The US-ROK Alliance: the Feasibility of the Continuing US Military Presence in the Republic of Korea

The U.S. – ROK alliance is currently on a high after a decade of fluctuating relations. Both the Obama and Lee administrations have been focused on producing a future plan that takes both nations strategic interests into account while also considering the changing dynamics in the region. The alliance partners have had to overcome differences of opinion on foreign policy, the rise of anti-Americanism in South Korea, the emergence of China as a power in the region, and the continuing nuclear ambitions and instability in North Korea. This paper discusses how the realignment of the force command structure and a unified long-term strategic plan, has effectively modified the USFK to better deal with these wide ranging issues and remain a force of strategic relevance now and in the future of Asia. The USFK therefore remains an important part of the U.S. – ROK alliance that has positive security implications for both the Korean Peninsula and its surrounding region. It has also become the catalyst for stronger all-round relations between the long-time allies, which lead to positive flow-on effects in economic matters such as the U.S. – ROK Free-Trade Agreement (KORUS FTA)

Ergonomic Evaluation and Design Process for Healthcare Products: A Case Study of Patient Transfer Design

Department of Human Factors EngineeringInpatient falls are a critical issue in healthcare facilities. Up to 30% of such falls result in injury, which may in turn lead to impaired rehabilitation and co-morbidity in mental and physical health. One of routine activities that poses high risks of falls of patients is a within-facility patient transfer. Within-facility patient transfer is a high-risk task not only for patients but also for care-givers. Care-givers frequently transfer patients from bed to a wheelchair or wheelchair to bed manually, and it can cause musculoskeletal injuries of the care-giver. Various aid devices such as a powered patient lifter have been introduced to improve the safety of patient transfer and to assist care-givers, but they have not been widely used due to their bulky size and slow operation. To overcome such problems, one of medical robot manufacturers in Korea developed the functional prototype of a semi-powered patient lift and transportation device. The device is equipped with a forward leaning seat to allow easy loading and unloading patients without manual lifting. Since the functionality and usability of the prototype has not been evaluated, it was necessary to conduct thorough evaluation both in fields and laboratory and to come up with redesign goals and strategies. Therefore, this study was aimed to evaluate the functionality and usability of the prototype using various ergonomic evaluation approaches and to redesign the prototype based on the results of the evaluation. In the evaluation process, various methods have been used to understand and identify care-givers??? needs, interaction patterns between the prototype and patients, and safety issues when operating the prototype inside and outside patient rooms through user interview and field observation studies at hospitals. To evaluate the biomechanical advantages over traditional manual transfer methods, a human-subject experiment was also conducted with quantitative assessment of muscle activities, foot reaction forces and transfer time. Then, using the findings of the evaluation, redesign ideas have been made and the prototype has been upgraded to reflect the ideas. The upgraded prototype was evaluated again at hospitals to confirm whether the changes improved the functionality and usability of the device. In this paper, detail procedures for the evaluation and redesign are explained, with related problems and challenges. Also, some ideas for improving the evaluation/redesign processes for healthcare products are proposed for future research and development.ope

Accelerating Sampling and Aggregation Operations in GNN Frameworks with GPU Initiated Direct Storage Accesses

Graph Neural Networks (GNNs) are emerging as a powerful tool for learning from graph-structured data and performing sophisticated inference tasks in various application domains. Although GNNs have been shown to be effective on modest-sized graphs, training them on large-scale graphs remains a significant challenge due to lack of efficient data access and data movement methods. Existing frameworks for training GNNs use CPUs for graph sampling and feature aggregation, while the training and updating of model weights are executed on GPUs. However, our in-depth profiling shows the CPUs cannot achieve the throughput required to saturate GNN model training throughput, causing gross under-utilization of expensive GPU resources. Furthermore, when the graph and its embeddings do not fit in the CPU memory, the overhead introduced by the operating system, say for handling page-faults, comes in the critical path of execution. To address these issues, we propose the GPU Initiated Direct Storage Access (GIDS) dataloader, to enable GPU-oriented GNN training for large-scale graphs while efficiently utilizing all hardware resources, such as CPU memory, storage, and GPU memory with a hybrid data placement strategy. By enabling GPU threads to fetch feature vectors directly from storage, GIDS dataloader solves the memory capacity problem for GPU-oriented GNN training. Moreover, GIDS dataloader leverages GPU parallelism to tolerate storage latency and eliminates expensive page-fault overhead. Doing so enables us to design novel optimizations for exploiting locality and increasing effective bandwidth for GNN training. Our evaluation using a single GPU on terabyte-scale GNN datasets shows that GIDS dataloader accelerates the overall DGL GNN training pipeline by up to 392X when compared to the current, state-of-the-art DGL dataloader.Comment: Under Submission. Source code: https://github.com/jeongminpark417/GID

Quantum Conductance Probing of Oxygen Vacancies in SrTiO3 Epitaxial Thin Film Using Graphene

