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Colloidal quantum dots (QDs) stand at the forefront of a variety of photonic applications given their narrow spectral bandwidth and near-unity luminescence efficiency. Integrating desired forms of QD films into photonic systems without compromising their optical or transport characteristics is the key to bridging the gap between expectations and outcomes. Here, we devise a dual-ligand passivation system comprising photocrosslinkable ligands and dispersing ligands to enable QDs to be universally compatible with solution-based patterning techniques. The successful control on the structure of both ligands allows multiscale, direct patterning of the dual-ligand QDs on various substrates via commercialized photolithography (i-line) or inkjet printing systems without compromising the optical properties of QDs or the optoelectronic performances of the devices implementing them. Our approach offers a versatile way of creating various structures of luminescent QDs in a cost-effective and non-destructive manner, and thus enables the implementation of QDs in a range of photonic applications.

This study examines not only the relationship between a firm’s excess cash holdings and audit effort but also the moderating effects of CEO characteristics on the relationship. Using a sample of no...

This study investigates the relationship between excess cash holdings of firms and CEO characteristics, such as ownership type, presence of stock options, inclusion in a chaebol, and CEO tenure. Based on a sample of non-financial listed Korean companies for 2000–2014, we find first, that professional CEOs have higher excess cash holdings than owner-managers have. Second, longer CEO tenure lowers excess cash holdings but decreases the marginal impact of CEO tenure on excess cash holdings. Third, the effect of CEO affiliation to a chaebol on excess cash holdings was greater before the global financial crisis of 2008–2009 than after it. Excess cash holdings arise from agency problems and the CEO horizon problem but agency problems between minority and dominant shareholders have eased in Korea since the crisis.

Background: The objective of this study was to investigate the characteristics and clinical outcomes of critically ill cancer patients admitted to intensive care units (ICUs) in Korea. Methods: This was a retrospective cohort study that analyzed prospective collected data from the Validation of Simplified Acute Physiology Score 3 (SAPS3) in Korean ICU (VSKI) study, which is a nationwide, multicenter, and prospective study that considered 5,063 pa tients from 22 ICUs in Korea over a period of 7 months. Among them, patients older than 18 years of age who were diagnosed with solid or hematologic malignancies prior to admission to the ICU were included in the present study. Results: During the study period, a total of 1,762 cancer patients were admitted to the ICUs and 833 of them were deemed eligible for analysis. Six hundred fifty-eight (79%) had solid tumors and 175 (21%) had hematologic malignancies, respectively. Respiratory problems (30.1%) was the most common reason leading to ICU admission. Patients with hematologic malignancies had higher Sequential Organ Failure Assessment (12 vs. 8, P

The composite cathode of an all-solid-state battery composed of various solid-state components requires a dense microstructure and a highly percolated solid-state interface different from that of a conventional liquid-electrolyte-based Li-ion battery. Indeed, the preparation of such a system is particularly challenging. In this study, quantitative analyses of composite cathodes by three-dimensional reconstruction analysis were performed beyond the existing qualitative analysis, and their microstructures and reaction interfaces were successfully analyzed. Interestingly, various quantitative values of structure properties (such as the volume ratio, connectivity, tortuosity, and pore formation) associated with material optimization and process development were predicted, and they were found to result in limited electrochemical charge/discharge performances. We also verified that the effective two-phase boundaries were significantly suppressed to ∼23% of the total volume because of component dispersion and packing issues.

The development and application of all-solid-state batteries with a fast lithium-ionic conductor are hampered by structural instability and rigid stoichiometry restrictions. Here, we present a family of lithium thiophosphate prototypes with a novel principle, controlling sulfur deficiencies with the addition of nickel sulfide-based additives, for fast lithium-ion conduction and distinct electrochemical stability under the extended material constituent. Well-controlled sulfur deficiency of the Li3PS4 framework accompanied by nickel sulfide additive offers the notable increase of lithium-ion conductivity (2 × 10–3 S cm–1 at 25 °C) and high electrochemical stability (up to 10 V vs Li/Li+) in a wide composition range. We further confirm the potential application of our fast composite lithium-ion conductor as an electrolyte for the all-solid-state battery with 117 mAh g–1 capacity delivery and stable cycle life.

