Korea Pathfinder Lunar Orbiter Flight Dynamics Simulation and Rehearsal Results for Its Operational Readiness Checkout

Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, was successfully launched on 4 Aug. from Cape Canaveral Space Force Station using a Space-X Falcon-9 rocket. Flight dynamics (FD) operational readiness was one of the critical parts to be checked before the flight. To demonstrate FD software’s readiness and enhance the operator’s contingency response capabilities, KPLO FD specialists planned, organized, and conducted four simulations and two rehearsals before the KPLO launch. For the efficiency and integrity of FD simulation and rehearsal, different sets of blind test data were prepared, including the simulated tracking measurements that incorporated dynamical model errors, maneuver execution errors, and other errors associated with a tracking system. This paper presents the simulation and rehearsal results with lessons learned for the KPLO FD operational readiness checkout. As a result, every functionality of FD operation systems is firmly secured based on the operation procedure with an enhancement of contingency operational response capability. After conducting several simulations and rehearsals, KPLO FD specialists were much more confident in the flight teams’ ability to overcome the challenges in a realistic flight and FD software’s reliability in flying the KPLO. Moreover, the results of this work will provide numerous insights to the FD experts willing to prepare deep space flight operations

Color-stable, ITO-free white organic light-emitting diodes with enhanced efficiency using solution-processed transparent electrodes and optical outcoupling layers

In this work, we demonstrate color-stable, ITO-free white organic light-emitting diodes (WOLEDs) with enhanced efficiencies by combining the high-conductivity conducting polymer PEDOT:PSS as transparent electrode and a nanoparticle-based scattering layer (NPSL) as the effective optical out-coupling layer. In addition to efficiency enhancement, the NPSL is also beneficial to the stabilization of electroluminescent spectra/colors over viewing angles. Both the PEDOT:PSS and the NPSL can be fabricated by simple, low-temperature solution processing. The integration of both solution-processable transparent electrodes and light extraction structures into OLEDs is particularly attractive for applications since they simultaneously provide manufacturing, cost and efficiency advantages. PostprintPeer reviewe

HLAscan: genotyping of the HLA region using next-generation sequencing data

Background Several recent studies showed that next-generation sequencing (NGS)-based human leukocyte antigen (HLA) typing is a feasible and promising technique for variant calling of highly polymorphic regions. To date, however, no method with sufficient read depth has completely solved the allele phasing issue. In this study, we developed a new method (HLAscan) for HLA genotyping using NGS data. Results HLAscan performs alignment of reads to HLA sequences from the international ImMunoGeneTics project/human leukocyte antigen (IMGT/HLA) database. The distribution of aligned reads was used to calculate a score function to determine correctly phased alleles by progressively removing false-positive alleles. Comparative HLA typing tests using public datasets from the 1000 Genomes Project and the International HapMap Project demonstrated that HLAscan could perform HLA typing more accurately than previously reported NGS-based methods such as HLAreporter and PHLAT. In addition, the results of HLA-A, −B, and -DRB1 typing by HLAscan using data generated by NextGen were identical to those obtained using a Sanger sequencing–based method. We also applied HLAscan to a family dataset with various coverage depths generated on the Illumina HiSeq X-TEN platform. HLAscan identified allele types of HLA-A, −B, −C, −DQB1, and -DRB1 with 100% accuracy for sequences at ≥ 90× depth, and the overall accuracy was 96.9%. Conclusions HLAscan, an alignment-based program that takes read distribution into account to determine true allele types, outperformed previously developed HLA typing tools. Therefore, HLAscan can be reliably applied for determination of HLA type across the whole-genome, exome, and target sequences

Deep Multilayer Brain Proteomics Identifies Molecular Networks in Alzheimer\u27s Disease Progression

Alzheimer\u27s disease (AD) displays a long asymptomatic stage before dementia. We characterize AD stage-associated molecular networks by profiling 14,513 proteins and 34,173 phosphosites in the human brain with mass spectrometry, highlighting 173 protein changes in 17 pathways. The altered proteins are validated in two independent cohorts, showing partial RNA dependency. Comparisons of brain tissue and cerebrospinal fluid proteomes reveal biomarker candidates. Combining with 5xFAD mouse analysis, we determine 15 Aβ-correlated proteins (e.g., MDK, NTN1, SMOC1, SLIT2, and HTRA1). 5xFAD shows a proteomic signature similar to symptomatic AD but exhibits activation of autophagy and interferon response and lacks human-specific deleterious events, such as downregulation of neurotrophic factors and synaptic proteins. Multi-omics integration prioritizes AD-related molecules and pathways, including amyloid cascade, inflammation, complement, WNT signaling, TGF-β and BMP signaling, lipid metabolism, iron homeostasis, and membrane transport. Some Aβ-correlated proteins are colocalized with amyloid plaques. Thus, the multilayer omics approach identifies protein networks during AD progression

