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Abstract The far-UVC (222 nm) system has emerged as a solution for controlling airborne transmission, yet its effect on indoor air quality, particularly concerning positioning, remains understudied. In this study, we examined the impact of far-UVC lamp position on the disinfection and secondary contaminant formation in a small office. We employed a three-dimensional computational fluid dynamics (CFD) model to integrate UV intensity fields formed by different lamp positions (ceiling-mounted, wall-mounted, and stand-alone types) along with the air quality model. Our findings reveal that the ceiling-mounted type reduces human exposure to airborne pathogens by up to 80% compared to scenarios without far-UVC. For all the lamp positions, O3 concentration in the breathing zone increases by 4–6 ppb after one hour of operation. However, it should be noted that a high concentration zone (> 25 ppb) forms near the lamp when it is turned on. Moreover, ventilation plays a crucial role in determining human exposure to airborne pathogens and secondary contaminants. Increasing the ventilation rate from 0.7 h−1 to 4 h−1 reduces airborne pathogen and secondary contaminant concentrations by up to 90%. However, caution is warranted as higher ventilation rates can lead to elevated O3 indoors, especially under conditions of high outdoor O3 concentrations.

Abstract 3D printing has been widely used for on-demand prototyping of complex three-dimensional structures. In biomedical applications, PEDOT:PSS has emerged as a promising material in versatile bioelectronics due to its tissue-like mechanical properties and suitable electrical properties. However, previously developed PEDOT:PSS inks have not been able to fully utilize the advantages of commercial 3D printing due to its long post treatment times, difficulty in high aspect ratio printing, and low conductivity. We propose a one-shot strategy for the fabrication of PEDOT:PSS ink that is able to simultaneously achieve on-demand biocompatibility (no post treatment), structural integrity during 3D printing for tall three-dimensional structures, and high conductivity for rapid-prototyping. By using ionic liquid-facilitated PEDOT:PSS colloidal stacking induced by a centrifugal protocol, a viscoplastic PEDOT:PSS-ionic liquid colloidal (PILC) ink was developed. PILC inks exhibit high-aspect ratio vertical stacking, omnidirectional printability for generating suspended architectures, high conductivity (~286 S/cm), and high-resolution printing (~50 µm). We demonstrate the on-demand and versatile applicability of PILC inks through the fabrication of 3D circuit boards, on-skin physiological signal monitoring e-tattoos, and implantable bioelectronics (opto-electrocorticography recording, low voltage sciatic nerve stimulation and recording from deeper brain layers via 3D vertical spike arrays).

Abstract Ensuring stable integration of diverse soft electronic components for reliable operation under dynamic conditions is crucial. However, integrating soft electronics, comprising various materials like polymers, metals, and hydrogels, poses challenges due to their different mechanical and chemical properties. This study introduces a dried-hydrogel adhesive made of poly(vinyl alcohol) and tannic acid multilayers (d-HAPT), which integrates soft electronic materials through moisture-derived chain entanglement. d-HAPT is a thin (~1 µm) and highly transparent (over 85% transmittance in the visible light region) adhesive, showing robust bonding (up to 3.6 MPa) within a short time (

Abstract Background Corydalis DC., the largest genus in the family Papaveraceae, comprises > 465 species. Complete plastid genomes (plastomes) of Corydalis show evolutionary changes, including syntenic arrangements, gene losses and duplications, and IR boundary shifts. However, little is known about the evolution of the mitochondrial genome (mitogenome) in Corydalis. Both the organelle genomes and transcriptomes are needed to better understand the relationships between the patterns of evolution in mitochondrial and plastid genomes. Results We obtained complete plastid and mitochondrial genomes from Corydalis pauciovulata using a hybrid assembly of Illumina and Oxford Nanopore Technologies reads to assess the evolutionary parallels between the organelle genomes. The mitogenome and plastome of C. pauciovulata had sizes of 675,483 bp and 185,814 bp, respectively. Three ancestral gene clusters were missing from the mitogenome, and expanded IR (46,060 bp) and miniaturized SSC (202 bp) regions were identified in the plastome. The mitogenome and plastome of C. pauciovulata contained 41 and 67 protein-coding genes, respectively; the loss of genes was a plastid-specific event. We also generated a draft genome and transcriptome for C. pauciovulata. A combination of genomic and transcriptomic data supported the functional replacement of acetyl-CoA carboxylase subunit β (accD) by intracellular transfer to the nucleus in C. pauciovulata. In contrast, our analyses suggested a concurrent loss of the NADH-plastoquinone oxidoreductase (ndh) complex in both the nuclear and plastid genomes. Finally, we performed genomic and transcriptomic analyses to characterize DNA replication, recombination, and repair (DNA-RRR) genes in C. pauciovulata as well as the transcriptomes of Liriodendron tulipifera and Nelumbo nuicifera. We obtained 25 DNA-RRR genes and identified their structure in C. pauciovulata. Pairwise comparisons of nonsynonymous (d N) and synonymous (d S) substitution rates revealed that several DNA-RRR genes in C. pauciovulata have higher d N and d S values than those in N. nuicifera. Conclusions The C. pauciovulata genomic data generated here provide a valuable resource for understanding the evolution of Corydalis organelle genomes. The first mitogenome of Papaveraceae provides an example that can be explored by other researchers sequencing the mitogenomes of related plants. Our results also provide fundamental information about DNA-RRR genes in Corydalis and their related rate variation, which elucidates the relationships between DNA-RRR genes and organelle genome stability.

Abstract Abies koreana E.H.Wilson is an endangered evergreen coniferous tree that is native to high altitudes in South Korea and susceptible to the effects of climate change. Hybridization and reticulate evolution have been reported in the genus; therefore, multigene datasets from nuclear and cytoplasmic genomes are needed to better understand its evolutionary history. Using the Illumina NovaSeq 6000 and Oxford Nanopore Technologies (ONT) PromethION platforms, we generated complete mitochondrial (1,174,803 bp) and plastid (121,341 bp) genomes from A. koreana. The mitochondrial genome is highly dynamic, transitioning from cis- to trans-splicing and breaking conserved gene clusters. In the plastome, the ONT reads revealed two structural conformations of A. koreana. The short inverted repeats (1186 bp) of the A. koreana plastome are associated with different structural types. Transcriptomic sequencing revealed 1356 sites of C-to-U RNA editing in the 41 mitochondrial genes. Using A. koreana as a reference, we additionally produced nuclear and organelle genomic sequences from eight Abies species and generated multiple datasets for maximum likelihood and network analyses. Three sections (Balsamea, Momi, and Pseudopicea) were well grouped in the nuclear phylogeny, but the phylogenomic relationships showed conflicting signals in the mitochondrial and plastid genomes, indicating a complicated evolutionary history that may have included introgressive hybridization. The obtained data illustrate that phylogenomic analyses based on sequences from differently inherited organelle genomes have resulted in conflicting trees. Organelle capture, organelle genome recombination, and incomplete lineage sorting in an ancestral heteroplasmic individual can contribute to phylogenomic discordance. We provide strong support for the relationships within Abies and new insights into the phylogenomic complexity of this genus.

