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No full textInterunit Executive Redeployment in Multiunit Firms: Evidence from Korean Business Groups
No full textBuilding on the literature on resource reconfiguration theory, we formulate a new theoretical framework that explains how executive redeployment within a diversified firm transfers different types of human capital embodied in executives to different units facing specific business challenges. In the empirical context of Korean business groups, we find that executives with unit-specific human capital, like turnaround experience, competitive experience, and international expansion experience, are redeployed to units with corresponding business challenges like financial difficulties, intensifying competition, and early-stage international expansion, respectively. We also show that executives with unit generic human capital, like corporate management practices and interunit coordination experiences, are redeployed to younger units seeking to establish corporate-level policies and practices. Additional analyses also show that the value of firm-specific human capital in driving the redeployment of executives is contingent on their functional orientation and seniority
Large-Area Flexible Electrochromic Devices with High-Performance and Low-Power Consumption Enabled by Hydroxyhexyl Viologen- Substituted Polyhedral Oligomeric Silsesquioxane
No full textIn this work, we prepared octa-hydroxyhexyl viologen-substituted polyhedral oligomeric silsesquioxane (OHHV-POSS) as an organic-inorganic composite material applicable for large-area flexible electrochromic devices (FECDs). The organic-inorganic hybrid structure supported by the POSS cage and the enhanced interaction between hydroxyl end-groups and lithium salts can effectively increase the ionic conductivity of the ion gel films, thereby improving the electrochromic performance capabilities. Homogeneous ion gel was obtained with polyvinyl butyral and a lithium salt, and outstanding electrochromic properties were observed during electrochromic device operations. The FECDs of various sizes were fabricated for systematic evaluation, and the device of up to 22.5 x 19.5 cm2 was successfully constructed using the simple doctor blade coating method. The prepared large-area FECDs achieved a large transmittance difference of 70.0% at 604 nm, fast switching times of 21.1 and 18.0 s, high coloration efficiency of 260.61 cm2/C, long-term cycling stability of up to 300 cycles, and low power consumption of about 250 mu W/cm2. Furthermore, the device was maintained stably in various application tests for heat insulation and storage, UV resistance, and mechanical stability. High performance and low power consumption of OHHV-POSS prove suitable for large-area FECDs, suggesting promising potential for smart windows, wristbands, and eyewear products
Practical Distance-Based Multi-robot Formation Control Using Low-Cost Ultrasonic Source Tracker
No full textThis paper addresses a communication-free formation control problem for multi-robot applications. To eliminate the formation control errors of the existing nonlinear control schemes, the linear quadratic(LQ) servo technique is applied to a state-space equation which describes the relative motion of a follower robot with respect to a leader in line-of-sight(LOS) frame. Under the assumption that the leader is equipped with an omni-directional ultrasonic transmitter, a gimbaled source tracker is designed to obtain range and bearing measurements. Thus, it enables us to implement the formation controller without any data links. By exploiting the LQ servo structure, our approach not only guarantees the robustness against unmodeled robot dynamics or unknown disturbances, but also makes quantitative analysis on stability margin possible. The superior formation control performance of the proposed method is verified through experiments
Dysprosium Incorporation for Phase Stabilization of Atomic-Layer- Deposited HfO2 Thin Films
No full textThe relatively low thermal stability of HfO2 films severely affects the performance of semiconductor devices. For instance, the low crystallization temperature of HfO2 (similar to 500 degrees C) leads to the formation of grain boundaries, which increases the leakage current. In this study, Dy incorporation leads to the phase transformation of HfO2 films from various directional planes to a main m(-111) plane by the crystallographic stabilization of HfO2 films, increasing the size of grains. Dy-doped HfO2 thin films with modulated doping content, prepared by plasma-enhanced atomic layer deposition (PE-ALD), are characterized by analysis of their chemical composition combined with electron microscopy and synchrotron X-ray techniques. The transformation from m(110), m(-111), m(111), m(020), and m(120) to a main m(-111) plane is observed through X-ray diffraction, which indicates that Dy plays a role for the phase stabilization of HfO2 films. The atomic-scale images of the cross section and top view obtained using an electron microscope demonstrate that the in-plane average grain size is increased by approximately 4 times due to Dy incorporation compared with that of single HfO2 films. The reduction in the area of the grain boundary of HfO2 due to Dy incorporation decreases the leakage current density of HfO2 by 1000 times and increased the breakdown strength. This result can aid future electronics by determining the effect of a dopant on the crystallographic structure of host thin-film materials
