523 research outputs found
Stochastic quantization and holographic Wilsonian renormalization group of conformally coupled scalar in AdS
In this paper, we explore the relationship between holographic Wilsonian
renormalization groups and stochastic quantization in conformally coupled
scalar theory in AdS. The relationship between these two different
frameworks is firstly proposed in arXiv:1209.2242 and tested in various free
theories. However, research on the theory with interactions has recently begun.
In this paper, we show that the stochastic four-point function obtained by the
Langevin equation is completely captured by the holographic quadruple trace
deformation when the Euclidean action is given by
where is the holographic on-shell action in the conformally coupled
scalar theory in AdS.Comment: 17+1 page
Hidden phases born of a quantum spin liquid: Application to pyrochlore spin ice
Quantum spin liquids (QSLs) have generated considerable excitement as phases of matter with emergent gauge structures and fractionalized excitations. In this context, phase transitions out of QSLs have been widely discussed as Higgs transitions from deconfined to confined phases of a lattice gauge theory. However, the possibility of a wider range of novel phases, occurring between these two limits, has yet to be systematically explored. In this Research Letter, we develop a formalism which allows for interactions between fractionalized quasiparticles coming from the constraint on the physical Hilbert space and can be used to search for exotic, hidden phases. Taking pyrochlore spin ice as a starting point, we show how a U(1) QSL can give birth to abundant daughter phases, without the need for fine-tuning of parameters. These include a (charged) Z2 QSL and a supersolid. We discuss implications for experiment, and numerical results which support our analysis. These results are of broad relevance to QSLs subject to a parton description and offer a useful perspective in the search for exotic hidden phases in quantum magnets.journal articl
Why should we switch chest compression providers every 2 minutes during cardiopulmonary resuscitation?
Objective. Tis study was conducted to determine whether trained male rescuers could maintain adequate chest compression depth (CCD) for longer than the current recommended guidelines of 2 minutes.
Methods. Forty male medical doctors administered a 5-minute single rescuer cardiopulmonary resuscitation (CPR) to a manikin on the foor with conventional CPR or randomly administered continuous chest compressions (CCC). Te ratio of compression to ventilation was set to
30:2 with mouth-to-mouth technique during conventional CPR. Chest compression data were recorded with an accelerometer
device and divided into 1-minute segments for analysis.
Results. Although average CCD maintained the recommended depths throughout 5 minutes in conventional CPR, it decreased signifcantly with CCC (1 minute: 55.4 ± 4.5 mm; 2 minutes: 54.2 ± 5.4 mm;
3 minutes: 52.6 ± 5.6 mm; 4 minutes: 51.6 ± 5.5 mm; 5 minutes: 49.9 ± 5.8 mm, p < 0.001). Te average chest compression
numbers (ACCN) per minute were maintained over 80/min and have not been changed signifcantly within 5 minutes in the CCC. However, it didn’t reach to the 80/min and decreased signifcantly afer 3minutes compared to the baseline ACCN during frst 1-minute segment in the conventional CPR. Conclusions. Despite the chest compression providers being limited to trained male medical doctors, the average CCD
decreased signifcantly within 5minutes with CCC. Although maintaining adequate CCD, ACCN in each minute decreased signifcantly afer 3minutes in the conventional CPR. Terefore, we should rotate chest
compression providers every 2minutes regardless of the rescuer’s qualifcations and
CPR methods
Shear Strength of Reinforced Concrete Columns Retrofitted by Glass Fiber Reinforced Polyurea
Aged structures and structures constructed based on outdated non-seismic design codes should be retrofitted to enhance their strength, ductility, and durability. This study evaluates the structural performance of reinforced concrete (RC) columns enhanced via polyurea or glass fiber reinforced polyurea (GFRPU) strengthening. Four RC column specimens, including a reference specimen (an unstrengthened column), were tested to evaluate the parameters of the strengthening materials and the strengthened area. The tests were carried out under a combined constant axial compressive load and quasi-static cyclic loading. The experimental results show that the composite strengthening provides lateral confinement to the columns and leads to enhanced ductility, shear-resistance capacity, and dissipated energy. The shear strength provided by the composites depends on the degree of lateral confinement achieved by the composite coating. The specimens finally failed through the development of diagonal tension cracks within the potential plastic hinge regions. The specimen treated with GFRPU strengthening showed greater strength and dissipated more energy than the specimen treated with polyurea strengthening. Furthermore, by modifying ATC-40, this study proposed an equation to estimate the shear capacity provided by the composites