Bond resistance is critical for reinforcing fibers in cementitious materials. Recently, crimped shape memory alloy fibers (SMA) have been raised as candidates for providing abundant benefits such as improved strength, enhanced durability, and crack closing. This study aimed to examine the influence of wave-depth and wave-length of crimped SMA fibers on their bond behavior. The crimped fibers in this study were categorized in four groups based on the wave-length. Each group had four types of fibers that considered the ratio of wave-depth to wave-length (DLR). Thus, a total of sixteen types of fibers were prepared with variations in wave-length and wave-depth. The tensile test used bare crimped SMA fibers, while the pullout tests used half dog-bone specimens. After the tests, the finite element model was used to evaluate the interaction parameters that were difficult to measure in the experience test. The results showed that the fibers with the smallest wave-length showed the largest maximum bond resistance in the same dept-to-length ratio (DLR) group, and that values decreased with an increasing wave-length. In addition, the smallest wave-length fibers demonstrated the most effective stiffness. Furthermore, the finite element analysis discovered that the geometric friction coefficients of the crimped SMA fibers were affected significantly by the geometric variation. The longer wave-length fiber revealed the larger estimated frictional coefficient.

Conventional DNN inference accelerators are designed with a few (up to four) large systolic arrays. As such a scale-up architecture often suffers from low utilization, a scale-out architecture, in which a single accelerator has tens of pods and each pod has a small systolic array, has been proposed. While the scale-out architecture is promising, it still incurs increasing off-chip memory access as the pods are supposed to access the duplicate tiles of tensors. Prior work has proposed a shared buffer structure to address the problem, but those architectures suffer from performance degradation due to shared buffer access latency. We make an observation that all the pods access the same rows of input and weights within a short time window. With the observation, we propose a new inference accelerator architecture, called Vectored Systolic Arrays (SAVector). SAVector consists of a new two-level on-chip buffer architecture and a tensor tile scheduling technique. In the new buffer architecture, global buffers are shared by all the pods and they keep the rows shared by the pods. And each pod has a tiny dedicated buffer. SAVector monitors the memory access behavior and timely determines to prefetch the data and flush it. In our evaluation, SAVector exhibits a very similar off-chip memory access count to the scale-up architecture and achieves 52% energy-delay-product (EDP) reduction. Also, SAVector achieves 27% EDP reduction over prior work by mitigating performance degradation from global buffer access latency.

Abstract Deformable semi-solid liquid metal particles (LMP) have emerged as a promising substitute for rigid conductive fillers due to their excellent electrical properties and stable conductance under strain. However, achieving a compact and robust coating of LMP on fibers remains a persistent challenge, mainly due to the incompatibility of conventional coating techniques with LMP. Additionally, the limited durability and absence of initial electrical conductivity of LMP restrict their widespread application. In this study, we propose a solution process that robustly and compactly assembles mechanically durable and initially conductive LMP on fibers. Specifically, we present a shearing-based deposition of polymer-attached LMP followed by additional coating with CNT-attached LMP to create bi-layer LMP composite with exceptional durability, electrical conductivity, stretchability, and biocompatibility on various fibers. The versatility and reliability of this manufacturing strategy for 1D electronics are demonstrated through the development of sewn electrical circuits, smart clothes, stretchable biointerfaced fiber, and multifunctional fiber probes.

IntroductionDuring plant evolution, intracellular DNA transfer (IDT) occurs not only from organelles to the nucleus but also between organelles. To further comprehend these events, both organelle genomes and transcriptomes are needed.MethodsIn this study, we constructed organelle genomes and transcriptomes for two Dystaenia species and described their dynamic IDTs between their nuclear and mitochondrial genomes, or plastid and mitochondrial genomes (plastome and mitogenome).Results and DiscussionWe identified the putative functional transfers of the mitochondrial genes 5′ rpl2, rps10, rps14, rps19, and sdh3 to the nucleus in both Dystaenia species and detected two transcripts for the rpl2 and sdh3 genes. Additional transcriptomes from the Apicaceae species also provided evidence for the transfers and duplications of these mitochondrial genes, showing lineage-specific patterns. Intrageneric variations of the IDT were found between the Dystaenia organelle genomes. Recurrent plastid-to-mitochondrion DNA transfer events were only identified in the D. takeshimana mitogenome, and a pair of mitochondrial DNAs of plastid origin (MIPTs) may generate minor alternative isoforms. We only found a mitochondrion-to-plastid DNA transfer event in the D. ibukiensis plastome. This event may be linked to inverted repeat boundary shifts in its plastome. We inferred that the insertion region involved an MIPT that had already acquired a plastid sequence in its mitogenome via IDT. We propose that the MIPT acts as a homologous region pairing between the donor and recipient sequences. Our results provide insight into the evolution of organelle genomes across the family Apiaceae.

Abstract Over the past decade, conductive hydrogels have received great attention as tissue-interfacing electrodes due to their soft and tissue-like mechanical properties. However, a trade-off between robust tissue-like mechanical properties and good electrical properties has prevented the fabrication of a tough, highly conductive hydrogel and limited its use in bioelectronics. Here, we report a synthetic method for the realization of highly conductive and mechanically tough hydrogels with tissue-like modulus. We employed a template-directed assembly method, enabling the arrangement of a disorder-free, highly-conductive nanofibrous conductive network inside a highly stretchable, hydrated network. The resultant hydrogel exhibits ideal electrical and mechanical properties as a tissue-interfacing material. Furthermore, it can provide tough adhesion (800 J/m2) with diverse dynamic wet tissue after chemical activation. This hydrogel enables suture-free and adhesive-free, high-performance hydrogel bioelectronics. We successfully demonstrated ultra-low voltage neuromodulation and high-quality epicardial electrocardiogram (ECG) signal recording based on in vivo animal models. This template-directed assembly method provides a platform for hydrogel interfaces for various bioelectronic applications.