In this paper, we first propose an efficient crosstalk-included eye-diagram estimation method for high-speed interposer channel on 2.5-D and three-dimensional (3-D) IC. The proposed method includes crosstalk effects from adjacent channels, which can considerably degrade the transmitted signal on a victim channel. This method enables to estimate worst and statistical eye-diagrams in a short time with high accuracy. While 3-D EM simulation has been widely used for accurate estimation of the channel performance, it requires substantial amount of computational time and resources. Therefore, in order to reduce the eye-diagram estimation time, the coupled microstrip channels are modeled using resistance, inductance, conductance, and capacitance components, whose values are derived from the physical dimensions. The equivalent circuit model can also enhance physical insight of the coupled channels. The proposed method is verified by time-domain simulations and measurements at data rates of up to 4 Gb/s. According to the estimated crosstalk-included eye-diagrams, the proposed method reduces simulation time over 99% and shows a high accuracy of approximately 93%. The proposed method is applied to the high-bandwidth memory channels on silicon, organic, and glass interposer.

Connected vehicles are at risk of exposing their location history when using potentially untrusted location-based services (LBSs) in the driving process. We propose a method called mutually obfuscating paths (MOP) that enables vehicles to provide highly accurate realtime location updates to LBS while preventing the LBS from tracking vehicles. The instrument is to leverage connected vehicles’ two network interfaces: in-car LTE Internet (for accessing LBS) and car-to-car Dedicated short-range communications (DSRC)-communication (for obfuscating their paths). The main idea of MOP is that vehicles, when appropriate, generate made-up but plausible location updates for each other, making their paths continuously branching off from the LBS’ viewpoint. We evaluations show that MOP provides strong privacy protection even under continuous and highly accurate location updates.

Chain-mapping techniques in combination with the time-dependent density matrix renormalization group are a powerful tool for the simulation of open-system quantum dynamics. For finite-temperature environments, however, this approach suffers from an unfavorable algorithmic scaling with increasing temperature. We prove that the system dynamics under thermal environments can be non-perturbatively described by temperature-dependent system-environmental couplings with the initial environment state being in its pure vacuum state, instead of a mixed thermal state. As a consequence, as long as the initial system state is pure, the global system-environment state remains pure at all times. The resulting speedup and relaxed memory requirements of this approach enable the efficient simulation of open quantum systems interacting with highly structured environments in any temperature range, with applications extending from quantum thermodynamics to quantum effects in mesoscopic systems., 5+5 pages, close to published version

With various IoT cameras today, sharing of their video evidences, while benefiting the public, threatens the privacy of individuals in the footage. However, protecting visual privacy without losing video authenticity is challenging. The conventional post-process blurring would open the door for posterior fabrication, whereas the realtime blurring results in poor quality, low-frame-rate videos due to the limited processing power of commodity cameras. This paper presents Pinto, a software-based solution for producing privacy-protected, forgery-proof, and high-frame-rate videos using low-end IoT cameras. Pinto records a realtime video stream at a fast rate and allows post-processing for privacy protection prior to sharing of videos while keeping their original, realtime signatures valid even after the post blurring, guaranteeing no content forgery since the time of their recording. Pinto is readily implementable in today's commodity cameras. Our prototype on three different embedded devices, each deployed in a specific application context---on-site, vehicular, and aerial surveillance---demonstrates the production of privacy-protected, forgery-proof videos with frame rates of 17--24 fps, comparable to those of HD videos.

To understand the role of myeloid differentiation factor 88 (MyD88) expressed by donor bone marrow (BM) in the pathophysiology of graft-vs.-host disease (GVHD), we investigated the effects of transplantation of MyD88-deficient T cell-depleted BM (MyD88KO TCD-BM) on the severity of GVHD. Transplantation with MyD88KO TCD-BM aggravated GVHD; serious gut damage was evident, with high infiltration of T cells into the intestines of recipients and markedly reduced expansion of CD11b(+)Gr-1(+) myeloid-derived suppressor cells (MDSCs). MDSCs from MyD88KO mice were defective in inducing donor T-cell apoptosis and inhibiting T-cell proliferation. Supplementation of transplanted mice with MDSCs from wild-type mice, but not MyD88KO mice, attenuated GVHD severity with reduced intestinal T-cell infiltration in MyD88KO TCD-BM recipients. Pretreatment of BM donors with lipopolysaccharide to increase MDSC levels and MyD88 transcription in the TCD-BM transplant alleviated GVHD severity and intestinal T-cell infiltration. The T cell/MDSC ratios were correlated with intestinal GVHD severity in both animal models and human patients. This study indicates that MyD88-dependent MDSC expansion from donor BM is critical for protection against fatal intestinal GVHD.

