Ultra-low Rates Research Articles

The adoption of corporate family-friendly policies in South Korea from the 1960s to 2023: a three-stage model for emerging economies

Purpose This paper aims to present the trajectory of corporate family-friendly policies (FFPs) in South Korea, as it evolved from an emerging economy to a developed country. The adoption of FFPs by South Korean corporations since the 1960s has been shaped by a dynamic interplay of cultural, political, economic, legal, social and organizational forces. The authors use the example of South Korea to propose a three-stage conceptual model for the adoption of FFPs in emerging economies. Design/methodology/approach Adopting the institution-based view, the authors explore the theoretical framework for implementing FFPs in corporations in emerging economies. This paper uses South Korea as a case study, reviewing its economic and corporate transitions from the early 1960s through 2023. The authors analyze cultural and macro-level forces, including political, economic, legal and social contexts to understand their impact on the adoption of FFPs. Findings The adoption of FFPs in South Korea encompassed three historical stages – embryonic, stagnant and leaping. The embryonic stage brought the birth of social interest in a worker-friendly environment, alongside rapid economic growth. In the stagnant stage, economic growth plateaued, resulting in stalled discussions of FFPs. In the leaping stage, economic recovery raised employee expectations, societal demands for FFPs to address ultralow fertility rates intensified and corporations adopted FFPs. All three stages are apparent in an emerging economy that is undergoing rapid growth and industrialization. Originality/value There has been scant investigation into the historical adoption of FFPs by emerging economies. The findings enrich the international literature by proposing a developmental model of the adoption of FFPs in emerging economies.

Phase Demodulation under Ultra-low sampling rate in heterodyne coherent [formula omitted]-OTDR

Heterodyne coherent phase-sensitive optical time-domain reflectometry(Φ-OTDR) requires a higher data sampling rate to demodulate phase in the “distance” direction effectively. Aiming at the problem of large amount of demodulated data, we propose a phase demodulation method that can effectively recover disturbance information from ultra-low sampling data. This method demodulates the phase of the two-dimensional reconstructed signal in the “time” direction. Thus, the influence of spectrum aliasing in the “distance” direction caused by undersampling is avoided. The undersampling rate is not limited by the spectrum aliasing effect of the detected signal when using this method to demodulate phase. Therefore, accurate phase information can be retrieved under ultra-low sampling rates, significantly reducing the data for phase demodulation in heterodyne coherent Φ-OTDR. In the experiment, three sampling rates (100 MSa/s, 10 MSa/s, 1 MSa/s) within the restricted area of the traditional undersampling demodulation method were selected to acquire data, and the proposed method can also accurately demodulate phase information.

Map matching on low sampling rate trajectories through deep inverse reinforcement learning and multi-intention modeling

Analyzing freight vehicle movements using GPS trajectory data presents challenges due to environmental conditions and hardware limitations impacting data accuracy. Map matching, the process of aligning GPS signals with road networks, facilitates accurate route reconstruction. However, existing methods have limitations, particularly with low and ultra-low sampling rates. They often assume the shortest path between points, overlook historical data insights and neglect diverse driving behaviors, which may not align with real-world scenarios where shortest paths are not always optimal and different drivers exhibit varied behaviors. These limitations affect existing methods’ reliability, especially when we face low sampling rate trajectories. In this study, we propose multi-intention deep inverse reinforcement learning for map matching (MIDIRL) to address these challenges. MIDIRL integrates deep neural networks and multi-intention capturing mechanisms with inverse reinforcement learning to model complex driving preferences from historical trajectories, improving map matching accuracy, especially in ultra-low-frequency trajectories. Our experiments on real-world datasets demonstrate MIDIRL’s improved accuracy and efficiency of map matching compared to previous methods, even with limited training data.

Spatial clusters for demand and supply of early childhood education and care services in Italy

In recent years, concern has increased about affordable and high-quality early childhood education and care (ECEC) services. Such services can help balance work and family life, increase workforce participation, promote gender equality, and increase fertility rates. ECEC services are then essential, especially for countries facing ultralow fertility rates like Italy. To face these challenges, the Italian government has included an unprecedented investment in the recovery and resilience plan financed with Next Generations EU funds to increase the supply of ECEC services and make them more equitably distributed across the country. However, socio-economic policies need a comprehensive understanding of demand dynamics and the intricate interplay between supply and demand of such services. Therefore, in this article, we propose a novel analysis of the complex combination of supply and demand of Italian ECEC services. We explore patterns of this combination in terms of groups of spatial areas sharing similar structures of service coverage and public expenditure rates in ECEC, as well as other socio-demographic and economic factors such as female employment, education, and grandparent rates. Our empirical findings confirm how Italy is characterized by several distinct territorial models and how some are shared across multiple regions. Current empirical findings suggest a lack of uniform governance across the Italian territory. Policymakers can use these results to plan, discuss, and implement area-specific welfare strategies regarding ECEC services.