Renewable energy sources are being increasingly deployed to achieve carbon neutrality, thereby boosting photovoltaic (PV) system adoptions. Accordingly, vertical PV systems designed for specific installations have been developed. We propose a strategy to enhance the PV hosting capacity of a connected distribution line (DL) by combining vertical installations with modules facing east-west and conventional PV systems with modules facing south at an installation angle of approximately 30°. The data were obtained from a real testbed located in South Korea, which is situated in a mid-latitude region. We analyzed the generation patterns of vertical and combined PV systems (vertical and conventional) to enhance the hosting capacity. The results showed that vertical PV combination ratios of 40–60% effectively flattened the peak generation curve. Additionally, the DL hosting capacity improved by 40% under real-world conditions. In an actual industrial scenario, the system feasibility was validated to be within the voltage maintenance range and thermal capacity of lines in South Korea, indicating that this approach can mitigate the need for additional line installations and renewable energy curtailments. Furthermore, the issue of Duck Curves in the power grid can be addressed by smoothing the power production of the PV systems, particularly during low-demand periods.

Abstract In this review, p‐type doping technologies for organic/polymeric semiconductors in hole transporting layer (HTL) for perovskite solar cells (PSCs) are examined. Initially, we investigate the conventional dopant systems used for HTL in terms of dopants and additives, as well as their doping principles and limitations. Second, we recapitulate the current research strategies for overcoming the limitations of conventional dopant systems: (i) dopants/additives with large cations, (ii) hydrophobic dopants/additives, (iii) locking‐capable dopants/additives, (iv) rinsing or ion exchange methods, and (v) other methods. Afterwards, we provide a comprehensive analysis of alternative dopants based on ionic liquids, Lewis acids, strong acceptors, and others. In addition, the review emphasizes current achievements based on multiple research approaches to diverse hole transporting materials, surface/interfacial treatment, and architectural modification of HTL, and provides a perspective on developments of desirable HTL system for efficient and stable PSCs.

Ischemic stroke-induced neuronal cell death leads to the permanent impairment of brain function. The Fas-mediating extrinsic apoptosis pathway and the cytochrome c-mediating intrinsic apoptosis pathway are two major molecular mechanisms contributing to neuronal injury in ischemic stroke. In this study, we employed a Fas-blocking peptide (FBP) coupled with a positively charged nona-arginine peptide (9R) to form a complex with negatively charged siRNA targeting Bax (FBP9R/siBax). This complex is specifically designed to deliver siRNA to Fas-expressing ischemic brain cells. This complex enables the targeted inhibition of Fas-mediating extrinsic apoptosis pathways and cytochrome c-mediating intrinsic apoptosis pathways. Specifically, the FBP targets the Fas/Fas ligand signaling, while siBax targets Bax involved in mitochondria disruption in the intrinsic pathway. The FBP9R carrier system enables the delivery of functional siRNA to hypoxic cells expressing the Fas receptor on their surface—a finding validated through qPCR and confocal microscopy analyses. Through intranasal (IN) administration of FBP9R/siCy5 to middle cerebral artery occlusion (MCAO) ischemic rat models, brain imaging revealed the complex specifically localized to the Fas-expressing infarcted region but did not localize in the non-infarcted region of the brain. A single IN administration of FBP9R/siBax demonstrated a significant reduction in neuronal cell death by effectively inhibiting Fas signaling and preventing the release of cytochrome c. The targeted delivery of FBP9R/siBax represents a promising alternative strategy for the treatment of brain ischemia.

Apoptosis plays a crucial role in neuronal injury, with substantial evidence implicating Fas-mediated cell death as a key factor in ischemic strokes. To address this, inhibition of Fas-signaling has emerged as a promising strategy in preventing neuronal cell death and alleviating brain ischemia. However, the challenge of overcoming the blood–brain barrier (BBB) hampers the effective delivery of therapeutic drugs to the central nervous system (CNS). In this study, we employed a 30 amino acid-long leptin peptide to facilitate BBB penetration. By conjugating the leptin peptide with a Fas-blocking peptide (FBP) using polyethylene glycol (PEG), we achieved specific accumulation in the Fas-expressing infarction region of the brain following systemic administration. Notably, administration in leptin receptor-deficient db/db mice demonstrated that leptin facilitated the delivery of FBP peptide. We found that the systemic administration of leptin-PEG-FBP effectively inhibited Fas-mediated apoptosis in the ischemic region, resulting in a significant reduction of neuronal cell death, decreased infarct volumes, and accelerated recovery. Importantly, neither leptin nor PEG-FBP influenced apoptotic signaling in brain ischemia. Here, we demonstrate that the systemic delivery of leptin-PEG-FBP presents a promising and viable strategy for treating cerebral ischemic stroke. Our approach not only highlights the therapeutic potential but also emphasizes the importance of overcoming BBB challenges to advance treatments for neurological disorders.

Abstract Background Alzheimer’s disease affects profoundly the quality of human behavior and cognition. The very broad distribution of its severity across various human subjects requires the quantitative diagnose of Alzheimer’s disease beyond the conventional tripartite classification of cohorts such as cognitively normal (CN), mild cognitive impairment (MCI), Alzheimer’s disease (AD). The unfolding of such broad distributions by the quantitative and continuous degree of AD severity is necessary for the precise diagnose in the cross-sectional study of different stages in AD. Results We conducted the massive reanalysis on MRI images of 761 human brains based on the accumulated bigdata of Alzheimer’s Disease Neuroimaging Initiative. The score matrix of cortical thickness profile at cortex points of subjects was constructed by statistically learning the cortical thickness data of 761 human brains. We also developed a new and simple algebraic predictor which provides the quantitative and continuous degree of AD severity of subjects along the scale from 0 for fully CN to 1 for fully AD state. The mathematical measure of a new predictor for the degree of AD severity is presented based on a covariance correlation matrix of cortical thickness profile between human subjects. One can remove the uncertainty in the determination of different stages in AD by the quantitative degree of AD severity and thus go far beyond the tripartite classification of cohorts. Conclusions We unfold the nature of broad distribution of AD severity of subjects even within a given cohort by the scale from 0 for fully CN to 1 for fully AD state. The quantitative and continuous degree of AD severity developed in this study would be a good practical measure for diagnosing the different stages in AD severity.