To develop sounding rockets that can be used for various missions, a university, research center, and two enterprises collaborated to conduct a critical-system development project on a small-scale sounding rocket. The Korea Advanced Institute of Science and Technology (KAIST) Rocket Laboratory and Space Solution Co., Ltd. collaborated to develop a hybrid rocket and a propellant-feeding system using hydrogen peroxide as an oxidizer. The KAIST Satellite Technology Research Center has developed a non-pyrotechnic recovery system, and Naraspace Technology Co., Ltd. has developed rocket avionics. Using a 2.39-m technology demonstrator that weighs 16.4 kg, the developed system has been validated at low altitudes, and the applicability of the small-scale sounding rocket has been evaluated. The combustion stability, short ignition delay, and high performance of the H2O2 hybrid rocket were confirmed through static firing and flight tests. The reliability and capacity of the non-pyrotechnic recovery system (which uses a spring) were confirmed by ground and flight tests. Perfect operation of the developed rocket avionics, such as control of the main oxidizer valve and recovery system, emergency functions, data transmission, and data storage was confirmed through ground and flight tests.

In This paper, we present an efficient crosstalk-included eye-diagram estimation with simulation and measurement results. Crosstalk level, total jitter, and eye height are analyzed from the obtained eye-diagram. Crosstalk effects show substantial impact on eye-diagram in HBM channel.

The effect of Li3PO4 coating was investigated for LiNi0.5Mn1.5O4 epitaxial thin film electrodes synthesized on SrTiO3 substrates by pulsed laser deposition (PLD). Amorphous Li3PO4 with a thickness of 1–4 nm was coated at room temperature onto 30 nm thick epitaxial LiNi0.5Mn1.5O4 thin films with (111), (110) and (100) lattice orientations. Electrodes with the surface coating exhibit high charge–discharge capacities and small capacity degradation during cycling experiments in the high voltage region. X-ray absorption near edge structure (XANES) and hard X-ray photoelectron spectroscopy (HAXPES) analyses indicate a higher manganese valence for the electrode surface of the Li3PO4 stacked LiNi0.5Mn1.5O4 film than that for the surface of a pristine LiNi0.5Mn1.5O4 film. Thus, surface coating affects the manganese valence near the electrode surface and improves the cycling characteristics.

Purpose This study described the acute hypoxemic respiratory failure (AHRF) population and identified potential modifiable markers of outcome. Methods A prospective, multicenter study was performed in 22 intensive care units (ICUs). The clinical outcomes of patients with acute respiratory distress syndrome (ARDS) were compared to the outcomes in patients with non-ARDS AHRF, and a propensity score matched analysis was performed. Results A total 837 patients with an arterial oxygen tension/fraction of inspired oxygen ratio (Pa o 2/F io 2) less than 300 mm Hg on ICU admission were included. Of these, 163 patients met the criteria defining ARDS, whereas the remaining 674 patients who had unilateral or no pulmonary opacities were classified as non-ARDS AHRF. Baseline Pa o 2/F io 2 ratio, thrombocytopenia, increased positive end-expiratory pressure (PEEP) were significantly associated with the 60-day mortality in hypoxemic respiratory failure after multivariate analysis. However, ARDS was not associated with increased 60-day mortality when independent predictors for the 60-day mortality and propensity score were controlled. In the case-control study, the 60-day mortality rate was 38.6% in the ARDS group and 32.3% in the non-ARDS AHRF group. In both patients with ARDS and non-ARDS AHRF, the mortality rate increased proportionally to a lower baseline Pa o 2/F io 2. Conclusion Lower baseline oxygenation (Pa o 2/F io 2) is a poor prognostic marker in acute hypoxemic respiratory failure.

We propose, for the first time, an explicit semiconductor physics-based through-silicon via (TSV) capacitance–voltage (CV) model. The effect of TSV CV hysteresis is demonstrated in the model, and the TSV capacitance is modeled with respect to dc bias voltage and the dimension of the TSV. The proposed model is verified by comparison to the measurement results. The effect of hysteresis in the model correlates well with the measurement results. This model can be utilized in a circuit level simulation to expand the possible application of the model to, but not limited to, hierarchical power distribution network impedance analysis, RC delay analysis, input–output power consumption analysis, and crosstalk and eye diagram simulation in any 3-D-IC systems using TSVs.

This study evaluates the association between the Eastern Cooperative Oncology Group Performance Status (ECOG-PS) and hospital mortality in general critically ill patients.This is a retrospective cohort study that analyzes prospective collected data from the Validation of Simplified acute physiology score 3 in Korean Intensive care unit study. The study population comprised patients who were consecutively admitted to participating intensive care units from July 1, 2010, to January 31, 2011. Univariate and multivariate logistic regression models were used to evaluate the effect of ECOG-PS on hospital mortality.A total of 3868 patients were included in the analysis. There was a significant trend for increasing hospital mortality as the ECOG-PS grade became higher (P.001). There was a trend of increasing adjusted odds ratio for hospital mortality, with grade 1 of PS 1.4 (95% confidence intervals [CIs], 1.0-1.8), grade 2 of PS 2.0 (95% CIs, 1.5-2.7), grade 3 of PS 2.9 (95% CIs, 2.1-4.1), and grade 4 of PS 2.5 (95% CIs, 1.6-3.9). Also, there was a significant difference in all grades. Subgroup analysis showed a trend of increasing hospital mortality regardless of the presence of cancer.Preadmission PS, assessed with ECOG-PS in critically ill patients, has prognostic value in general critically ill patients.