Source/Drain Patterning FinFETs as Solution for Physical Area Scaling Toward 5-nm Node
A novel and feasible process scheme to downsize the source/drain (S/D) epitaxy of 5-nm node bulk fin-shaped field-effect transistors (FinFETs) were introduced by using fully-calibrated TCAD for the first time. The S/D epitaxy formed by selective epitaxial growth was diamond-shaped and occupied a large proportion of the device size irrespective of the active channel area. However, this problem was solved by patterning the low-k regions prior to S/D formation by preventing the lateral overgrowth of S/D epitaxy; the so-called S/D patterning (SDP). Its smaller S/D epitaxy decreased the average longitudinal channel stresses and drive currents for NFETs. However, the small diffusions of the boron dopants into the channel regions improved the short-channel effects and alleviated the drive current reduction for PFETs. Gate capacitances decreased greatly by reducing outer-fringing capacitances between the metal-gate stack and S/D regions. Through SPICE simulation based on the virtual source model, operation frequencies and dynamic powers of 15-stage ring oscillators were studied. SDP FinFETs have better circuit performances than the conventional and bottom oxide bulk FinFETs along with smaller active areas, promising for further area scaling through simple and reliable S/D process.11Ysciescopu
Analysis of Online Home Training Users’ Behavioral Intention and Use Behavior Based on the UTAUT Model: Moderating Roles of Risk Perception toward the COVID-19 Infection and Generational Difference
PURPOSE This study aimed (1) to analyze the behavioral intention and use behavior among the consumers of online home training contents via YouTube by employing the unified theory of acceptance and use of technology (UTAUT); (2) to test the moderating effects of risk perception toward the coronavirus (COVID-19) infection, and 3) to test differential impacts of generational difference across millennial and baby boom generations. METHODS A total of 400 questionnaires were distributed, and 383 samples were used for the final analysis after excluding 17 incomplete responses. Data were analyzed using the SPSS 25.0 and AMOS 22.0. RESULTS It was found that (1) the performance expectancy, the effort expectancy, and the social influence had positive effects on behavioral intention; (2)the facilitating condition had negative effects on the use behavior; (3) the behavioral intention had positive impact on the use behavior. Moreover, the risk perception toward the COVID-19 infection did not have moderating impacts on the UTAUT model, whereas generational differences did. CONCLUSIONS Our results suggest that the marketing strategy that improves exercise performance, convenience, and social influencing factors may be key to home training customers' behavioral intention and use behavior. Furthermore, home training material makers should recognize that the features and infrastructure required for the two generations are distinct and develop a separate marketing strategy for each
Development of a standardized in-hospital cardiopulmonary resuscitation set-up
Objective. This study evaluated whether
chest compression in a standardized inhospital
cardiopulmonary resuscitation
(CPR) set-up can be performed as effectively
as when the rescuer is kneeling beside
the patient lying on the floor. Specifically,
the in-hospital test was standardized
according to the rescuers’ average knee
height.
Methods. Experimental intervention (test
1) was a standardized, in-hospital CPR
set-up: first, the bed height was fixed at 70
cm. Second, the height difference between
the bed and a step stool was set to the average
knee height of the CPR team members
(45 cm). Control intervention (test 2) was
kneeling on floor. Thirty-eight medical
doctors on the CPR team each performed
2 minutes of chest compressions in test 1
and 2 in random order (cross-over trial). A
Little Anne was used as a simulated patient
who had experienced cardiac arrest. Chest
compression parameters, such as average
depth and rate, were measured using an accelerometer
device.
Results. In all tests, the average depths were
those recommended in the most recent
CPR guidelines (50–60 mm); there were no
significant differences between Tests 1 and
2 (53.1 ± 4.3 mm vs. 52.6 ± 4.8 mm, respectively;
p = 0.398). The average rate in Test
2 (119.1 ± 12.4 numbers/min) was slightly
faster than that in Test 1 (116.4 ± 10.2 numbers/
min; p = 0.028). No differences were
observed in any other parameters.
Conclusions. Chest compression quality in
our standardized in-hospital CPR set-up
was similar with that performed in a kneeling
position on the floor.
Trial Registration: Clinical Research Information
Service: KCT000159
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