Realizing Stabilized Landing for Computation-Limited Reusable Rockets: A Quantum Reinforcement Learning Approach

The advent of reusable rockets has heralded a new era in space exploration, reducing the costs of launching satellites by a significant factor. Traditional rockets were disposable, but the design of reusable rockets for repeated use has revolutionized the financial dynamics of space missions. The most critical phase of reusable rockets is the landing stage, which involves managing the tremendous speed and attitude for safe recovery. The complexity of this task presents new challenges for control systems, specifically in terms of precision and adaptability. Classical control systems like the proportional-integral-derivative (PID) controller lack the flexibility to adapt to dynamic system changes, making them costly and time-consuming to redesign of controller. This paper explores the integration of quantum reinforcement learning into the control systems of reusable rockets as a promising alternative. Unlike classical reinforcement learning, quantum reinforcement learning uses quantum bits that can exist in superposition, allowing for more efficient information encoding and reducing the number of parameters required. This leads to increased computational efficiency, reduced memory requirements, and more stable and predictable performance. Due to the nature of reusable rockets, which must be light, heavy computers cannot fit into them. In the reusable rocket scenario, quantum reinforcement learning, which has reduced memory requirements due to fewer parameters, is a good solution.Comment: 5 pages, 5 figure

Thiol-linked peroxidase activity of human ceruloplasmin

AbstractHuman ceruloplasmin exhibited different antioxidant effects according to the electron donors in a metal-catalyzed oxidation system. Purified ceruloplasmin did not play a significant role in the protection of DNA strand breaks in the ascorbate/Fe3+/O2 system. However, when ascorbates were replaced with a thiol-reducing equivalent such as dithiothreitol, DNA strand breaks were significantly prevented by the same amount of ceruloplasmin. Ceruloplasmin did not catalyze the decomposition of H2O2 in the absence of reduced glutathione. On the contrary, ceruloplasmin showed a potent peroxidase ability to destroy H2O2 in the presence of reduced glutathione. In conclusion, the removal of H2O2 by human ceruloplasmin is not simply stoichiometric but thiol-dependent

Multi-Agent Deep Reinforcement Learning for Efficient Passenger Delivery in Urban Air Mobility

It has been considered that urban air mobility (UAM), also known as drone-taxi or electrical vertical takeoff and landing (eVTOL), will play a key role in future transportation. By putting UAM into practical future transportation, several benefits can be realized, i.e., (i) the total travel time of passengers can be reduced compared to traditional transportation and (ii) there is no environmental pollution and no special labor costs to operate the system because electric batteries will be used in UAM system. However, there are various dynamic and uncertain factors in the flight environment, i.e., passenger sudden service requests, battery discharge, and collision among UAMs. Therefore, this paper proposes a novel cooperative MADRL algorithm based on centralized training and distributed execution (CTDE) concepts for reliable and efficient passenger delivery in UAM networks. According to the performance evaluation results, we confirm that the proposed algorithm outperforms other existing algorithms in terms of the number of serviced passengers increase (30%) and the waiting time per serviced passenger decrease (26%).Comment: 6 pages, 5 figure

Pharmacological effects of active saponins from Panax ginseng Meyer

Purpose: To investigate the pharmacological effects of the active saponins isolated from Panax ginseng Meyer (P. ginseng) via extraction, heat treatment, and enzyme conversion. Methods: The effects of active saponins on rat blood were determined using a multichannel analyzer. The population doubling time (PDT) of mesenchymal stem cells (MSCs) and human-derived leukocyte cancer cells (A549) was determined by cell counting. b-galactosidase was measured in human toothderived stem cells (HTS) using a β-galactosidase ELISA kit. Results: Intraperitoneal administration of active saponins resulted in 30.09 % increase in red blood cell count and 55.55 % decrease in blood triglyceride concentrations. The stimulatory effect of active saponins (10 ng/mL) on cellular differentiation was determined based on PDT of MSCs, which decreased by 33.82 % compared to control. A 22.29 % increase in PDT of A549 cells demonstrated the suppressive effects of active saponins on cancer cell growth. Active saponins (10 ng/mL) also decreased intracellular β-galactosidase concentration by 20.42 % in HTS cells. Conclusion: Administration of active saponins to rats extends the lifespan, promotes differentiation in MSCs, suppresses A549 cell differentiation, and reduces TG and b-galactosidase associated with aging in HTS. Thus, active saponins have potentially beneficial effects in humans