Abstract Fiber‐based implantable electronics are one of promising candidates for in vivo biomedical applications thanks to their unique structural advantages. However, development of fiber‐based implantable electronic devices with biodegradable capability remains a challenge due to the lack of biodegradable fiber electrodes with high electrical and mechanical properties. Here, a biocompatible and biodegradable fiber electrode which simultaneously exhibits high electrical conductivity and mechanical robustness is presented. The fiber electrode is fabricated through a facile approach that incorporates a large amount of Mo microparticles into outermost volume of a biodegradable polycaprolactone (PCL) fiber scaffold in a concentrated manner. The biodegradable fiber electrode simultaneously exhibits a remarkable electrical performance (≈43.5 Ω cm−1), mechanical robustness, bending stability, and durability for more than 4000 bending cycles based on the Mo/PCL conductive layer and intact PCL core in the fiber electrode. The electrical behavior of the biodegradable fiber electrode under the bending deformation is analyzed by an analytical prediction and a numerical simulation. In addition, the biocompatible properties and degradation behavior of the fiber electrode are systematically investigated. The potential of biodegradable fiber electrode is demonstrated in various applications such as an interconnect, a suturable temperature sensor, and an in vivo electrical stimulator.

Abstract Major earthquakes in continental regions may cause significant damage. Preexisting fault system across megacity receives high attention for possible seismic damages. Earthquake occurrence mechanism is important to assess the geohazard potentials. Continental‐scale Quaternary fault system is developed across the Seoul metropolitan area where the population is the largest in the Korean Peninsula. Historical seismic‐damage records suggest potential seismic hazards in the Seoul metropolitan area. We investigate the fault motions and spatial distribution of earthquakes in the Seoul metropolitan area using a matched‐filter technique that is based on stacked waveform crosscorrelation functions among densely‐deployed seismic stations. The analysis detects 1103 earthquakes that include 360 events with magnitudes (ML) of −0.6 to 2.0 around the Chugaryeong fault and 34 events with magnitudes of −0.5 to 2.7 around Wangsukcheon, Pocheon, and Yeseonggang faults. The seismicity suggests a set of near‐vertical subparallel (or orthogonal) faults that develop from the major faults. A major fault system behaves as a backbone structure that makes branch faults develop, producing seismicity including major earthquakes. The backbone structure may control the fault development that conforms to the ambient stress field. The backbone faults may play a role to increase geohazard potentials.

In this article, meniscus-guided printing of polyelectrolyte-attached liquid metal particles to simultaneously achieve mechanical stability and initial electrical conductivity at high resolution is introduced.

Abstract Background Comparative genomic analysis exhibits dynamic evolution of plastid genome (plastome) in the clusioid clade of Malpighiales, which comprise five families, including multiple inversions and gene losses. Little is known about the plastome evolution in Hypericaceae, a large family in the clade. Only the plastome of one species, Cratoxylum cochinchinense, has been published. Results We generated a complete plastome sequence for Hypericum ascyron, providing the first complete plastome from the tribe Hypericeae (Hypericaceae). The H. ascyron plastome exhibits dynamic changes in gene and intron content, structure, and sequence divergence compared to the C. cochinchinense plastome from the tribe Cratoxyleae (Hypericaceae). Transcriptome data determined the evolutionary fate of the missing plastid genes infA, rps7, rps16, rpl23, and rpl32 in H. ascyron. Putative functional transfers of infA, rps7, and rpl32 were detected to the nucleus, whereas rps16 and rpl23 were substituted by nuclear-encoded homologs. The plastid rpl32 was integrated into the nuclear-encoded SODcp gene. Our findings suggested that the transferred rpl32 had undergone subfunctionalization by duplication rather than alternative splicing. The H. ascyron plastome rearrangements involved seven inversions, at least three inverted repeat (IR) boundary shifts, which generated gene relocations and duplications. Accelerated substitution rates of plastid genes were observed in the H. ascyron plastome compared with that of C. cochinchinense plastid genes. The higher substitution rates in the accD and clpP were correlated with structural change, including a large insertion of amino acids and losses of two introns, respectively. In addition, we found evidence of positive selection of the clpP, matK, and rps3 genes in the three branches related to H. ascyron. In particular, the matK gene was repeatedly under selection within the family Hypericaceae. Selective pressure in the H. ascyron matK gene was associated with the loss of trnK-UUU and relocation into the IR region. Conclusions The Hypericum ascyron plastome sequence provides valuable information for improving the understanding of plastome evolution among the clusioid of the Malpighiales. Evidence for intracellular gene transfer from the plastid to the nucleus was detected in the nuclear transcriptome, providing insight into the evolutionary fate of plastid genes in Hypericaceae.

Background Acupotomy is a type of acupuncture where a scalpel-shaped needle (miniscalpel needle) is used instead of a normal acupuncture needle to exfoliate adhesion sites or to relax entrapped regions. This study aimed to identify the descriptive characteristics of patients who received acupotomy treatment at a single Korean Medicine Clinic. Methods This retrospective review analyzed the medical charts of patients who had received acupotomy at least once from August 2017 to December 2019 at a single Korean Medicine Clinic. The demographic characteristics, chief complaints, acupotomy treatment sites, and principal diagnosis codes were analyzed. Results We identified 551 outpatients; the average age was 52 ± 14.26 years and 49.9% were male. The patients underwent an average of 8.47 sessions of acupotomy. Altogether, 35.91% of the acupotomy treatments were administered to the spinal regions, of which 60.01% were in the lumbar region. The codes related to the lumbar spinal condition/disease which were used most frequently. The chief complaints were dizziness, lumbar spinal stenosis, and Dupuytren’s contracture in patients over 60 years of age. Conclusions This is the 1st analysis of acupotomy treatment patterns in Korea to date. Acupotomy is primarily administered in the treatment of spinal conditions/diseases, especially for those involving the lumbar region. Future studies are necessary to determine the clinical outcomes of patients who receive acupotomy treatment and the safety of this treatment.

Fiber‐optic technology emerged originally for applications in data transmission and telecommunications. However, sensors based on fiber‐optics have been developed rapidly because of their excellent sensing performances and capability to function in remote and harsh environments. The usage of fiber‐optic sensors has flourished in many fields over the past 30 years due to the fiber‐optic's inherent advantages: cost‐effectiveness, miniaturized size, light weight, and immunity to electromagnetic interference. This work reviews the fiber‐optic sensors based on Bragg gratings, long period gratings, interferometers, surface plasmon resonance, fluorescence, and light diffusion. Brief theory of sensing principle, fabrication method, applications, advantages and disadvantages of the different fiber‐optic sensors, are addressed. Recent progress in numerous sensing fields, including environmental, industrial, and biomedical are discussed for each class of fiber‐optic sensors. The review highlights the methods and techniques used to overcome the sensing challenges. Finally, prospect of future developments of fiber‐optic sensors is summarized.

