4,354 research outputs found
Value Discount of Business Groups Surrounding the Asia Financial Crisis: Evidence from Korean Chaebols
Asian Financial Crisis, Business Group, Chaebol, Diversification, Firm Value
Deterioration of Eggshell Quality and Calcium Metabolism in Laying Hens
The present study was undertaken to: (1) develop a reliable method of measuring eggshell quality, (2) determine whether diet alterations that cause a somewhat reduced rate of egg production could influence shell quality, and (3) determine whether certain biochemical parameters involved in calcium metabolism are related to shell quality
Heating temperature prediction of concrete structure damaged by fire using a Bayesian approach
A fire that occurs in a reinforced concrete (RC) structure accompanies a heating temperature, and this negatively affects the concrete material properties, such as the compressive strength, the bond between cement paste and aggregate, and the cracking and spalling of concrete. To appropriately measure the reduced structural performance and durability of fire-damaged RC structures, it is important to accurately estimate the heating temperature of the structure. However, studies in the literature on RC structures damaged by fire have focused mostly on structural member tests at elevated temperatures to ensure the fire resistance or fire protection material development; studies on estimating the heating temperature are very limited except for the very few existing models. Therefore, in this study, a heating temperature estimation model for a reinforced concrete (RC) structure damaged by fire was developed using a statistical Bayesian parameter estimation approach. For the model development, a total of 77 concrete test specimens were utilized; based on them, a statistically highly accurate model has been developed. The usage of the proposed method in the framework of the 500 âŠC isotherm method in Eurocode 2 has been illustrated through an RC column resistance estimation application
Calcium Metabolism and Egg Shell Quality in Laying Hens
This experiment was designed to determine whether diet alterations that cause a somewhat reduced rate of lay could influence shell quality and whether certain chemical and biochemical measurements could be related to a decline in shell quality
Precise Numerical Solutions of Potential Problems Using Crank-Nicholson Method
A new numerical treatment in the Crank-Nicholson method with the imaginary
time evolution operator is presented in order to solve the Schr\"{o}dinger
equation. The original time evolution technique is extended to a new operator
that provides a systematic way to calculate not only eigenvalues of ground
state but also of excited states. This new method systematically produces
eigenvalues with accuracies of eleven digits with the Cornell potential that
covers non-perturbative regime. An absolute error estimation technique based on
a power counting rule is implemented. This method is examined with exactly
solvable problems and produces the numerical accuracy down to 10.Comment: 10 pages, 1 figure. Submitted to Phys. Rev. Let
Sequence-to-Sequence Prediction of Vehicle Trajectory via LSTM Encoder-Decoder Architecture
In this paper, we propose a deep learning based vehicle trajectory prediction
technique which can generate the future trajectory sequence of surrounding
vehicles in real time. We employ the encoder-decoder architecture which
analyzes the pattern underlying in the past trajectory using the long
short-term memory (LSTM) based encoder and generates the future trajectory
sequence using the LSTM based decoder. This structure produces the most
likely trajectory candidates over occupancy grid map by employing the beam
search technique which keeps the locally best candidates from the decoder
output. The experiments conducted on highway traffic scenarios show that the
prediction accuracy of the proposed method is significantly higher than the
conventional trajectory prediction techniques
Structural safety inspection of reinforced concrete structures considering failure probabilities of structural members
Regular safety inspections of existing reinforced concrete (RC) structures are required according to the regulations and criteria set by each country. In South Korea, the safety inspection regulations provided by the Korea Infrastructure Safety and Technology Corporation (KISTEC) are followed. These regulations were developed based on fuzzy theory to avoid subjective decisions, and provide standardized deterioration grades for member types, floors, and the entire structure. However, the safety inspection regulation by the KISTEC often provides unconservative evaluation results. In particular, as the importance factors of beam and slab members are set lower than those of other members, there are cases in which deteriorations occurring in beams and slabs are not properly reflected in the floor level evaluation. In this study, to overcome such limitations, case studies were carried out and modified importance factors for structural member types were proposed considering the failure probabilities of each member type based on the reliability theory. The importance modification factor was calculated based on the strength ratio of structural members so that the more dangerous the members are, the more impact they give on the evaluation. Overall, compared to the KISTEC method, the proposed method provided conservative but practical assessment results, and it was found that the proposed importance factors can be very useful to properly reflect the effects of damaged members on the deterioration status evaluation of the floors and the entire structure
Incipient piezoelectrics and electrostriction behavior in Sn-doped Bi-1/2( Na0.82K0.18)(1/2) TiO3 lead-free ceramics
Dielectric, ferroelectric, piezoelectric, and strain properties of lead-free Sn-doped Bi-1/2(Na0.82K0.18)(1/2)TiO3 (BNKT) were investigated. A crossover from a nonergodic relaxor to an ergodic relaxor state at room temperature, accompanied by a giant electric-field-induced strain, was observed at 5 at. % Sn doping. Switching dynamics monitored during a bipolar poling cycle manifested that the observed giant strain originates from incipient piezoelectricity. When Sn doping level reached 8 at. %, BNKT exhibited an electrostrictive behavior with a highly temperature-insensitive electrostrictive coefficient of Q(11) = 0.023 m(4)open3
Room-temperature polariton lasing in quantum heterostructure nanocavities
Controlling light-matter interactions in solid-state systems has motivated
intense research to produce bosonic quasi-particles known as
exciton-polaritons, which requires strong coupling between excitons and cavity
photons. Ultra-low threshold coherent light emitters can be achieved through
lasing from exciton-polariton condensates, but this generally requires
sophisticated device structures and cryogenic temperatures. Polaritonic
nanolasers operating at room temperature lie on the crucial path of related
research, not only for the exploration of polariton physics at the nanoscale
but also for potential applications in quantum information systems, all-optical
logic gates, and ultra-low threshold lasers. However, at present, progress
toward room-temperature polariton nanolasers has been limited by the thermal
instability of excitons and the inherently low quality factors of nanocavities.
Here, we demonstrate room-temperature polaritonic nanolasers by designing
wide-gap semiconductor heterostructure nanocavities to produce thermally stable
excitons coupled with nanocavity photons. The resulting mixed states of
exciton-polaritons with Rabi frequencies of approximately 370 meV enable
persistent polariton lasing up to room temperature, facilitating the
realization of miniaturized and integrated polariton systems
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