Evaluate the Correlation Between Identified Social Issues and Ultra-low Fertility Rates in Hong Kong

Hong Kong has witnessed a significant and continuous decline in its total fertility rate (TFR) over the past few decades, hitting an ultra-low level. This article investigates various social issues that would probably contribute to this decline as previous studies suggest, including the women’s role incongruence, the extremely heavy financial burden, and the limited scope of government policies in Hong Kong society. The persistence of such low TFR in societies would deteriorate aging problems, increase the old-age dependency ratio, and shrink the labor force. These issues are thereby posing significant challenges to Hong Kong’s economic and political sustainability. Hence, it is necessary for policymakers to introduce effective policies to improve TFR by figuring out where the problem derives. To comprehensively comprehend the correlation between ultra-low TFR and identified social issues, this research employs two statistical models which are multiple linear regression and decision tree analysis. The results reveal a strong correlation between low TFR and some identified social problems, while also elucidating the coefficient of each factor. Simultaneously, the findings contradict some previous hypotheses claimed by scholars.

Time-resolved measurements of the ultra-low dissolution rates of two-dimensional arrays of platinum nanoparticles

Methods for the quantitative evaluation of platinum (Pt) dissolution are required to allow catalyst lifetimes in polymer electrolyte fuel cells (PEFCs) to be predicted. However, it is challenging to detect very slow Pt dissolution rates occurring at low potential fluctuations, such as during load cycles, as may occur in automotive fuel cells. The dissolution behavior of Pt nanoparticles (NPs) is also greatly affected by the catalyst layer thickness, particle size and inter-particle distance, and it is difficult to assess these effects separately. To address these problems, the present work prepared two-dimensionally distributed Pt NPs using coaxial arc plasma deposition. An online ICP-MS system was subsequently used to evaluate the dissolution rate of these NPs. The results showed that Pt dissolved primarily during cathodic scans in association with potential cycling with a high upper potential limit, such as would occur in a PEFC start-stop cycle. This dissolution was accompanied by the formation of Pt oxide. There was little difference in dissolution behavior between Pt NPs and bulk Pt. An extremely slow time-resolved dissolution rate was successfully measured in the low potential region below 1.0 V vs. a standard hydrogen electrode, indicating that anodic dissolution was the predominant Pt dissolution mechanism. In this case, a clear difference in dissolution behavior between the NPs and bulk metal was observed. The onset potential for NPs dissolution was lower than that for bulk Pt and smaller NPs dissolved faster than larger ones.

High-flux source system for matter-wave interferometry exploiting tunable interactions

Atom interferometers allow determining inertial effects to high accuracy. Quantum-projection noise as well as systematic effects impose demands on large atomic flux as well as ultralow expansion rates. Here we report on a high-flux source of ultracold atoms with free expansion rates near the Heisenberg limit directly upon release from the trap. Our results are achieved in a time-averaged optical dipole trap and enabled through dynamic tuning of the atomic scattering length across two orders of magnitude interaction strength via magnetic Feshbach resonances. We demonstrate Bose-Einstein condensates with more than 6×104 particles after evaporative cooling for 170 ms and their subsequent release with a minimal expansion energy of 4.5 nK in one direction. Based on our results we estimate the performance of an atom interferometer and compare our source system to a high performance chip trap, as readily available for ultraprecise measurements in microgravity environments. Published by the American Physical Society 2024

Optimizing the ordering of the Hadamard masks of ghost imaging suitable for the efficient face reconstruction using the max-projection method

One crucial component of ghost imaging (GI) is the encoded mask. Higher-quality reconstruction at lower sampling rates is still a major challenge for GI. Inspired by deep learning, max-projection method is proposed in the paper to reorder the Hadamard masks for its efficient and rapid reconstruction. The simulations demonstrated that max-projection ordering with only 20 face training images yielded excellent reconstruction outcomes. In noise-free simulations, at an ultralow sampling rate of 5%, the PSNR of the max-projection ordering was 1.1 dB higher than that of the cake-cutting ordering with the best performance in the reference group. In noisy simulations, at ultralow sampling rates, the retrieved images remained almost identical to their noise-free counterparts. Irrespective of the presence or absence of noise, the max-projection ordering guaranteed the highest fidelity of image reconstruction at ultralow sampling rates. The reconstruction time was reduced to mere milliseconds, thereby enabling swift visualization of dynamic phenomena. Accordingly, the max-projection ordering Hadamard matrix offers a promising solution for real-time GI due to its higher reconstruction quality, stronger noise immunity and millisecond reconstruction time.