This study proposes an eco-friendly (ECO) mold that is fabricated using the laser powder bed fusion (LPBF) method, which utilizes a three-dimensional (3D) cooling channel. Unlike previous studies, we designed surface-type conformal cooling channels (CCC) based on the design concept for additive manufacturing, at a constant depth corresponding to the casting part. Pin fins were installed inside the surface-type cooling channels and aligned through numerical analysis to induce the turbulence of the coolant uniformly through the cooling channel while generating less thermal stress during solidification of the as-cast Al-Si alloy-based product, which increased the cooling efficiency of the proposed ECO mold. Moreover, the ECO mold was utilized to cast an automobile piston to demonstrate its feasibility at an industrial level. The results showed that, the casting process decreased significantly from 133 to 105 s per piston (21% reduction) compared to the conventional mold with a single columnar cooling channel. Additionally, the average grain size of the ECO mold decreased from 502 to 398 µm. The ultimate tensile strength and Rockwell hardness increased by 12.5% and 5.5%, respectively.

Abstract An approximately 40‐km long high‐resolution reflection seismic profile (P3) was acquired in the metropolitan area of Seoul in South Korea for the purpose of fault system imaging in a highly noisy and challenging urban environment. Two 12t seismic vibrators (mini‐vibs) were used as the seismic source. Data were recorded using a dual element seismic spread; 20 m spaced 421 wireless seismic recorders connected to 10 Hz geophones and 20 micro‐electro‐mechanical‐based landstreamer sensors (2 m sensor spacing) attached to one of the vibrators. The purpose of the dual spread employed was to delineate both near‐surface and deep structures. The processing results show good quality and the processing work was complemented by different analysis to further constraints the geological interpretation. The survey results provide evidence for the 3D geometry of three fault systems, including Chugaryeong, Pocheon, and Wangsukcheon faults. A gently westerly dipping set of reflectivity underlying a dome‐shaped package of reflectivity is interpreted as a fault, and could project to the known surface position of the Pocheon fault. The dome‐shaped reflectivity is interpreted as folded and faulted dyke or sill systems. Downward continuation of the interpreted fault intersects the sub‐vertical Chugaryeong fault in a zone where the current seismicity is observed, suggesting that these two major fault systems may have jointly evolved in the form of splay faults. Reflections from the Wangsukcheon fault are also present in the data and interpreted to dip approximately 60° to the east, in an opposite direction to the two other faults.

Neural probes for experimental studies can cause tissue damage. Here the authors describe a probe incorporated with a hydrogel structure for adaptive bending stiffness to enable insertion to the rodent brain while minimising tissue damage.

This review comprehensively reviewed floating offshore wind power generation technology, which is being newly developed as a mid- to long-term plan for wind energy. From the perspective of investment permegawatt (MW), offshore wind power is still about 50 percent more expensive than land wind power. Nevertheless, many advanced countries began to investigate the data because they wondered why they were immersed in development and investment, and why offshore wind facilities installed on the beach and floating offshore wind installed in the middle of the sea, unlike the land wind we knew. We looked at the basic principles of offshore wind power generation and the technologies used in facilities, and looked at the advantages and disadvantages of offshore wind power generation compared to land wind power generation, and what differences between fixed offshore wind farms and floating offshore wind farms. It is investigated whether it is a realistic plan to verify residents’ opposition to the installation of offshore wind power facilities, the possibility of commercialization such as high operational management costs, and the feasibility of installing facilities for renewable energy 3020 as midto long-term goals. In addition, it compares foreign cases with offshore wind power development complexes in Korea, marine wind power generation complexes in operation, and high wind power in Scotland, the first floating offshore wind power in Ulsan, Korea, to overcome difficulties in installing facilities and suggest directions for domestic offshore wind power development. In addition, in Korea, where there are not many countries suitable for wind power generation unlike overseas, it was decided to investigate whether floating offshore wind power could be the answer as planned. The reason why the government is pushing for investment in renewable energy such as solar power and wind power is because energy sources from the sun are eco-friendly. However, the U.S. and Europe, which started the wind power project early, are having difficulty in handling the wings of wind power generators. The energy source looked at the contradictions caused by environmental pollution in the treatment of waste, although it was environmentally friendly, and investigated how waste was treated and utilized overseas. Compared to other countries that entered the offshore wind power business earlier, domestic power generation projects are in their infancy and should focus on developing technology and co-prosperity with neighboring residents rather than on excessive expansion.

Summary: Along with the advancement in neural engineering techniques, unprecedented progress in the development of neural interfaces has been made over the past few decades. However, despite these achievements, there is still room for further improvements especially toward the possibility of monitoring and modulating neural activities with high resolution and specificity in our daily lives. In an effort of taking a step toward the next-generation neural interfaces, we want to highlight the recent progress in neural technologies. We will cover a wide scope of such developments ranging from novel platforms for highly specific recording and modulation to system integration for practical applications of novel interfaces.

Abstract We investigate the upper‐crustal seismic velocity structure in the Seoul metropolitan area, where about 20 million people live. The Chugaryeong fault zone (CFZ) is placed in this area, but the seismic hazard potential remains unclear. We conducted ambient noise tomography to illuminate the high‐resolution upper‐crustal structure in the Seoul metropolitan area. We analyzed continuous vertical seismic records for ∼5 months from a dense seismic array with 77 broadband stations. Group velocity dispersion curves and tomographic maps were extracted between 0.5 and 10 s periods. We inverted 3‐D group velocity tomography models up to a depth of ∼10 km from the group velocity maps. The shear‐wave velocity model is consistent with the geological features. High‐velocity anomalies at shallow depths are correlated with the surface topography and geology. The CFZ is located at a low velocity below the 5 km depth and presented as the simplified model. The large VS contrast regions are located beneath NS‐trending faults. The cross‐sections coincide with the near‐vertical strike‐slip faults in this area. In the southern region of the Seoul metropolitan area, low‐velocity anomalies correlate with high heat flow regions. Our results effectively suggest high resolution upper‐crustal structures and subsurface hidden faults in the urban area.

Background: Abdominal organ injuries are a rarely reported complication when deep acupuncture needling is applied to the abdomen. In order to ascertain the allowable needle insertion range (ANIR) of the abdomen region, we selected acupoint CV12, which is commonly used for treating gastric disease, and ANIR was measured with an ultrasound device. Method: Eighty-five healthy volunteers were recruited, of which 83 cases of ultrasound images were obtained. To investigate the prediction factor of ANIR, we also measured several anthropometric factors. Results: The average ANIR was 25.3 ± 10.2; generally, the ANIRs of females were thicker than those of males; and the liver was observed in 62.7% subjects’ ultrasound images. The non-observed group showed thicker ANIR and higher BMI than the liver-observed group. Conclusion: There are reliable variables that make it possible to predict the ANIR. It is advised to refer to anthropometric factors in needling acupoint CV12 to avoid complications with the acupuncture treatment. However, individual differences are not negligible when applying deep needling. Thus, if the risk is not judged before or during the procedure, practitioners could consider the patient’s ANIR on CV12 when applying acupuncture by examining the individual anatomical structures using ultrasound and considering internal organ positions to prevent adverse events due to acupuncture.

