low-voltage trench power n-type MOSFETs (nMOSFETs) is assessed. Trench power nMOSFETs with 20- and 30-V breakdown voltage ratings in TO-220 packages have been fabricated and subjected to over 100 million cycles of repetitive UIS with different avalanche currents IAV at a mounting base temperature TMB of 150°C. Impact ionization during avalanche conduction in the channel causes hot-hole injection into the gate dielectric, which results in a reduction of the threshold voltage VGSTX, as the number of avalanche cycles N increases. The experimental data reveal a power-law relationship between the change in the threshold voltage ΔVGSTX and N. The results show that the power-law prefactor is directly proportional to the avalanche current. After 100 million cycles, it was observed in the 20-V rated MOSFETs that the power-law prefactor increased by 30% when IAV was increased from 160 to 225 A, thereby approximating a linear relationship. A stable subthreshold slope with avalanche cycling indicates that interface trap generation may not be an active degradation mechanism. The impact of the cell pitch on avalanche ruggedness is also investigated by testing 2.5- and 4- m cell-pitch 30-V rated MOSFETs. Measurements showed that the power-law prefactor reduced by 40% when the cell pitch was reduced by 37.5%. The improved VGSTX stability with the smaller cell-pitch MOSFETs is attributed to a lower avalanche current per unit cell resulting in less hot-hole injection and, hence, smaller VGSTX shift. The 2.5-m cell-pitch MOSFETs also show 25% improved on -state resistance RDSON, better RDSON stability, and 20% less subthreshold slope compared with the 4-m cell-pitch MOSFETs, although with 100% higher initial IDSS and less IDSS stability with avalanche cycling. These results are important for manufacturers of automotive MOSFETs where multiple avalanche occurrences over the lifetime of the MOSFET are expected

Simultaneous Forward-Backward Prony Estimation

Power system dynamic stability can be evaluated through the analysis of transient oscillations that occur following significant system events. One of the earliest methods for this type of study is Prony analysis, which estimates the system's electromechanical modes. While previous studies have highlighted advantages of performing Prony analysis on data in the forward and backward directions, the proposed method does so simultaneously. As a result, signal poles corresponding to electromechanical modes can be distinguished from spurious poles more reliably. The method also produces a single mode estimate, where independent application in the forward and backward directions would produce two estimates for each mode. The method is validated using simulated and measured power system data

Evaluation of the International Development Research Centre's experience with the devolution of international Secretariats

The evaluation develops guiding principles to inform future devolution practices: 1) Plan Early 2) Build Capacity 3) Collaborate and Partner 4) Develop a Transition Strategy 5) Assure Continuity 6) Build Good Governance and Management Frameworks, and 7) Demonstrate Return on Investment and Secure Funding. Beginning in 1992, international secretariats were created by IDRC as a modality for incubating innovative research ideas funded by multiple donors. Although “housed” in IDRC, they were expected to operate semi-autonomously. Based on the rationale for devolution, geographical location, perceived degree of success, donor makeup, and post devolution longevity, a sample of seven secretariats was selected for study

Inferring Previously Uninstalled Applications from Residual Partial Artifacts

In this paper, we present an approach and experimental results to suggest the past presence of an application after the application has been uninstalled and the system has remained in use. Current techniques rely on the recovery of intact artifacts and traces, e.g., whole files, Windows Registry entries, or log file entries, while our approach requires no intact artifact recovery and leverages trace evidence in the form of residual partial files. In the case of recently uninstalled applications or an instrumented infrastructure, artifacts and traces may be intact and complete. In most cases, however, digital artifacts and traces are al- tered, destroyed, and disassociated over time due to normal system operation and deliberate obfuscation activity. As a result, analysts are often presented with partial and incomplete artifacts and traces from which defensible conclusions must be drawn. In this work, we match the sectors from a hard disk of interest to a previously constructed catalog of full files captured while various applications were installed, used, and uninstalled. The sectors composing the files in the catalog are not necessarily unique to each file or application, so we use an inverse frequency-weighting scheme to compute the inferential value of matched sectors. Similarly, we compute the fraction of full files associated with each application that is matched, where each file with a sector match is weighted by the fraction of total catalog sectors matched for that file. We compared results using both the sector-weighted and file- weighted values for known ground truth test images and final snapshot images from the M57 Patents Scenario data set. The file-weighted measure was slightly more accurate than the sector-weighted measure, although both identified all of the uninstalled applications in the test images and a high percentage of installed and uninstalled applications in the M57 data set, with minimal false positives for both sets. The key contribution of our work is the sug- gestion of uninstalled applications through weighted measurement of residual file fragments. Our experimental results indicate that past application activity can be reliably indicated even after an application has been uninstalled and the host system has been rebooted and used. The rapid and reliable indication of previously uninstalled applications is useful for cyber defense, law enforcement, and intelligence operations. Keywords: digital forensics; digital artifact; digital trace; partial artifact; residual artifact; uninstalled applicatio

Diversity bias in colorectal surgery: a global perspective

Colorectal surgery; Diversity; RaceCirugía de colon y recto; Diversidad; RazaCirurgia de còlon i recte; Diversitat; RaçaThere is a specific lack of data on equity and injustices among colorectal surgeons regarding diversity. This study aimed to explore colorectal surgeon’s lived experience of diversity bias with a specific focus on gender, sexual orientation or gender identity and race or religion. A bespoke questionnaire was designed and disseminated to colorectal surgeons and trainees through specialty association mailing lists and social media channels. Quantitative and qualitative data points were analysed. 306 colorectal surgeons responded globally. 58.8% (n = 180) identified as male and 40.5% (n = 124) as female. 19% were residents/registrars. 39.2% stated that they had personally experienced or witnessed gender inequality in their current workplace, 4.9% because of sexual orientation, and 7.5% due to their race or religion. Sexist jokes, pregnancy-related comments, homophobic comments, liberal use of offensive terms and disparaging comments and stereotypical jokes were commonly experienced. 44.4% (n = 135) did not believe their institution of employer guaranteed an environment of respect for diversity and only 20% were aware of society guidelines on equality and diversity. Diversity bias is prevalent in colorectal surgery. It is necessary to work towards real equality and inclusivity and embrace diversity, both to promote equity among colleagues and provide better surgical care to patients.Open access funding provided by Università degli Studi della Campania Luigi Vanvitelli within the CRUI-CARE Agreement. All authors have no source of funding