139 research outputs found
A Latent Factor Approach for Social Network Analysis
Social network data consist of entities and the relation of information between
pairs of entities. Observations in a social network are dyadic and interdependent.
Therefore, making appropriate statistical inferences from a network requires specifications
of dependencies in a model. Previous studies suggested that latent factor
models (LFMs) for social network data can account for stochastic equivalence and
transitivity simultaneously, which are the two primary dependency patterns that are
observed social network data in real-world social networks. One particular LFM, the
additive and multiplicative effects network model (AME) accounts for the heterogeneity
of second-order dependencies at the actor level. However, all current latent
variable models have not considered the heterogeneity of third-order dependencies,
actor-level transitivity for example. Failure to model third-order dependency heterogeneity
may result in worse fits to local network structures, which in turn may result
in biased parameter inferences and may negatively influence the goodness-of-fit and
prediction performance of a model.
Motivated by such a gap in the literature, this dissertation proposes to incorporate
a correlation structure between the sender and receiver latent factors in the
AME to account for the distribution of actor-level transitivity. The proposed model
is compared with the existing AME in both simulation studies real-world data. Models
are evaluated via multiple goodness-of-fit techniques, including mean squared error,
parameter coverage rate, information criteria, receiver-operation curve (ROC)
based on K-fold cross-validation or full data, and posterior predictive checking. This
work may also contribute to the literature of goodness-of-fit methods to network
models, which is an area that has not been unified.
Both the simulation studies and real-world data analyses showed that adding
the correlation structure provides a better fit as well as higher prediction accuracy
to network data. The proposed method has equal or similar performance to the
AME when the underlying correlation is zero, with regard to mean-squared error
of probability of ties and widely applicable information criteria. The present study
did not find any significant impact of the correlation term on the node-level covariateâs
coefficient estimation. Future studies include investigating more types of covariates,
subgroup related covariate effects is an example
A Comparative Research on Competitiveness of Information Industry of China vs. Korea
This paper explores the competitiveness of information industry of China and Korea by means of comparative research based on the analysis of statistic data and the definition of items denoting the competitiveness. Consequently, we analyze the competitive and complementary relation of information industry of China vs. Korea, and put forward a co-operation project of China-Korea information industry ultimately
Digital LLRF system for TRIUMF ISIS buncher
The ISIS buncher system at TRIUMF operates at frequencies of 23MHz, 46MHz,
and 4.6MHz. The 23MHz and 46MHz signals drive two buncher cavities, while the
4.6MHz signal drives the 5:1 selector. The previous analog-digital hybrid
system has been replaced with a new digital LLRF system due to occasional
drifts in the setpoints of the control loops during operation. The reference
signal for the LLRF system is obtained from the pickup signal of the
cyclotron's cavity, ensuring that all frequencies are synchronized with it. In
the event of a spark occurring in the cyclotron's cavity, the LLRF system may
lose its reference signal. To address this, a phase-locked loop with a track
and hold function is designed to maintain the frequency when the reference
signal is absent. The 4.6MHz frequency is derived by dividing the 23MHz
reference signal frequency by 5. Designing the divide-by-5 circuitry posed
specific challenges in a binary system. The LLRF system is built upon TRIUMF's
versatile digital LLRF hardware system, with firmware optimized specifically
for the ISIS buncher system. This paper will delve into the details of the
hardware and firmware.Comment: Poster presented at LLRF Workshop 2023 (LLRF2023, arXiv: 2310.03199
Kaposiâs sarcoma-associated herpesvirus seropositivity is associated with type 2 diabetes mellitus: A caseâcontrol study in Xinjiang, China
Objective: To assess the potential relationship between Kaposiâs sarcoma-associated herpesvirus (KSHV) infection and type 2 diabetes mellitus (DM-2) in Xinjiang, China.
Methods: A caseâcontrol study of consecutively included DM-2 patients and normal controls was conducted among the Uygur and Han populations in Xinjiang Uygur Autonomous Region, China. Blood samples were collected and KSHV seroprevalence, antibody titers, and viral load were investigated. Logistic regression analysis and multiple linear regression analysis were applied to explore determinants of the main outcome measures.
Results: A total of 324 patients with DM-2 and 376 normal controls were included. The seroprevalence of KSHV was 49.1% (95% confidence interval (CI) 43.6â54.5%) for diabetic patients and 23.7% (95% CI 19.4â 28.0%) for the control group. After adjusting for variables of ethnicity, sex, body mass index, occupation, educational level, marital status, age, and smoking and alcohol consumption habits, the association between DM-2 and KSHV infection still existed (odds ratio (OR) 2.94, 95% CI 2.05â4.22), and the risk of KSHV infection increased with glucose concentration (OR 1.35, 95% CI 1.21â1.51). KSHV was more likely to express both the latent and lytic antigens in diabetic patients (latent: OR 3.27, 95% CI 2.25â4.75; lytic: OR 3.99, 95% CI 2.68â5.93). Antibody titers and viral load increased in patients with higher blood glucose levels (p \u3c 0.001).