Functional gene transfer from organelles to the nucleus, known as intracellular gene transfer (IGT), is an ongoing process in flowering plants. The complete plastid genomes (plastomes) of two Ulleung island endemic violets, Viola ulleungdoensis and V. woosanensis, were characterized, revealing a lack of the plastid-encoded infA, rpl32, and rps16 genes. In addition, functional replacement of the three plastid-encoded genes in the nucleus was confirmed within the genus Viola and the order Malpighiales. Three strategies for the acquisition of a novel transit peptide for successful IGT were identified in the genus Viola. Nuclear INFA acquired a novel transit peptide with very low identity between these proteins, whereas the nuclear RPL32 gene acquired an existing transit peptide via fusion with the nuclear-encoded plastid-targeted SOD gene (Cu-Zn superoxide dismutase superfamily) as one exon, and translated both proteins in the cytosol using alternative mRNA splicing. Nuclear RPS16 contains an internal transit peptide without an N-terminal extension. Gene loss or pseudogenization of the plastid-borne rpl32 and rps16 loci was inferred to occur in the common ancestor of the genus Viola based on an infrageneric phylogenetic framework in Korea. Although infA was lost in the common ancestor of the order Malpighiales, the rpl32 and rps16 genes were lost multiple times independently within the order. Our current study sheds additional light on plastid genome composition and IGT mechanisms in the violet genus and in the order Malpighiales.

Abstract Quaternary faults run across the Seoul metropolitan area that is the highest population region in the Korean Peninsula. Active fault identification and seismic hazard potential assessment are crucial for public safety. Densely deployed permanent and temporal seismic stations enabled us to detect micro to small earthquakes, allowing us to identify earthquake‐spawning faults in Seoul metropolitan area. The source parameters of 455 earthquakes in 2004–2020 are refined. The Gutenberg‐Richter b value is 0.94. Dominant focal depths are 4–15 km. The focal mechanism solutions of 64 earthquakes are determined using seismic‐wave polarities and amplitude ratios. Strike‐slip earthquakes are dominant in the region. Earthquakes are clustered around the Chugaryeong fault system. The dominant strikes of fault planes range from N20°E to N45°E in the northern and southern Seoul metropolitan areas, suggesting branch fault development locally. The earthquakes in middle‐northern Seoul present N‐S directional strike‐slip motions at depths ∼7.5 km along the Chugaryeong fault, suggesting seismically active near‐vertical faults subparallel with Chugaryeong fault.

Abstract DNA transfer between internal organelles such as the nucleus, mitochondrion, and plastid is a well-known phenomenon in plant evolution, and DNA transfer from the plastid and mitochondrion to the nucleus, from the plastid to the mitochondrion, and from the nucleus to the mitochondrion has been well-documented in angiosperms. However, evidence of the transfer of mitochondrial DNA (mtDNA) to the plastid has only been found in three dicotyledons and one monocotyledon. In the present study, we characterised and analysed two chloroplast (cp) genome sequences of Convallaria keiskei and Liriope spicata, and found that C. keiskei has the largest cp genome (162,109 bp) in the Asparagaceae. Interestingly, C. keiskei had a ~3.3-kb segment of mtDNA in its cp genome and showed similarity with the mt gene rpl10 as a pseudogene. Further analyses revealed that mtDNA transfer only occurred in C. keiskei in the Nolinoideae, which diverged very recently (7.68 million years ago (mya); 95% highest posterior density (HPD): 14.55–2.97 mya). These findings indicate that the C. keiskei cp genome is unique amongst monocotyledon land plants, but further work is necessary to understand the direction and mechanism involved in the uptake of mtDNA by the plastid genome of C. keiskei.

Abstract Background Lychnis kiusiana Makino is an endangered perennial herb native to wetland areas in Korea and Japan. Despite its conservational and evolutionary significance, population genetic resources are lacking for this species. Next-generation sequencing has been accepted as a rapid and cost-effective solution for the identification of microsatellite markers in nonmodel plants. Results Using Illumina HiSeq 2000 sequencing technology, we assembled 67,498,600 reads into 91,900 contigs and identified 11,403 microsatellite repeat motifs in 9563 contigs. A total of 4510 microsatellite-containing transcripts had Gene Ontology (GO) annotations, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified 124 pathways with significant scores. Many microsatellites in the L. kiusiana leaf transcriptome were linked to genes involved in the plant response to light intensity, salt stress, temperature stimulus, and nutrient and water deprivation. A total of 12,486 single-nucleotide polymorphisms (SNPs) were identified on transcripts harboring microsatellites. The analysis of nucleotide substitution rates for 2389 unigenes indicated that 39 genes were under strong positive selection. The primers of 6911 microsatellites were designed, and 40 of 50 selected primer pairs were consistently and successfully amplified from 51 individuals. Twenty-five of these were polymorphic, and the average number of alleles per SSR locus was 6.96, with a range from 2 to 15. The observed and expected heterozygosities ranged from 0.137 to 0.902 and 0.131 to 0.827, respectively, and locus-specific F IS estimates ranged from − 0.116 to 0.290. Eleven of the 25 primer pairs were successfully amplified in three additional species of Lychnis: 56% in L. wilfordii, 64% in L. cognata and 80% in L. fulgens. Conclusions The transcriptomic SSR markers of Lychnis kiusiana provide a valuable resource for understanding the population genetics, evolutionary history, and effective conservation management of this species. Furthermore, the identified microsatellite loci linked to the annotated genes should be useful for developing functional markers of L. kiusiana. The developed markers represent a potentially valuable source of transcriptomic SSR markers for population genetic analyses with moderate levels of cross-taxon portability.

Background: Since January 2020, novel coronavirus (SARS-Cov-2) – infected pneumonia (COVID-19) rapidly spread in Korea. This study aimed to introduce the Korean Medicine (KM) telemedicine center for treatment of COVID patients in Korea. Methods: This work was a retrospective review of medical records on patients who received at least one telemedicine session from March 9, 2020 to April 12, 2020 provided by the COVID-19 telemedicine center of Korean Medicine. Data on demographic characteristics, treatment frequency, number of consultation were collected. A descriptive statistical analysis was conducted to report characteristics of patients. Results: A total of 1742 patients underwent consultation through KM telemedicine centers. Despite the rapid increase in the number of patients, the telemedicine center provided treatments to an average of 192 patients per day by about an average of 15 doctors. Furthermore, 4552 herbal medicines were prescribed through telemedicine center, among which 1366 cases (30%) being Qing-Fei-Pai-Du-tang. Telemedicine care also has shown that even with patient's residence transition, medical care can be continued without pause. Conclusion: These results show some advantages of the telemedicine center's implementation in terms of the effective use of medical resources and continuous treatment for patients.

