Two ETFs were listed to track the secondary-battery industry on 12 September 2018 in the Korea Stock Exchange market. They are virtually identical except that one is designed by humans while the ...other is made by machines. This paper compares the two ETFs and find little difference in their investment strategies except that machines are more likely to pick high book-to-market stocks than humans. Machines are also more likely to pick past losers and outperform human-designed ETF afterwards. The results suggest that machines can do equally good as humans as ETF/index designers.
Generalized structured component analysis (GSCA) is a theoretically well-founded approach to component-based structural equation modeling (SEM). This approach utilizes the bootstrap method to ...estimate the confidence intervals of its parameter estimates without recourse to distributional assumptions, such as multivariate normality. It currently provides the bootstrap percentile confidence intervals only. Recently, the potential usefulness of the bias-corrected and accelerated bootstrap (BCa) confidence intervals (CIs) over the percentile method has attracted attention for another component-based SEM approach—partial least squares path modeling. Thus, in this study, we implemented the BCa CI method into GSCA and conducted a rigorous simulation to evaluate the performance of three bootstrap CI methods, including percentile, BCa, and Student's
t
methods, in terms of coverage and balance. We found that the percentile method produced CIs closer to the desired level of coverage than the other methods, while the BCa method was less prone to imbalance than the other two methods. Study findings and implications are discussed, as well as limitations and directions for future research.
The construction industry experiences the highest rate of casualties from safety-related accidents at construction sites despite continuous social interest in safety management. Accordingly, various ...studies have been conducted on safety management, wherein recent studies have focused on its integration with Machine Learning (ML). In this study, we proposed a technology for recognizing struck-by hazards between construction equipment and workers, where a Convolutional Neural Network (CNN) and sound recognition were combined to analyze the changes in the Doppler effect caused by the movements of a subject. An experiment was conducted to evaluate the recognition performance in indoor and outdoor environments with respect to movement state, direction, speed, and near-miss situations. The proposed technology was able to classify the movement direction and speed with 84.4-97.4% accuracy and near-misses with 78.9% accuracy. This technology can be implemented using data obtained through the microphone of a smartphone, thus it is highly applicable and is also effective at ensuring that a worker becomes aware of a struck-by hazard near construction equipment. The findings of this study are expected to be applicable for the prevention of struck-by accidents occurring in various forms at construction sites in the vicinity of construction equipment.
A
bstract
We use the superconformal bootstrap to derive exact relations between OPE coefficients in three-dimensional superconformal field theories with
N
≥
4
supersymmetry. These relations follow ...from a consistent truncation of the crossing symmetry equations that is associated with the cohomology of a certain supercharge. In
N
=
4
SCFTs, the non-trivial cohomology classes are in one-to-one correspondence with certain half-BPS operators, provided that these operators are restricted to lie on a line. The relations we find are powerful enough to allow us to determine an infinite number of OPE coefficients in the interacting SCFT (U(2)
2
×
U(1)
−2
ABJ theory) that constitutes the IR limit of
O
(3)
N
=
8
super-Yang-Mills theory. More generally, in
N
=
8
SCFTs with a unique stress tensor, we are led to conjecture that many superconformal multiplets allowed by group theory must actually be absent from the spectrum, and we test this conjecture in known
N
=
8
SCFTs using the superconformal index. For generic
N
=
8
SCFTs, we also improve on numerical bootstrap bounds on OPE coefficients of short and semi-short multiplets and discuss their relation to the exact relations between OPE coefficients we derived. In particular, we show that the kink previously observed in these bounds arises from the disappearance of a certain quarter-BPS multiplet, and that the location of the kink is likely tied to the existence of the U(2)
2
×
U(1)
−2
AJ theory, which can be argued to not possess this multiplet.