Ultrahigh dielectric permittivity in oxide ceramics by hydrogenation
No full textBoosting dielectric permittivity representing electrical polarizability of dielectric materials has been considered a keystone for achieving scientific breakthroughs as well as technological advances in various multifunctional devices. Here, we demonstrate sizable enhancements of low-frequency dielectric responses in oxygen-deficient oxide ceramics through specific treatments under humid environments. Ultrahigh dielectric permittivity (similar to 5.2 x 10(6) at 1 Hz) is achieved by hydrogenation, when Ni-substituted BaTiO3 ceramics are exposed to high humidity. Intriguingly, thermal annealing can restore the dielectric on-state (exhibiting huge polarizability in the treated ceramics) to the initial dielectric off-state (displaying low polarizability of similar to 10(3) in the pristine ceram-ics after sintering). The conversion between these two dielectric states via the ambient environment-mediated treatments and the successive application of external stimuli allows us to realize reversible control of dielectric relaxation characteristics in oxide ceramics. Conceptually, our findings are of practical interest for applications to highly efficient dielectric-based humidity sensors
Role of adaptive intraspecific competition on collective behavior in the rock???paper???scissors game
No full textDensity-dependent selection is a universal feature in the evolution of populations, and such an adaptive behavior can change the survival strategy of species during evolution. In this paper, we investigate the role of adaptive behavior in biodiversity in the system of cyclic competition. By incorporating a density-dependent mechanism into intraspecific competition, which is well-known as a key mechanism leading to biodiversity, we studied how such adaptive intraspecific competition can affect biodiversity and collective behavior during the evolution of cyclically competing species. Microscopically, we found that species can coexist strongly and are spirally entangled or collectively united by presenting two distinct pattern formations on spatially extended systems. While the adaptive mechanism can always promote species coexistence in a mean-field manner for particular sensitivity to the group scale, corresponding spatial dynamics exhibit nonmonotonic features for the robustness of extinction at moderately high mobility regime over the critical mobility when the associated mean-field system exhibits asymptotically stable heteroclinic cycles. The findings can shed light on a new aspect of the collective behavior of coexisting populations which may indicate the possibility of changing the survival strategies of each group to maintain the coexistence of cyclically competing populations
Recombinant lignin peroxidase with superior thermal stability and melanin decolorization efficiency in a typical human skin-mimicking environment
No full textRecently, the desire for a safe and effective method for skin whitening has been growing in the cosmetics industry. Commonly used tyrosinase-inhibiting chemical reagents exhibit side effects. Thus, recent studies have focused on performing melanin decolorization with enzymes as an alternative due to the low toxicity of enzymes and their ability to decolorize melanin selectively. Herein, 10 different isozymes were expressed as recombinant lignin peroxidases (LiPs) from Phanerochaete chrysosporium (PcLiPs), and PcLiP isozyme 4 (PcLiP04) was selected due to its high stability and activity at pH 5.5 and 37 ??C, which is close to human skin conditions. In vitro melanin decolorization results indicated that PcLiP04 exhibited at least 2.9-fold higher efficiency than that of well-known lignin peroxidase (PcLiP01) in a typical human skin-mimicking environment. The interaction force between melanin films measured by a surface forces apparatus (SFA) revealed that the decolorization of melanin by PcLiP04 harbors a disrupted structure, possibly interrupting ??????? stacking and/or hydrogen bonds. In addition, a 3D reconstructed human pigmented epidermis skin model showed a decrease in melanin area to 59.8% using PcLiP04, which suggests that PcLiP04 exhibits a strong potential for skin whitening