The quantum Hall conductance in monolayer graphene on an epitaxial SrTiO3 (STO) thin film is studied to understand the role of oxygen vacancies in determining the dielectric properties of STO. As the gate voltage sweep range is gradually increased in our device, we observe systematic generation and annihilation of oxygen vacancies evidenced from the hysteretic conductance behavior in graphene. Furthermore, based on the experimentally observed linear scaling relation between the effective capacitance and the voltage sweep range, a simple model is constructed to manifest the relationship among the dielectric properties of STO with oxygen vacancies. The inherent quantum Hall conductance in graphene can be considered as a sensitive, robust, and non-invasive probe for understanding the electronic and ionic phenomena in complex transition metal oxides without impairing the oxide layer underneath.Comment: 21 pages, 4 figures, 2 supp. figure

Hydrogen-bond structure and low-frequency dynamics of electrolyte solutions: Hydration numbers from ab Initio water reorientation dynamics and dielectric relaxation spectroscopy

We present an atomistic simulation scheme for the determination of the hydration number (h) of aqueous electrolyte solutions based on the calculation of the water dipole reorientation dynamics. In this methodology, the time evolution of an aqueous electrolyte solution generated from ab initio molecular dynamics simulations is used to compute the reorientation time of different water subpopulations. The value of h is determined by considering whether the reorientation time of the water subpopulations is retarded with respect to bulk-like behavior. The application of this computational protocol to magnesium chloride (MgCl2 ) solutions at different concentrations (0.6-2.8 mol kg-1 ) gives h values in excellent agreement with experimental hydration numbers obtained using GHz-to-THz dielectric relaxation spectroscopy. This methodology is attractive because it is based on a well-defined criterion for the definition of hydration number and provides a link with the molecular-level processes responsible for affecting bulk solution behavior. Analysis of the ab initio molecular dynamics trajectories using radial distribution functions, hydrogen bonding statistics, vibrational density of states, water-water hydrogen bonding lifetimes, and water dipole reorientation reveals that MgCl2 has a considerable influence on the hydrogen bond network compared with bulk water. These effects have been assigned to the specific strong Mg-water interaction rather than the Cl-water interaction

GSK-3β inhibition by curcumin mitigates amyloidogenesis via TFEB activation and anti-oxidative activity in human neuroblastoma cells

© 2020 Informa UK Limited, trading as Taylor & Francis Group.The translocation of transcription factor EB (TFEB) to the nucleus plays a pivotal role in the regulation of basic cellular processes, such as lysosome biogenesis and autophagy. Autophagy is an intracellular degradation system that delivers cytoplasmic constituents to the lysosome, which is important in maintaining cellular homeostasis during environmental stress. Furthermore, oxidative stress is a critical cause for the progression of neurodegenerative diseases. Curcumin has anti-oxidative and anti-inflammatory activities, and is expected to have potential therapeutic effects in various diseases. In this study, we demonstrated that curcumin regulated TFEB export signalling via inhibition of glycogen synthase kinase-3β (GSK-3β); GSK-3β was inactivated by curcumin, leading to reduced phosphorylation of TFEB. We further showed that H2O2-induced oxidative stress was reduced by curcumin via the Nrf2/HO-1 pathway in human neuroblastoma cells. In addition, we showed that curcumin induced the degradation of amyloidogenic proteins, including amyloid-β precursor protein and α-synuclein, through the TFEB-autophagy/lysosomal pathway. In conclusion, curcumin regulates autophagy by controlling TFEB through the inhibition of GSK-3β, and increases antioxidant gene expression in human neuroblastoma cells. These results contribute to the development of novel cellular therapies for neurodegenerative diseases.

CO ameliorates cellular senescence and aging by modulating the miR-34a/Sirt1 pathway

Oxidative stress is recognised as a key factor that can lead to cellular senescence and aging. Carbon monoxide (CO) is produced by haemoxygenase-1 (HO-1), which exerts cytoprotective effects in aging-related diseases, whereas the effect of CO on cellular senescence and aging has not been elucidated. In the current study, we clearly demonstrated that CO delays the process of cellular senescence and aging through regulation of miR-34a and Sirt1 expression. CO reduced H2O2-induced premature senescence in human diploid fibroblast WI-38 cells measured with SA-beta-Gal-staining. Furthermore, CO significantly decreased the expression of senescence-associated secretory phenotype (SASP), including TNF-alpha IL-6, and PAI-1 and increased the transcriptional levels of antioxidant genes, such as HO-1 and NQO1. Moreover, CO apparently enhanced the expression of Sirt1 through down-regulation of miR-34a. Next, to determine whether Sirt1 mediates the inhibitory effect of CO on cellular senescence, we pre-treated WI-38 cells with the Sirt1 inhibitor Ex527 and a miR-34a mimic followed by the administration of H2O2 and evaluated the expression of SASP and antioxidant genes as well as ROS production. According to our results, Sirt1 is crucial for the antiaging and antioxidant effects of CO. Finally, CO prolonged the lifespan of Caenorhabditis elegans and delayed high-fat diet-induced liver aging. Taken together, these findings demonstrate that CO reduces cellular senescence and liver aging through the regulation of miR-34a and Sirt1.