Abstract
This study provides a novel approach to understand human perception changes in their experiences of and interactions with public greenspaces during the early months of COVID-19. Using social ...media data and machine learning techniques, the study delivers new understandings of how people began to feel differently about their experiences compared to pre-COVID times. The study illuminates a renewed appreciation of nature as well as an emerging but prominent pattern of emotional and spiritual experiences expressed through a social media platform. Given that most park and recreational studies have almost exclusively examined whether park use increased or decreased during the pandemic, this research provides meaningful implications beyond the simple extensional visit pattern and lends weight to the growing evidences on changing perceptions over and the positive psychological impacts of nature. The study highlights the preeminent roles parks and greenspaces play during the pandemic and guides a new direction in future park development to support more natural elements and nature-oriented experiences from which emotional and spiritual well-being outcomes can be drawn.
Recent advances in functional neuroimaging techniques, including methodologies such as fNIRS, have enabled the evaluation of inter-brain synchrony (IBS) induced by interpersonal interactions. ...However, the social interactions assumed in existing dyadic hyperscanning studies do not sufficiently emulate polyadic social interactions in the real world. Therefore, we devised an experimental paradigm that incorporates the Korean folk board game "Yut-nori" to reproduce social interactions that emulate social activities in the real world. We recruited 72 participants aged 25.2 ± 3.9 years (mean ± standard deviation) and divided them into 24 triads to play Yut-nori, following the standard or modified rules. The participants either competed against an opponent (standard rule) or cooperated with an opponent (modified rule) to achieve a goal efficiently. Three different fNIRS devices were employed to record cortical hemodynamic activations in the prefrontal cortex both individually and simultaneously. Wavelet transform coherence (WTC) analyses were performed to assess prefrontal IBS within a frequency range of 0.05-0.2 Hz. Consequently, we observed that cooperative interactions increased prefrontal IBS across overall frequency bands of interest. In addition, we also found that different purposes for cooperation generated different spectral characteristics of IBS depending on the frequency bands. Moreover, IBS in the frontopolar cortex (FPC) reflected the influence of verbal interactions. The findings of our study suggest that future hyperscanning studies should consider polyadic social interactions to reveal the properties of IBS in real-world interactions.
In this paper, we provide a sufficient condition for a curve on a surface in \mathbb {R}^3 to be given by an orthogonal intersection with a sphere. This result makes it possible to express the ...boundary condition entirely in terms of the Weierstrass data without integration when dealing with free boundary minimal surfaces in a ball \mathbb {B}^3. Moreover, we show that the Gauss map of an embedded free boundary minimal annulus is one to one. By using this, the Fraser-Li conjecture can be translated into the problem of determining the Gauss map. On the other hand, we show that the Liouville type boundary value problem in an annulus gives some new insight into the structure of immersed minimal annuli orthogonal to spheres. It also suggests a new PDE theoretic approach to the Fraser-Li conjecture.
Background Despite representing nearly 20% of the U.S. population, individuals with disabilities are invisible in obesity surveillance and intervention efforts. Purpose The current study (1) compares ...obesity and extreme obesity prevalence between Americans with and without disabilities and (2) examines the association between BMI category and weight-related chronic disease risk factors in both groups. Methods In 2012, six waves of data from the National Health and Nutrition Examination Survey (NHANES, 1999–2010) were pooled to compare the prevalence of obesity and extreme obesity between adults (aged ≥20 years, N=31,990) with disabilities ( n =11,556) versus without disabilities ( n = 20,434). Chronic disease risk factors (blood pressure, lipids, C-reactive protein CRP, glucose) were compared across weight categories, by disability severity, and disability status. Results Obesity (41.6%) and extreme obesity (9.3%) prevalence among those with disabilities were significantly higher than they were among those without disabilities (29.2% and 3.9%, respectively). Disability severity and disability status negatively affected nearly all chronic disease risk factors. Additionally, there was a disability-by-weight interaction: people with disabilities at all weight categories were significantly more likely to report being told they had hypertension, high cholesterol, or diabetes and to have been prescribed antihypertensive and lipid-lowering medications. Conclusions The prevalence of obesity (41.6%) and extreme obesity (9.3%) found in individuals with disabilities is high. When compared to obese adults without disabilities, obese adults with disabilities are more likely to have diabetes, high cholesterol, hypertension, and higher CRP. Thus, the study provides convincing evidence of obesity-related health disparities between Americans with and without disabilities.
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