Low-tidal volume (TV) mechanical ventilation is an important manipulation in managing patients with acute respiratory distress syndrome (ARDS). However, there is no definite evidence to support the use of this intervention in patients with viral etiologies.A retrospective observational study of 104 patients with ARDS caused by pandemic influenza A/H1N1 infection admitted to 28 intensive care units (ICUs) in Korea was performed. Patients were categorized into 3 groups according to the TV they received: TV less than or equal to 7 mL/kg, TV greater than 7 mL/kg but less than or equal to 9 mL/kg, or TV greater than 9 mL/kg.The mean age was 55.1 years, and 55.8% were male (n = 58). Patients with TV greater than 9 mL/kg showed higher 28-day ICU mortality than the 2 other groups (vs TV7 mL/kg, P = .007 and vs 7 mL/kgTV ≤ 9 mL/kg, P = .004, respectively). Patients with TV less than or equal to 7 mL/kg required ventilators, ICU admissions, and hospitalizations for fewer days than those with TV greater than 7 mL/kg (11.4 vs 6.1 days for 28-day ventilator-free days, 9.7 vs 4.9 days for 28-day ICU-free days, and 5.2 vs 2.4 days for 28-day hospital-free days, respectively). Tidal volume greater than 9 mL/kg (hazard rate, 2.459; P = .003) and Sequential Organ Failure Assessment score (hazard rate, 1.158; P = .014) were significant predictors of 28-day ICU mortality.Low-TV mechanical ventilation still benefits patients with ARDS caused by viral pneumonia.

In this paper, eye-diagrams of High-Bandwidth Memory (HBM) interposer channel with crosstalk reduction schemes on 2.5D / 3D IC are estimated and analyzed. As data rate increases and metal-to-metal space decreases to achieve higher system bandwidth, crosstalk effects degrade the signal integrity. Therefore, estimation and reduction of the crosstalk effects are essential on HBM interposer channel. In order to estimate crosstalk effects in short time with high accuracy, PDA-based estimation method is proposed. In addition to the proposed method, wide space and guard trace with ground vias structures are suggested and compared based on the estimated eye-diagrams. With the estimated eye-diagrams, voltage fluctuation on DC levels due to the crosstalk effects can be analyzed. Worst and statistical eye-diagrams of interposer channels including crosstalk effects are estimated. Since the proposed method needs only output and crosstalk response of the channel, the proposed method can be applied to multiple wide I/O channels.

Through silicon via (TSV) based 3DIC has allowed vertical integration of multiple dies for wide I/O configuration. With thousands of TSVs, data transfer rate can be reduced, while maintaining the highest bandwidth compared to the systems in conventional integrated chips and packages. The challenges lie on high yield fabrication process. The trend in dimension of TSV is continuously decreasing, which also causes bumps and redistribution layer (RDL) to be reduced for routing high number of I/Os. In this paper, we present the equivalent circuit models and analyze the TSV channels for investigation of the effect of possible defects. The verified models are used for characterizing the defects in TSV channel, and we validate the failure analysis method with electrical characteristic analysis in frequency-domain with S-parameter plots as well as time-domain waveforms with TDR.

In this paper, a bump-less high-speed through silicon via (TSV) channel is proposed for terabyte/s bandwidth 2.5D IC. The signal integrity of the proposed channel is analyzed based on the frequency and time domain simulation. To analyze the signal integrity of the proposed channel minutely, the proposed channel and the conventional channel are simulated and compared respectively. Moreover, unlike the conventional channel, the signal integrity of the proposed channel is significantly affected by the coupling pads capacitance. Therefore, the proposed channel performance is investigated with different coupling pads capacitances.

In this paper, eye-diagrams of coupled microstrip channel on Printed Circuit Board (PCB) are estimated using equivalent circuit model. The equivalent circuit model has RLGC terms which are calculated from the physical dimensions of the coupled microstrip channel. Since the coupled microstrip channel is modeled by physical dimensions, eye-diagrams are estimated without 3D Full EM simulation, which needs long simulation time to extract channel performance. In addition, the equivalent circuit model enhances physical insight of the coupled channel and crosstalk effects. To verify the equivalent circuit model, frequency and time domain simulations are performed. As a result, worst eye-diagrams are estimated and compared with the 3D Full EM simulation.