For construction sites within cities, which require fast construction because of restrictions in road occupation time, or for other occasions where construction period is an important factor because of similar reasons, application of a modular construction method using precast members is efficient in terms of shortening the construction period. The substructures of bridges are normally constructed using cast-in-place, which has been a major cause of delays in construction. Application of a modular construction method could decrease the occupation time in the sites. A prime example is the Accelerated Bridge Construction (ABC) by the Texas Department of Transportation (TDOT) and Federal Highway Administration (FHWA). Precast members are the key components of ABC. The main purpose of this paper is to provide clear seismic performance standards for precast bridge piers. Current seismic design codes require force-based design checks and provide qualitative evaluation of the overall structure. They do not provide specific qualitative criteria for individual structures with particular types. Previous research has been focused on reinforced-concrete bridge piers, while lacking on research towards prefabricated bridge piers with continuous reinforcements. In order to quantitatively evaluate the seismic performance level of prefabricated bridge piers, the seismic performance was quantitatively suggested in accordance with the classification of four which are operational, immediate occupancy, life safety, and collapse prevention. These criteria are cracking of cover concrete, crushing of cover concrete, yielding of axial steels, and fracture of axial steels. Based on the given seismic performance evaluation criteria, evaluation and verification were conducted on four prefabricated bridge piers with continuous reinforcement that have undergone quasistatic cyclic experiments. The moment-curvature analysis model was constructed for the parametric study and verified through experimental results. Based on the developed M-Phi model, prefabricated bridge piers with continuous reinforcement, which were designed force-based using response correction factor, were evaluated. In addition, parametric study was also conducted focusing on concrete strength, magnitude of prestress, and transverse reinforcement. Depending on the level of individual performance produced by ranges of these variables within possible runs on actual piers, the impact of 3 variables was analyzed. Furthermore, in response to changes in each variable, the impact on the relevant seismic performance level was verified through response spectrum analysis.

Caprifoliaceae s.l. plastid genomes (plastomes) show that one inversion and two inverted repeat boundary shifts occurred in the common ancestor of this family, after which the plastomes are generally conserved. This study reports plastome sequences of five additional species, Fedia cornucopiae, Valeriana fauriei, and Valerianella locusta from the subfamily Valerianoideae, as well as Dipsacus japonicus and Scabiosa comosa from the subfamily Dipsacoideae. Combined with the published plastomes, these plastomes provide new insights into the structural evolution of plastomes within the family. Moreover, the three plastomes from the subfamily Valerianoideae exhibited accelerated nucleotide substitution rates, particularly at synonymous sites, across the family. The patterns of accD sequence divergence in the family are dynamic with structural changes, including interruption of the conserved domain and increases in nonsynonymous substitution rates. In particular, the Valeriana accD gene harbors a large insertion of amino acid repeat (AAR) motifs, and intraspecific polymorphism with a variable number of AARs in the Valeriana accD gene was detected. We found a correlation between intron losses and increased ratios of nonsynonymous to synonymous substitution rates in the clpP gene with intensified positive selection. In addition, two Dipsacoideae plastomes revealed the loss of the plastid-encoded rps15, and a potential functional gene transfer to the nucleus was confirmed.

The development of a compliant neural probe is necessary to achieve chronic implantation with minimal signal loss. Although fiber-based neural probes fabricated by the thermal drawing process have been proposed as a solution, their long-term effect on the brain has not been thoroughly investigated. Here, we examined the mechanical interaction of thermally drawn fiber implants with neural tissue through computational and histological analyses. Specifically, finite element analysis and immunohistochemistry were conducted to evaluate the biocompatibility of various fiber implants made with different base materials (steel, silica, polycarbonate, and hydrogel). Moreover, the effects of the coefficient of friction and geometric factors including aspect ratio and the shape of the cross-section on the strain were investigated with the finite element model. As a result, we observed that the fiber implants fabricated with extremely softer material such as hydrogel exhibited significantly lower strain distribution and elicited a reduced immune response. In addition, the implants with higher coefficient of friction (COF) and/or circular cross-sections showed a lower strain distribution and smaller critical volume. This work suggests the materials and design factors that need to be carefully considered to develop future fiber-based neural probes to minimize mechanical invasiveness.

Wearable electronics have been receiving increasing attention for the past few decades. Particularly, fiber-based electronics are considered to be ideal for many applications for their flexibility, lightweight, breathability, and comfortability. Furthermore, fibers and fiber-based textiles can be 3D-molded with ease and potentially integrated with everyday clothes or accessories. These properties are especially desired in the fields of bio-related sensors and energy-storage systems. Wearable sensors utilize a tight interface with human skin and clothes for continuous environmental scanning and non-invasive health monitoring. At the same time, their flexible and lightweight properties allow more convenient and user-friendly experiences to the wearers. Similarly, for the wearable devices to be more accessible, it is crucial to incorporate energy harvesting and storage systems into the device themselves, removing the need to attach an external power source. This review summarizes the recent applications of fibers and fiber-based textiles in mechanical, photonic, and biomedical sensors. Pressure and strain sensors and their implementation as electronic skins will be explored, along with other various fiber sensors capable of imaging objects or monitoring safety and health markers. In addition, we attempt to elucidate recent studies in energy-storing fibers and their implication in self-powered and fully wireless wearable devices.

Traditional non-volatile memories suffer from poor scalability in the vertical direction due to the use of a bulky oxide layer. Here, the authors develop a tunnelling random access memory using a vertical heterostructure composed of atomically thin molybdenum disulfide, boron nitride and graphene.

Additive interface materials for improved ionic polymer metal composite (IPMC) actuator performance are being investigated. In this study, three-dimensional carbon nanostructure/copper nanowire (3DC Cu-NW) with a novel structure was synthesized via low-pressure chemical vapor deposition. An IPMC actuator with a 3DC Cu-NW interface layer was fabricated, which exhibited improved actuation performance, long-term stability, and electrochemical properties. The proposed 3DC consists of carbon nanotubes (CNTs) and graphene, grown using an Fe catalyst and CH4 gas, respectively. We optimized the growth conditions (Fe catalyst: 12.5 mg/L, CH4: 20 sccm) to achieve a 3DC with an appropriate thickness and a large specific surface area. The 3DC Cu-NW benefited from a Cu oxidation prevention property and a large specific surface area. The electrochemical properties and actuation performance of the IPMC actuator improved with an increased 3DC Cu-NW concentration. An IPMC actuator with a 0.6 wt% 3DC Cu-NW interface layer exhibited 1.3- and 5.6-fold electrochemical property and actuation performance improvement, respectively, over an IPMC actuator with no 3DC Cu-NW interface layer. These results show that the proposed 3DC Cu-NW has potential as an IPMC actuator interface material, and that 3DC Cu-NW synthesis and application technology can be applied to future research on sensor, actuator, and flexible devices.