Effect of Cr Addition on Magnetic Properties and Corrosion Resistance of Optimized Co and Fe-Based Amorphous Alloys

In the Fe-Co alloy system, the addition of Cr improves the glass-forming ability (GFA) with superior soft magnetic properties such as high saturation magnetization (Ms) and low coercivity (Hc). In addition, Cr is considered to be an important factor for improving the corrosion resistance of Fe-based amorphous alloy. Therefore, in the present study, we investigated the GFA, soft magnetic properties, and corrosion resistance of the as-spun ribbons in [Co0.075Fe0.675B0.2Si0.05]100−xCrx (x = 0–8) alloy system. The ribbons were produced using the melt-spinning technique and were characterized by X-ray diffraction, differential scanning calorimetry, thermomechanical analysis, and vibrating sample magnetometer. The Co-Fe-B-Si-Cr alloys exhibited high thermal stability and a high Ms of 0.93–1.53 T. Corrosion properties were evaluated by cyclic voltammetry. The addition of Cr improved the corrosion resistance of the alloys. The alloys with a higher Cr content exhibited a higher corrosion resistance. The optimum combination with soft magnetic properties and corrosion resistance of Fe-co based amorphous alloys can be utilized for extensive fields of application through a variation of Cr contents

Detection of apneic events from single channel nasal airflow using 2nd derivative method

Detection of sleep apnea is one of the major tasks in sleep studies. Several methods, analyzing the various features of bio-signals, have been applied for automatic detection of sleep apnea, but it is still required to detect apneic events efficiently and robustly from a single nasal airflow signal under varying situations. This study introduces a new algorithm that analyzes the nasal airflow (NAF) for the detection of obstructive apneic events. It is based on mean magnitude of the second derivatives (MMSD) of NAF, which can detect respiration strength robustly under offset or baseline drift. Normal breathing epochs are extracted automatically by examining the stability of SaO(2) and NAF regularity for each subject. The standard MMSD and period of NAF, which are regarded as the values at the normal respiration level, are determined from the normal breathing epochs. In this study, 24 Polysomnography (PSG) recordings diagnosed as obstructive sleep apnea (OSA) syndrome were analyzed. By analyzing the mean performance of the algorithm in a training set consisting of three PSG recordings, apnea threshold is determined to be 13% of the normal MMSD of NAF. NAF signal was divided into 1-s segments for analysis. Each segment is compared with the apnea threshold and classified into apnea events if the segment is included in a group of apnea segments and the group satisfies the time limitation. The suggested algorithm was applied to a test set consisting of the other 21 PSG recordings. Performance of the algorithm was evaluated by comparing the results with the sleep specialist's manual scoring on the same record. The overall agreement rate between the two was 92.0% (kappa=0.78). Considering its simplicity and lower computational load, the suggested algorithm is found to be robust and useful. It is expected to assist sleep specialists to read PSG more quickly and will be useful for ambulatory monitoring of apneas using airflow signals.This work was supported by the Korean Science and Engineering Foundation under the Advanced Biometric Research Center Program

Overview of the Flight Dynamics Subsystem for Korea Pathfinder Lunar Orbiter Mission

Korea’s first lunar mission, the Korea Pathfinder Lunar Orbiter (KPLO), aims to launch in mid-2022 via the Space-X Falcon-9 launch vehicle. For the successful flight operation of KPLO, the Korea Aerospace Research Institute (KARI) has designed and developed the Flight Dynamics Subsystem (FDS). FDS is one of the subsystems in the KPLO Deep-Space Ground System (KDGS), which is responsible for the overall flight dynamics-related operation. FDS is currently successfully implemented and meets all of the requirements derived from the critical design phases. The current work addresses the design and implementation results for the KPLO FDS. Starting from overviews on KPLO payloads, bus systems, and mission trajectory characteristics, a review on KDGS is also treated briefly. Details on the design philosophy, unique characteristics, and functionalities of all six different modules nested inside the FDS with its Graphical User Interface (GUI) design are discussed. Moreover, efforts currently devoted to the flight operation preparation of the KPLO are summarized, including many collaborative works between KARI and the National Aeronautics and Space Administration (NASA) teams