Characteristics and Trends of Strawberry Cultivars throughout the Cultivation Season in a Greenhouse

Each strawberry (Fragaria × ananassa) cultivar has its own growth and yield characteristics. However, the characteristics of many cultivars have not been determined at a consistent time and place, making direct comparative analysis difficult. The objective of this study was to identify characteristics and trends of five Korean strawberry cultivars in the same environment during an entire season. Therefore, environmental factors such as daily average air temperature, daily average relative humidity, daily average solar radiation, daily soil temperature, daily soil water content, daily soil electrical conductivity (EC), plant growth characteristics such as the number of leaves, plant height, leaf length, leaf width, and crown diameter, and productivity characteristics such as flowering and fruiting were measured to investigate the possible correlations of the data over one season. The vegetative growth of “Seolhyang” and “Keumsil” was greater than that of “Jukhyang” and “Maehyang”. The yield of “Arihyang” was greater than that of all other cultivars. “Arihyang” also presented the greatest weight per number of fruits. Among environmental factors, higher variability in air temperature and soil water content was correlated to lower total fresh weight in the following week at different degrees for each cultivar. Among the cultivars, the time to the first flowering was delayed by about seven days when the number of leaves increased by one and was reduced by one day per 1 cm increase in plant height. The total fresh weight was enhanced up to 271 g per experimental unit, while the average number of leaves increased by one. The results indicate that the data can be used by those who need information regarding the characteristics of the strawberry cultivars through direct comparative analysis

The Effect of Obstructive Sleep Apnea on DNA Damage and Oxidative Stress

ObjectivesObstructive sleep apnea syndrome (OSAS) is associated with repeated hypoxia and re-oxygenation. This characteristic of OSAS may cause oxidative stress and DNA damage. However, the link of OSAS with oxidative stress and DNA damage is still controversial. In the current study, we investigated whether OSAS causes DNA damage using alkaline single-cell gel electrophoresis (comet assay) and measuring oxidative stress by monitoring serum malondialdehyde (MDA) levels.MethodsFrom March 2009 to August 2010, 51 patients who underwent polysomnography (PSG) during the night were enrolled in this study. We obtained serum from the patients at 6 AM. DNA damage and oxidative stress were evaluated using a comet assay and measuring serum MDA, respectively. We divided the patients into two groups according to the existence of comets appearing in the comet assay. Group 1 included 44 patients with negative assay results and group 2 consisted of seven patients with positive comet assay findings. We compared the age, gender proportion, PSG data (respiratory disturbance index [RDI], lowest O2 saturation level, and arousal index [AI]), time of disease onset, smoking habits, and serum MDA levels between the two groups.ResultsThe average age and gender proportion of the two groups were not statistically different (P>0.05). The average of RDI for group 1 was 30.4±18.4 and 8.0±7.7 (P0.05). No relationship between positive comet assay results and OSAS severity was identified.ConclusionResults of the current study showed that OSAS was not associated with DNA damage as measured by comet assays or oxidative stress according to serum MDA levels

Anatomical evaluation of CT-MRI combined femoral model

<p>Abstract</p> <p>Background</p> <p>Both CT and MRI are complementary to each other in that CT can produce a distinct contour of bones, and MRI can show the shape of both ligaments and bones. It will be ideal to build a CT-MRI combined model to take advantage of complementary information of each modality. This study evaluated the accuracy of the combined femoral model in terms of anatomical inspection.</p> <p>Methods</p> <p>Six normal porcine femora (180 ± 10 days, 3 lefts and 3 rights) with ball markers were scanned by CT and MRI. The 3D/3D registration was performed by two methods, i.e. the landmark-based 3 points-to-3 points and the surface matching using the iterative closest point (ICP) algorithm. The matching accuracy of the combined model was evaluated with statistical global deviation and locally measure anatomical contour-based deviation. Statistical analysis to assess any significant difference between accuracies of those two methods was performed using univariate repeated measures ANOVA with the Turkey post hoc test.</p> <p>Results</p> <p>This study revealed that the local 2D contour-based measurement of matching deviation was 0.5 ± 0.3 mm in the femoral condyle, and in the middle femoral shaft. The global 3D contour matching deviation of the landmark-based matching was 1.1 ± 0.3 mm, but local 2D contour deviation through anatomical inspection was much larger as much as 3.0 ± 1.8 mm.</p> <p>Conclusion</p> <p>Even with human-factor derived errors accumulated from segmentation of MRI images, and limited image quality, the matching accuracy of CT-&-MRI combined 3D models was 0.5 ± 0.3 mm in terms of local anatomical inspection.</p