Nexus between inflation and inflation expectations at the zero lower bound: A tiger by the tail

Ultra-low policy rates and zero lower bounds (ZLB) have been major issues for monetary policy formulation. In this context, we investigate the nexus between inflation and inflation expectations. Employing a non-linear ADRL framework on UK and Canadian datasets, we find significant asymmetries in the nexus among inflation and inflation expectations and their determinants, including labour market slack, output gap, oil shocks, fiscal deficit and exchange rates. Heterogeneities are explicit in the short and long-term as well as in the pre-and post-ZLB regimes. Inflation and inflation expectations become more responsive to their determinants as key policy rates approach the ZLB. There is strong evidence of persistence in inflation and inflation expectations in both regimes manifesting the importance of keeping expectations well anchored. Robustness testing with Time-Varying Parameter Vector Auto-Regression and Network Analysis confirms our findings. To mitigate the persistence of a high inflation regime, it would be vital to keep the inflation expectations well anchored.

Image denoising and deringing for fourier single-pixel imaging based on upgraded weighted nuclear norm minimization

Single-pixel imaging techniques have been extensively studied because of the low requirements for the detector resolution and the low equipment cost. However, a large amount of noise and ringing commonly occur in the reconstructed images via previous single-pixel imaging methods at ultra-low sampling rates, which limits the real applications. In this paper, a novel Fourier single-pixel imaging method is proposed to reconstruct high-quality single-pixel imaging images at ultra-low sampling rates, which involves the stages of Fourier single-pixel imaging, block matching, upgraded weight nuclear norm minimization, and aggregation. To decrease the computational burden while important image details, block matching and aggregation are employed for the blocks divided from the low-quality image reconstructed by Fourier single-pixel imaging. To adapt the proposed upgraded weight nuclear norm minimization to different contaminated images, an adaptive scheme for the iterative regularization parameter is proposed to update the traditional weight nuclear norm minimization. Experimental results indicate that the proposed Fourier single-pixel imaging method based on upgraded weight nuclear norm minimization exhibits the capacity to reliably and effectively reconstruct high-quality images for single-pixel imaging at low sampling rates, even at the sampling rate of 1 %. Experimental results also demonstrate that the proposed method performs better image reconstruction than some existing single-pixel imaging.

Video-rate Raman-based metabolic imaging by Airy light-sheet illumination and photon-sparse detection

Despite its massive potential, Raman imaging represents just a modest fraction of all research and clinical microscopy to date. This is due to the ultralow Raman scattering cross-sections of most biomolecules that impose low-light or photon-sparse conditions. Bioimaging under such conditions is suboptimal, as it either results in ultralow frame rates or requires increased levels of irradiance. Here, we overcome this tradeoff by introducing Raman imaging that operates at both video rates and 1,000-fold lower irradiance than state-of-the-art methods. To accomplish this, we deployed a judicially designed Airy light-sheet microscope to efficiently image large specimen regions. Further, we implemented subphoton per pixel image acquisition and reconstruction to confront issues arising from photon sparsity at just millisecondintegrations. We demonstrate the versatility of our approach by imaging a variety of samples, including the three-dimensional (3D) metabolic activity of single microbial cells and the underlying cell-to-cell variability. To image such small-scale targets, we again harnessed photon sparsity to increase magnification without a field-of-view penalty, thus, overcoming another key limitation in modern light-sheet microscopy.

Video-rate high-resolution single-pixel nonscanning photoacoustic microscopy.

Optical-resolution photoacoustic microscopy (OR-PAM) is widely utilized in biomedical applications because of its ability to noninvasively image biological tissues in vivo while providing high-resolution morphological and functional information. However, one drawback of conventional OR-PAM is its imaging speed, which is restricted by the scanning technique employed. To achieve a higher imaging frame rate, we present video-rate high-resolution single-pixel nonscanning photoacoustic microscopy (SPN-PAM), which utilizes Fourier orthogonal basis structured planar illumination to overcome the above-mentioned limitations. A 473 × 473 µm2 imaging field of view (FOV) with 3.73 µm lateral resolution and video-rate imaging of 30 Hz were achieved. In addition, in both in vitro cell and in vivo mouse vascular hemodynamic imaging experiments, high-quality images were obtained at ultralow sampling rates. Thus, the proposed high-resolution SPN-PAM with video-rate imaging speed provides new insights into high-speed PA imaging and could be a powerful tool for rapid biological imaging.