Since 1992, porcine epidemic diarrhea virus (PEDV) has been one of the most common porcine diarrhea–associated viruses in South Korea. We conducted a large-scale investigation of the incidence of PEDV in pigs with diarrhea in South Korea and consequently identified and characterized a novel PEDV variant with a large genomic deletion.

Although triboelectric nanogenerator (TENG) has been explored as one of the possible candidates for the auxiliary power source of portable and wearable devices, the output energy of a TENG is still insufficient to charge the devices with daily motion. Moreover, the fundamental aspects of the maximum possible energy of a TENG related with human motion are not understood systematically. Here, we confirmed the possibility of charging commercialized portable and wearable devices such as smart phones and smart watches by utilizing the mechanical energy generated by human motion. We confirmed by theoretical extraction that the maximum possible energy is related with specific form factors of a TENG. Furthermore, we experimentally demonstrated the effect of human motion in an aspect of the kinetic energy and impulse using varying velocity and elasticity, and clarified how to improve the maximum possible energy of a TENG. This study gives insight into design of a TENG to obtain a large amount of energy in a limited space.

Cu nanowires (NWs) possess remarkable potential a slow-cost heat transfer material in modern electronic devices. However, Cu NWs with high aspect ratios undergo surface oxidation, resulting in performance degradation. A growth temperature of approximately

This study proposes a collaboration-based interaction as a new method for providing an improved presence and a satisfying experience to various head-mounted display (HMD) users utilized in immersive virtual reality (IVR), and analyzes the experiences (improved presence, satisfying enjoyment, and social interaction) of applying collaboration to user interfaces. The key objective of the proposed interaction is to provide an environment where HMD users are able to collaborate with each other, based on their differentiated roles and behaviors. To this end, a collaboration-based interaction structured in three parts was designed, including a synchronization procedure and a communication interface that enable users to swiftly execute common goals with precision, based on immersive interactions that allow users to directly exchange information and provide feedback with their hands and feet. Moreover, experimental VR applications were built to systematically analyze the improved presence, enjoyment, and social interaction experienced by users through collaboration. Finally, by conducting a survey on the participants of the experiment, this study confirmed that the proposed interface indeed provided users with an improved presence and a satisfying experience, based on collaboration.

In South Korea, where avian influenza virus subtypes H3N2, H5N1, H6N1, and H9N2 circulate or have been detected, 3 genetically similar canine influenza virus (H3N2) strains of avian origin (A/canine/Korea/01/2007, A/canine/Korea/02/2007, and A/canine/Korea/03/2007) were isolated from dogs exhibiting severe respiratory disease. To determine whether the novel canine influenza virus of avian origin was transmitted among dogs, we experimentally infected beagles with this influenza virus (H3N2) isolate. The beagles shed virus through nasal excretion, seroconverted, and became ill with severe necrotizing tracheobronchitis and bronchioalveolitis with accompanying clinical signs (e.g., high fever). Consistent with histologic observation of lung lesions, large amounts of avian influenza virus binding receptor (SAα 2,3-gal) were identified in canine tracheal, bronchial, and bronchiolar epithelial cells, which suggests potential for direct transmission of avian influenza virus (H3N2) from poultry to dogs. Our data provide evidence that dogs may play a role in interspecies transmission and spread of influenza virus.

A series of moderate-size (MW 4.0-6.0) earthquakes occurred in South Korea after the 2011 MW 9.0 Tohoku-Oki megathrust earthquake, incurring public concern about possible occurrence of devastating earthquakes in Seoul--the capital city of South Korea, where historical seismic damage was reported. The seismicity is distributed in Seoul, being dominated by strike-slip earthquakes. The fault planes are oriented in north-northeast-south-southwest, which is a favorable direction to respond to the ambient stress field. Higher rates of seismicity are observed in the northwestern Seoul at depths of <10 km. Micro-to-small earthquakes occur episodically in the central Seoul along the Chugaryeong fault system that traverses Seoul in north-south. Seismic, geophysical, and geological properties illuminate the fault structures. Stochastic modeling of ground motions reproduces the seismic damages of historical earthquakes reasonably, supporting the occurrence of devastating historical earthquakes in Seoul. The seismicity distribution, focal mechanism solutions, geological features, and seismic and geophysical properties suggest the possible presence of earthquake-spawning blind faults in Seoul. The peak ground motions are assessed for moderate-size scenario earthquakes (MW 5.4 with focal depth of 7 km) at six representative subregions in Seoul. The upper bounds of peak ground accelerations reach 11 m/s². The seismic damage potentials for moderate-size earthquakes are high in most areas of Seoul, particularly around river sides covered by alluvium. [ABSTRACT FROM AUTHOR]

Correct sensor orientation is vital for seismological analysis. However, seismic sensors including both borehole and surface seismometers are often installed in incorrect orientations. Individual methods proposed for sensor-orientation determination suffer from their own limitations and uncertainty, leaving the estimates in question before on-site verification. We introduce a method to combine a set of seismic phase analyses, yielding accurate sensor-orientation estimates. The method determines the sensor orientations by weighted-averaging independent estimates from three individual sensor-orientation analyses that are based on earthquake-origin P waves, earthquake-origin Rayleigh waves, and microseism-origin Rayleigh waves. The earthquake-origin seismic phase analyses may suffer from seismic anisotropy along ray paths even with accurate source-location information. On the other hand, the microseism-origin Rayleigh-wave analysis is hardly affected by seismic anisotropy along ray paths, being applicable to any seismic station with a couple of hour-long records. The three analyses complement each other, which enables us to determine representative sensor orientations correctly. We apply the proposed method to densely deployed 377 seismometers in South Korea, examining the sensor orientations. The representative sensor orientations are determined stably with standard errors less than 1°, supporting the accuracy of results. Borehole seismometers are poorly oriented relative to surface seismometers. The proposed method is useful for instant examination of sensor orientations of seismometers in remote regions and borehole seismometers in which physical accessibility is highly limited. [ABSTRACT FROM AUTHOR]