Robust Power Interface for Smart Grid with Renewable Energy Source-to-Grid Functionality

Many renewable energy companies design wind turbine generators, solar panels, or electrical car batteries with different specifications according to their management philosophy. And typical commercial power converters are not universally designed for all different types of renewable energy systems. Because of this lack of flexibility and interoperability, a universal and scalable smart grid power converter design is desirable. Designing a robust controlled bi-directional power converter is the motivation for this thesis as the first step to develop a more universal converter topology connecting renewable energy sources and the electrical smart-grid of the future. Renewable energy such as wind or solar power are promising alternatives with many advantages to traditional energy sources but they cannot provide a constant power flow due to the inherent variability of weather. For example, wind speed fluctuates depending on its elevation and solar irradiance fluctuates when moving clouds cover the sun. These example scenarios can be considered as uncertainty and one can assume that uncertainty is time varying as well. For these reasons, it is clear that wind turbine generators and solar panels cannot generate constant power levels and it may result in malfunctions in the converter and instability in the grid

Life Alert System for Vulnerable Adults who Live Alone

As medical technology and the standard of living have improved, the number of vulnerable adults who live alone has increased. Asking for help themselves may be impossible if they have a medical or life issue. Some accidents may go unnoticed for individuals living alone. When accidents regarding vulnerable adults occur, it may take days or weeks to become known by family or neighbors. To solve this problem, a life alert system was designed for vulnerable adults in their homes. To demonstrate the system, A fusion of different sensors were set up in a booth to detect the user’s motion over an extended time period. When the system through the sensors considers a possibility that an accident has occurred, a camera turns on and shows the accident scene through a website. An emergency response agency, a social work agency, or family member is alerted to this website when the camera turns on. This allows a prompt reaction to assist the vulnerable adult

Small Signal Model Averaging of Bi-Directional Converter

We consider the problem of modeling a bi-directional AC/DC converter using a small signal approach coupled with cycle averaging to simplify the model for use in digitized control. Small power sources (less than or equal to 1000W) tend to have more abrupt transient power flow due to the associated characteristic low inertia. This is prevalent in small wind turbine systems. In an effort to reduce the complexity of system control under fast power transients, we develop an averaged model which allows for more advanced controller design while keeping computations reasonable low. This effort is intended to complement related work in distributed generation power flow measurement and control suitable for emerging smart-grid and micro-grid systems. We also utilize a more accurate inductor model incorporating resistive effects for the converter power coupling device. Simulation results are provided demonstrating the capability of the model

Toward Quantum Secured Distributed Energy Resources: Adoption of Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD)

Quantum computing is a game-changing technology that affects modern cryptography and security systems including distributed energy resources (DERs) systems. Since the new quantum era is coming soon in 5–10 years, it is crucial to prepare and develop quantum-safe DER systems. This paper provides a comprehensive review of vulnerabilities caused by quantum computing attacks, potential defense strategies, and remaining challenges for DER networks. First, new security vulnerabilities and attack models of the cyber-physical DER systems caused by quantum computing attacks are explored. Moreover, this paper introduces potential quantum attack defense strategies including Quantum Key Distribution (QKD) and Post-Quantum Cryptography (PQC), which can be applied to DER networks and evaluates defense strategies. Finally, remaining research opportunities and challenges for next-generation quantum-safe DER are discussed

The Pyramid of Injury: Estimation of the Scale of Adolescent Injuries According to Severity

Objectives Due to their developmental characteristics, adolescents have a higher probability than other age groups of experiencing injuries caused by accidents, violence, and intentional self-harm. The severity and characteristics of injuries vary by the intentionality and mechanism of injury; therefore, there is a need for a national-level estimate of the scale and the severity of injuries in adolescents that takes these factors into account. Methods By using data from the Emergency Department-based Injury In-depth Surveillance Data, National Emergency Department Information System, the Korean National Hospital Discharge In-depth Injury Survey, and cause of death statistics, we calculated the emergency department (ED) visit rate, hospitalization rate, and death rate of injuries per 100 000 adolescents for each injury mechanism. The calculated rates were used to generate the injury pyramid ratio (ratio of death rate to hospitalization rate to ED visit rate) to visualize the scale and the severity of the injury. Results The mortality rate in adolescents due to injury was 10/100 000; the corresponding rates for hospitalization and ED visits were 1623 and 4923, respectively, resulting in an injury pyramid ratio with the general pyramid form, with a 1:162:492 ratio of deaths to hospitalizations to ED visits. The mortality rate due to suicide/intentional self-harm was 5/100 000, while 35 were hospitalized for this reason and 74 made ED visits. The pyramid ratio of 1:7:15 for intentional self-harm/suicide showed a steep pyramidal form, indicating considerable lethality. The mortality rate due to motor vehicle collisions (MVCs) was 3/100 000; 586 were hospitalized for this reason, while 1023 made ED visits. The pyramid ratio of 1:195:341 for MVCs showed a gradual pyramid form, indicating that the lethality was low and the scale of injury was high. Conclusions The main categories of injuries in adolescents were visualized in pyramid form, contributing to an understanding of the scale of each injury by mechanism in terms of levels of death, hospitalization, and ED visits. These findings will be helpful for understanding how to prioritize injuries in adolescents

sj-docx-1-cat-10.1177_10760296221127276 - Supplemental material for Association of Lupus Anticoagulant status with Disease Course in SARS-CoV-2 (COVID-19) Infection

Supplemental material, sj-docx-1-cat-10.1177_10760296221127276 for Association of Lupus Anticoagulant status with Disease Course in SARS-CoV-2 (COVID-19) Infection by Suhyeon Woo, MD, Bohyun Kim, MD, PhD, Nam Hun Heo, MS, Min-sun Kim, MD, Young Ahn Yoon, MD, and Young-Jin Choi, MD, PhD in Clinical and Applied Thrombosis/Hemostasis</p

Dual-source abdominopelvic computed tomography: Comparison of image quality and radiation dose of 80 kVp and 80/150 kVp with tin filter.

ObjectiveTo compare the radiation dose and the objective and subjective image quality of 80 kVp and 80/150 kVp with tin filter (80/Sn150 kVp) computed tomography (CT) in oncology patients.MethodsOne-hundred-and-forty-five consecutive oncology patients who underwent third-generation dual-source dual-energy CT of the abdomen for evaluation of malignant visceral, peritoneal, extraperitoneal, and bone tumor were retrospectively recruited. Two radiologists independently reviewed each observation in 80 kVp CT and 80/Sn150 kVp CT. Modified line-density profile of the tumor and contrast-to-noise ratio (CNR) were measured. Diagnostic confidence, lesion conspicuity, and subjective image quality were calculated and compared between image sets. The effective dose and size-specific dose estimate (SSDE) were calculated in the image sets.ResultsModified line-density profile analysis revealed higher attenuation differences between the tumor and normal tissue in 80 kVp CT than in 80/Sn150 kVp CT (127 vs. 107, P = 0.05). The 80 kVp CT showed increased CNR in the liver (8.0 vs. 7.6) and the aorta (18.9 vs. 16.3) than the 80/Sn150 kVp CT. The 80 kVp CT yielded higher enhancement of organs (4.9 ± 0.2 vs. 4.7 ± 0.4, PConclusionsThe 80 kVp CT reduced the radiation dose by 45.2% in oncology patients while showing comparable or superior image quality to that of 80/Sn150 kVp CT for abdominal tumor evaluation