A newly discovered subglacial lake in East Antarctica likely hosts a valuable sedimentary record of ice and climate change

The Princess Elizabeth Land sector of the East Antarctic Ice Sheet is a significant reservoir of grounded ice and is adjacent to regions that experienced great change during Quaternary glacial cycles and Pliocene warm episodes. The existence of an extensive subglacial water system in Princess Elizabeth Land (to date only inferred from satellite imagery) bears the potential to significantly impact the thermal and kinematic conditions of the overlying ice sheet. We confirm the existence of a major subglacial lake, herein referred to as Lake Snow Eagle (LSE), for the first time using recently acquired aerogeophysical data. We systematically investigated LSE’s geological characteristics and bathymetry from two-dimensional geophysical inversion models. The inversion results suggest that LSE is located along a compressional geologic boundary, which provides reference for future characterization of the geologic and tectonic context of this region. We estimate LSE to be ~42 km in length and 370 km2 in area, making it one of the largest subglacial lakes in Antarctica. Additionally, the airborne ice-penetrating radar observations and geophysical inversions reveal a layer of unconsolidated water-saturated sediment around and at the bottom of LSE, which—given the ultralow rates of sedimentation expected in such environments—may archive valuable records of paleoenvironmental changes and the early history of East Antarctic Ice Sheet evolution in Princess Elizabeth Land.

Map analysis of morbidity and mortality from blood circulatory system diseases of the population of the Russian federation (2010-2019)

Highlights. For the first time, mapping models of morbidity and mortality from the blood circulation system diseases for assessing the performance of the health protection system in federal districts of the Russian Federation were proposed. The method makes it possible to identify low-quality health systems, and outsider regions, where it is necessary to develop measures in order to identify modifiable and non-modifiable risk factors and improve the performance of health care system both in federal districts and in the Russian Federation as a whole.Aim. To develop mapping models of morbidity and mortality from the blood circulation system diseases (BCSD) and to propose indices for assessing the performance of the health care system in different federal districts of Russia over a 10-year period (from 2010 to 2019).Methods. Reporting forms of federal statistical observation in the field of public health were used.Results. The incidence of BCSD among the population of the Russian Federation has been steadily increasing over the past two decades, increasing 2.047-fold from 2000 to 2019, while the mortality rate of the Russian population decreased 2.073-fold over the same period. Mapping models of morbidity and mortality from BCSD have been developed and indices for assessing the performance of the health protection system in different federal districts of Russia over a 10-year period (from 2010 to 2019) have been proposed.Conclusion. The mapping of low and ultra-low incidence rates of BCSD combined with high and ultra-high mortality rates from BSC among the population of the federal districts indicates low detection rates and low performance of the primary health care system in detecting BSC among the population assigned to receive primary health care according to the territorial principle. The correlation of indicators of general morbidity and mortality from HIPC in relation to health care resources allows timely assessment and finding resources in those areas that contribute to the maximum efficiency of medical organizations at minimum cost.

Stretchable Zn‐Ion Hybrid Battery with Reconfigurable V2CTx and Ti3C2Tx MXene Electrodes as a Magnetically Actuated Soft Robot (Adv. Energy Mater. 45/2021)

Zn-Ion Hybrid Batteries In article number 2101862, Yusheng Zhao, Po-Yen Chen and co-workers report stretchable Zn-Ion hybrid batteries composed of V2CTx MXene cathodes and zinc-decorated Ti3C2Tx MXene anodes with crumple-like microtextures, enabling unique folding/unfolding behaviors to attenuate in-plane stress. The stretchable Zn-ion battery is rechargeable and features large deformability, ultrathin device configuration, low areal weight, and ultralow self-discharge rates. The stretchable battery can be further transformed into a magnetically actuated soft robot with remote control, capable of crawling back and forth for charging/discharging tasks.

Genome Evolution in Bacteria Isolated from Million-Year-Old Subseafloor Sediment

ABSTRACTBeneath the seafloor, microbial life subsists in isolation from the surface world under persistent energy limitation. The nature and extent of genomic evolution in subseafloor microbes have been unknown. Here, we show that the genomes of Thalassospira bacterial populations cultured from million-year-old subseafloor sediments evolve in clonal populations by point mutation, with a relatively low rate of homologous recombination and elevated numbers of pseudogenes. Ratios of nonsynonymous to synonymous substitutions correlate with the accumulation of pseudogenes, consistent with a role for genetic drift in the subseafloor strains but not in type strains of Thalassospira isolated from the surface world. Consistent with this, pangenome analysis reveals that the subseafloor bacterial genomes have a significantly lower number of singleton genes than the type strains, indicating a reduction in recent gene acquisitions. Numerous insertion-deletion events and pseudogenes were present in a flagellar operon of the subseafloor bacteria, indicating that motility is nonessential in these million-year-old subseafloor sediments. This genomic evolution in subseafloor clonal populations coincided with a phenotypic difference: all subseafloor isolates have a lower rate of growth under laboratory conditions than the Thalassospira xiamenensis type strain. Our findings demonstrate that the long-term physical isolation of Thalassospira, in the absence of recombination, has resulted in clonal populations whereby reduced access to novel genetic material from neighbors has resulted in the fixation of new mutations that accumulate in genomes over millions of years.

