On the Security of Millimeter Wave Vehicular Communication Systems using Random Antenna Subsets

Millimeter wave (mmWave) vehicular communica tion systems have the potential to improve traffic efficiency and safety. Lack of secure communication links, however, may lead to a formidable set of abuses and attacks. To secure communication links, a physical layer precoding technique for mmWave vehicular communication systems is proposed in this paper. The proposed technique exploits the large dimensional antenna arrays available at mmWave systems to produce direction dependent transmission. This results in coherent transmission to the legitimate receiver and artificial noise that jams eavesdroppers with sensitive receivers. Theoretical and numerical results demonstrate the validity and effectiveness of the proposed technique and show that the proposed technique provides high secrecy throughput when compared to conventional array and switched array transmission techniques

A Study on the Optimization of High School Buildings for Evacuation Safety: Classroom Layout and Ramps in Korea

This study used the Pathfinder program to evaluate evacuation safety by assuming evacuation training in high school buildings and changing classroom layout. Analysis of the final evacuation requirements for Scenario 2, which currently has a concentration of classrooms on the third floor of the building, showed that Scenario 2 reduced 29.6 seconds to 173.9 seconds compared to Scenario 1's 203.5 seconds. However, the analysis of Scenario 3, in which 10 classrooms and personnel of three grades were placed equally on the left and right sides of the building, showed that the final evacuation requirements were reduced 3.9 seconds to 170.0 seconds compared to Scenario 2, but there was no significant difference. Scenario 3, which has more the efficiency of school year operation by placing classroom layout on the same floor by grade level than Scenario 2, in which more classrooms and students were placed downstairs. In each scenario, an analysis of the final evacuation requirements showed that the evacuation exit T1 on the left side of the building was 28 seconds or more shorter than T3 on the right side of the building. Therefore, it was analyzed that proper classroom layout and ramp facilities in high school buildings ensure evacuation safet

Recent Trends in Measures to Correct Educational Inequalities in OECD Countries: Application of Text Mining Method

The aim of this study is to analyse how OECD countries view educational inequality, and what the important policy issues are in relation to the education inequality that these countries are experiencing. Analysis results were obtained, through the text mining analysis method, for academic papers dealing with educational inequality in OECD countries. As a result of the analysis, various policy issues faced by OECD countries were classified into five categories. These five policy topics can be summarized as: inequality in primary schools; reform of support programmes for university students; measures to recognize the diversity of migrants; legislation regarding educational inequality measures; and promotion of protection for women in the labour market

Molnupiravir and risk of post-acute sequelae of covid-19: Cohort study

OBJECTIVE: To examine whether treatment with the antiviral agent molnupiravir during the first five days of SARS-CoV-2 infection is associated with reduced risk of post-acute adverse health outcomes. DESIGN: Cohort study. SETTING: US Department of Veterans Affairs. PARTICIPANTS: 229 286 participants who tested positive for SARS-CoV-2 between 5 January 2022 and 15 January 2023, had at least one risk factor for progression to severe covid-19, and survived the first 30 days after testing positive were enrolled. 11 472 participants received a prescription for molnupiravir within five days of the positive test result and 217 814 received no covid-19 antiviral or antibody treatment (no treatment group). MAIN OUTCOME MEASURES: Risks of post-acute sequelae of SARS-CoV-2 (PASC, defined based on a prespecified set of 13 post-acute sequelae), post-acute death, post-acute hospital admission, and each individual post-acute sequela between the molnupiravir group and no treatment group were examined after application of inverse probability weighting to balance the treatment and no treatment groups. Post-acute outcomes were ascertained from 30 days after the first SARS-CoV-2 positive test result until end of follow-up. Risks on the relative scale (relative risk or hazard ratio) and absolute scale (absolute risk reduction at 180 days) were estimated. RESULTS: Compared with no treatment, molnupiravir use within five days of a positive SARS-CoV-2 test result was associated with reduced risk of PASC (relative risk 0.86 (95% confidence interval 0.83 to 0.89); absolute risk reduction at 180 days 2.97% (95% confidence interval 2.31% to 3.60%)), post-acute death (hazard ratio 0.62 (0.52 to 0.74); 0.87% (0.62% to 1.13%)), and post-acute hospital admission (0.86 (0.80 to 0.93); 1.32% (0.72% to 1.92%)). Molnupiravir was associated with reduced risk of eight of the 13 post-acute sequelae: dysrhythmia, pulmonary embolism, deep vein thrombosis, fatigue and malaise, liver disease, acute kidney injury, muscle pain, and neurocognitive impairment. Molnupiravir was also associated with reduced risk of PASC in people who had not received a covid-19 vaccine, had received at one or two vaccine doses, and had received a booster dose, and in people with primary SARS-CoV-2 infection and reinfection. CONCLUSIONS: In people with SARS-CoV-2 infection and at least one risk factor for progression to severe covid-19, compared with no treatment, molnupiravir use within five days of infection was associated with reduced risk of PASC in people who had not received a covid-19 vaccine, had received one or two vaccine doses, and had received a booster dose, and in those with primary SARS-CoV-2 infection and reinfection. Among people at high risk of progression to severe covid-19, molnupiravir use within five days of SARS-CoV-2 infection may be a viable approach to reduce the risk of PASC