Comparison of Component-Resolved Diagnosis by Using Allergen Microarray With the Conventional Tests in Allergic Rhinitis Patients: The First Using in Korea

ObjectivesThe aim of this study was to evaluate the component-resolved diagnosis using a microarray allergen chip (Immuno Solid-phase Allergen Chip, ImmunoCAP ISAC) and to compare this new diagnostic tool with the established ImmunoCAP methods for allergen-specific IgE detection in allergic rhinitis patients.MethodsOne hundred sixty-eight allergic rhinitis patients were included in this study. All the patients were diagnosed with allergic rhinitis according to their clinical symptoms, physical examination and a positive skin prick test. We analyzed their specific IgEs for house dust mites (Dermatophagoides farine [DF] and Dermatophagoides pteronyssinus [DP]), Alternaria alternata, birch, and mugwort using ImmunoCAP and ImmunoCAP ISAC in the same patient sample. We compared the sensitivity and correlation between the two tests.ResultsIn cases of allergies to DP and DF, the sensitivity of the specific IgE was 80% and that of the allergen microarray was 78.9%. The correlation between the two tests was significant for both DP and DF (P<0.001). For the A. alternata, birch and mugwort allergens, the sensitivity of ImmunoCAP ISAC was slightly lower than that of ImmunoCAP.ConclusionThese results suggest that the allergen microarray chip method is a reliable new method to diagnose the components of an allergen in patients with allergic rhinitis sensitive to house dust mites. Further study about the utility of the allergen microarray is needed

Comparison between a reanalyzed product by 3-dimensional variational assimilation technique and observations in the Ulleung Basin of the East/Japan Sea

Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Marine Systems 78 (2009): 249-264, doi:10.1016/j.jmarsys.2009.02.017.Reanalyzed products from a MOM3-based East Sea Regional Ocean Model with a 3- dimentional variational data assimilation module (DA-ESROM), have been compared with the observed hydrographic and current datasets in the Ulleung Basin (UB) of the East/Japan Sea (EJS). Satellite-borne sea surface temperature and sea surface height data, and in-situ temperature profiles have been assimilated into the DA-ESROM. The performance of the DA-ESROM appears to be efficient enough to be used in an operational ocean forecast system. Comparing with the results from Mitchell et al. (2005a), the DA-ESROM fairly well simulates the high variability of the Ulleung Warm Eddy and Dok Cold Eddy as well as the branching of the Tsushima Warm Current in the UB. The overall root-mean-square error between 100m temperature field reproduced by the DA-ESROM and the observed 100-dbar temperature field is 2.1°C, and the spatially averaged grid-to-grid correlation between the two temperature fields is high with a mean value of 0.79 for the intercomparison period. The DA-ESROM reproduces the development of strong southward North Korean Cold Current (NKCC) in summer consistent with the observational results, which is thought to be an improvement of the previous numerical models in the EJS. The reanalyzed products show that the NKCC is about 35 km wide, and flows southward along the Korean coast from spring to summer with maximum monthly mean volume transport of about 0.8 Sv in August-September.The major part of this works was conducted with financial support by Agency for Defense Development under the contract UD031003AD. The first and seventh authors were supported at the final stage of this work by KORDI’s research projects (PE9830Q and PG47100). The second author was supported by EAST-I Program of the Ministry of Maritime Affairs and Fisheries

Delayed Treatment of Zygomatic Tetrapod Fracture

Since maxillofacial injury is frequently accompanied by other diseases, its evaluation and treatment are open delayed. When the evaluation is delayed, the surgical treatment can be difficult or impossible. A 21-yr-old man presented with right facial swelling and deformity after injury. We planned immediate surgical repair for his right tetrapod fracture, but the operation was delayed for two months due to severe hyperthyroidism. During the operation, we reducted and fixed the deviated bone after refracture of the zygomatic arch with an osteotome to achieve mobility. The facial deformity and difficulty in mouth opening were improved after the operation. Even in the presence of accompanying fractures, early evaluation and proper management can prevent complications and achieve acceptable cosmetic outcomes in maxillofacial trauma patients. In patients with malunion of fracture sites, fixation after refracture using an osteotome can be a good treatment option for obtaining good mobility