Family policies, social norms and marital fertility decisions: A quasi‐experimental study

AbstractNumerous policy recommendations for increasing fertility in societies with ultralow fertility rates have been made, yet their effectiveness has mostly remained unevaluated. Using a multifactorial vignette design that creates hypothetical policy scenarios, this paper seeks to determine the effects of family‐friendly policies and organizational norms on fertility decisions in Hong Kong. Based on a territory‐wide random sample (N = 1000), we find a discrepancy between respondents’ ideal and actual number of children. All family policy recommendations, including leave policies, childcare support, housing policies and workhour legislation, may raise fertility but leave policies work better when they include fathers’ involvement instead of just mothers. Childcare support and housing policies have a positive multiplying effect on fertility. Family‐friendly organizational norms strengthen the positive effect of workhour legislation and leave policies on fertility. The effects of policies on fertility also vary by respondents’ socioeconomic status and their perception of having children.

Monetary policy’s rising FX impact in the era of ultra-low rates

We show that the impact of monetary policy on exchange rates has been growing significantly in recent years. Our results are established by a high-frequency event study of how key fixed income instruments with different maturities respond jointly with exchange rates to monetary policy news from six major central banks. Across countries, news affecting short-term maturity bonds tend to have the strongest impact, highlighting the relevance of communication regarding the path of future monetary policy for exchange rate movements even when policy rates are near their lower bound. We find that the FX impact of monetary policy is state-dependent and is stronger the lower is the level of interest rates, in line with a greater effect through currency risk premia.

Recent advances in superconducting nanowire single-photon detector technology for exoplanet transit spectroscopy in the mid-infrared

The Origins Space Telescope mission concept includes an exoplanet transit spectrometer that requires detector arrays with ultrahigh pixel-to-pixel stability. Superconducting nanowire single-photon detectors, or SNSPDs, have the potential to meet these stringent stability requirements due to their digital-like output. Traditionally used for applications at near-IR telecom wavelengths, SNSPDs have demonstrated near-unity detection efficiencies, ultralow dark-count rates, and high dynamic ranges. Until recently, however, SNSPD operation at the mid-infrared (mid-IR) wavelengths of interest for Origins had not been demonstrated, and SNSPD formats were limited to small arrays and active areas. Recent advances in SNSPD fabrication techniques have pushed SNSPD sensitivity to wavelengths beyond 7 μm and have enabled millimeter-scale active areas and kilopixel arrays. We report here on this progress and the outlook toward developing arrays of ultrastable superconducting nanowire single-photon detectors for mid-IR astronomy applications.

Characterizing corrosion properties of graphene barrier layers deposited on polycrystalline metals

In this study, barrier properties of as-grown graphene layers (Gr) were systematically characterized on two widely used polycrystalline metal substrates, copper (Cu) and nickel (Ni), under ambient humid air as well as in aggressive steam/air environments. Four types of graphene coatings were used to distinguish the bonding effect: directly grown graphene coatings on Cu and Ni as well as transferred graphene coatings on Cu and Ni. Corrosion rates were examined through Tafel analysis in both single-cycle and multiple-cycle experiments. Our study shows that in-plane diffusion of water and oxygen into underlying Cu substrates triggers corrosion of Cu surfaces even in the presence of graphene coatings. Similar corrosion caused by in-plane diffusion of corrosive species was not observed in the Ni/Gr system, which effectively protects the Ni surface in most regions under steam/air environment over 1 month. The Ni/Gr system demonstrates ultra-low and stable corrosion rates compared with those of transferred graphene on Ni (TrGr/Ni) and Cu/Gr systems in destructive corrosion evolution tests. After three cycles cumulative Tafel tests, the corrosion rates of TrGr/Ni and Cu/Gr system dramatically increased 66.3 times and 361.6 times compared to that of Ni/Gr system, respectively. This study shows that the formation of a strong metal-graphene interfacial bond plays a critical role in enabling long-term corrosion-resistant by applying graphene coatings on polycrystalline metal substrates.