ALGAE TO BIODIESEL

In the spring of 2010, a CBE 459 design team focused on cultivating algae with the SimgaeTM Algal Biomass Production System, extracting algal lipids using OriginOilTM single-step extraction technology, and converting lipids into green diesel fuel. It was determined that the process was profitable, but required a staggering capital investment of 2.8 billion dollars. In the past year, both public and private institutions have joined the race to produce biofuels from an algal feedstock in an economically responsible manner that is by maintaining profitability while minimizing high capital costs. The intention of this report is to contribute to the global discourse on alternative-fuels and to reevaluate the promise of algae as a renewable resource for alternative fuels in light of the latest research and technological advances. The algae-to-biofuel venture was segmented into three modules: algal cultivation, lipid extraction and lipid processing. Each module was studied thoroughly and several strategies were proposed for the reduction of its associated fixed, capital and variable costs. As contrasted with a previous study, it was concluded that heterotrophic algal cultivation and transesterification lipid- processing technologies would improve the efficiency and reduce the total capital investment. Once each module was designed in detail, the three segments were stitched together to perform an overall economic analysis. Based on the current market price of $3.30 per gallon for pure biodiesel, a project life of 15 years, and a 15$1.3 billion and the Return on Investment (ROI) was determined to be 32%. Although these economic results are promising, they are based on an analysis that necessarily invoked highly uncertain postulates in the dearth of published data. For example, the kinetics used to model the lipid-processing module were based on data collected for palm oil at similar conditions, while the details of lipid-extraction energy usage for a high-density slurry were approximated on the basis of results for low-density slurry. Furthermore, it was concluded that the income from the sale of the algal biomass byproduct of lipid-extraction is a critical factor in the profitability. Based on its protein content, this report considered the use of algal biomass as animal feed and determined its economic worth accordingly. However, to ensure the economic success of biodiesel production, an additional analysis should focus on algal usage of biomass as a feedstock and confirm the safety of its use. Further analyses could examine other potential applications for the byproduct, including opportunities within the pharmaceutical and power generation industries. Overall, in order to convince investors that the attractive economics published in this report may be translated into actual earnings, it is critical to move beyond modeling. Pilot studies must be conducted in order to bolster the proposed algae-to-biodiesel venture with experimental data and identify possible pitfalls

Optimal Container Migration for Mobile Edge Computing: Algorithm, System Design and Implementation

Edge computing is a promising alternative to cloud computing for offloading computationally heavy tasks from resource-constrained mobile user devices. Placed at the edge of the network, edge computing is particularly advantageous to delay-limited applications for having a short distance to end- users. However, when a mobile user moves away from the service coverage of the associated edge server, the advantage gradually vanishes, increasing response time. Although service migration has been studied to address this problem focusing on minimizing the service downtime, both zero-downtime and the amount of traffic generated as a result of migration need further study. In this paper, an optimal live migration for containerized edge computing service is studied. This paper presents three zero-downtime migration techniques based on state duplication and state reproduction techniques, and then, proposes an optimal migration technique selection algorithm that jointly minimizes the response time and network traffic during migration. For validation and performance comparison, the proposed migration techniques are implemented on off-the-shelf hardware with Linux operating system. The evaluation results showed that compared with a naive migration, the optimal approach reduced the response time and network load by at least 74.75% and 94.79%, respectively, under considered scenarios