Conclusions: Patients with DM-2 have an elevated risk of KSHV infection. Both antibody titers and viral load increased with blood glucose levels
A Novel Non-Volatile Inverter-based CiM: Continuous Sign Weight Transition and Low Power on-Chip Training
In this work, we report a novel design, one-transistor-one-inverter (1T1I),
to satisfy high speed and low power on-chip training requirements. By
leveraging doped HfO2 with ferroelectricity, a non-volatile inverter is
successfully demonstrated, enabling desired continuous weight transition
between negative and positive via the programmable threshold voltage (VTH) of
ferroelectric field-effect transistors (FeFETs). Compared with commonly used
designs with the similar function, 1T1I uniquely achieves pure on-chip-based
weight transition at an optimized working current without relying on assistance
from off-chip calculation units for signed-weight comparison, facilitating
high-speed training at low power consumption. Further improvements in linearity
and training speed can be obtained via a two-transistor-one-inverter (2T1I)
design. Overall, focusing on energy and time efficiencies, this work provides a
valuable design strategy for future FeFET-based computing-in-memory (CiM)
ZHENG-Omics Application in ZHENG Classification and Treatment: Chinese Personalized Medicine
With the hope to provide an effective approach for personalized diagnosis and treatment clinically, traditional chinese medicine (TCM) is being paid increasing attention as a complementary and alternative medicine. It performs treatment based on ZHENG (TCM syndrome) classification, which could be identified clinical special phenotypes by symptoms and signs of patients even if they have a different disease. However, it caused controversy because ZHENG classification only depends on observation, knowledge, and clinical experience of TCM practitioners, which lacks objectivity and repeatability. Although researchers and scientists of TCM have done some work with a lot of beneficial methods, the results could not reach satisfactory with the shortcomings of generalizing the entire state of the body or ignoring the patients' feelings. By total summary, mining, and integration of existing researches, the present paper attempts to introduce a novel macro-microconcept of ZHENG-omics, with the prospect of bright future in providing an objective and repeatable approach for Chinese personalized medicine in an effective way. In this paper, we give the brief introduction and preliminary validation, and discuss strategies and system-oriented technologies for achieving this goal
Preâsymptomatic transmission of novel coronavirus in community settings
We used contact tracing to document how COVIDâ19 was transmitted across 5 generations involving 10 cases, starting with an individual who became ill on January 27. We calculated the incubation period of the cases as the interval between infection and development of symptoms. The median incubation period was 6.0Â days (interquartile range, 3.5â9.5Â days). The last two generations were infected in public places, 3 and 4Â days prior to the onset of illness in their infectors. Both had certain underlying conditions and comorbidity. Further identification of how individuals transmit prior to being symptomatic will have important consequences.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163478/2/irv12773.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163478/1/irv12773_am.pd
Association of C-Reactive Protein/Albumin Ratio With Mortality in Patients With Traumatic Brain Injury: A Systematic Review and Meta-Analysis
Objective: This study examines the C-reactive protein (CRP)/albumin ratio (CAR) as an inflammation-based prognostic score for predicting mortality in patients with Traumatic Brain Injury (TBI). Methods: We systematically searched the electronic databases PubMed, Embase, and Cochrane up to February 2024. Our inclusion criteria encompassed studies investigating CAR-predicted mor- tality in patients with TBI. We calculated the Odds Ratio (OR) and associated 95 % confidence intervals (95 % CI) using a random-effects model. Quality assessment of the included studies was appraised using a NewcastleâOttawa scale. Results: A total of five studies comprising 1040 patients were included in this meta-analysis. The pooled results indicated that CAR was associated with mortality in patients with TBI (OR = 1.88, 95 % CI: 1.05â3.36, P \u3c 0.0001). The findings of subgroup analysis indicated that the relationship between CAR and mortality in patients with TBI did not vary with the severity of the condition. Conclusions: CAR emerges as a valuable prognostic tool for mortality in patients with TBI, underscoring its potential role in early risk stratification and management strategies
Integrated Optical Vortex Microcomb
The explorations of physical degrees of freedom with infinite
dimensionalities, such as orbital angular momentum and frequency of light, have
profoundly reshaped the landscape of modern optics with representative photonic
functional devices including optical vortex emitters and frequency combs. In
nanophotonics, whispering gallery mode microresonators naturally support
orbital angular momentum of light and have been demonstrated as on-chip
emitters of monochromatic optical vortices. On the other hand, whispering
gallery mode microresonators serve as a highly efficient nonlinear optical
platform for producing light at different frequencies - i.e., microcombs. Here,
we interlace the optical vortices and microcombs by demonstrating an optical
vortex comb on an III-V integrated nonlinear microresonator. The
angular-grating-dressed nonlinear microring simultaneously emits spatiotemporal
light springs consisting of 50 orbital angular momentum modes that are each
spectrally addressed to the frequency components (longitudinal whispering
gallery modes) of the generated microcomb. We further experimentally generate
optical pulses with time-varying orbital angular momenta by carefully
introducing a specific intermodal phase relation to spatiotemporal light
springs. This work may immediately boost the development of integrated
nonlinear/quantum photonics for exploring fundamental optical physics and
advancing photonic quantum technology.Comment: To appear in Nature Photonic
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