1,352 research outputs found
A Magneto-Mechanical Piezoelectric Energy Harvester Designed to Scavenge AC Magnetic Field from Thermal Power Plant with Power-Line Cables
Piezoelectric energy harvesters have attracted much attention because they are crucial in portable industrial applications. Here, we report on a high-power device based on a magneto-mechanical piezoelectric energy harvester to scavenge the AC magnetic field from a power-line cable for industrial applications. The electrical output performance of the harvester (×4 layers) reached an output voltage of 60.8 Vmax, an output power of 215 mWmax (98 mWrms), and a power density of 94.5 mWmax/cm3 (43.5 mWrms/cm3) at an impedance matching of 5 kΩ under a magnetic field of 80 μT. The multilayer energy harvester enables high-output performance, presenting an obvious advantage given this improved level of output power. Finite element simulations were also performed to support the experimental observations. The generator was successfully used to power a wireless sensor network (WSN) for use on an IoT device composed of a temperature sensor in a thermal power station. The result shows that the magneto-mechanical piezoelectric energy harvester (MPEH) demonstrated is capable of meeting the requirements of self-powered monitoring systems under a small magnetic field, and is quite promising for use in actual industrial applications
Measurement of Planetary Boundary Layer Winds with Scanning Doppler Lidar
The accurate measurement of wind profiles in the planetary boundary layer (PBL) is important not only for numerical weather prediction, but also for air quality modeling. Two wind retrieval methods using scanning Doppler light detection and ranging (lidar) measurements were compared and validated with simultaneous radiosonde soundings. A comparison with 17 radiosonde sounding profiles showed that the sine-fitting method was able to retrieve a larger number of data points, but the singular value decomposition method showed significantly smaller bias (0.57 m s(-1)) and root-mean-square error (1.75 m s(-1)) with radiosonde soundings. Increasing the averaging time interval of radial velocity for obtaining velocity azimuth display scans to 15 min resulted in better agreement with radiosonde soundings due to the signal averaging effect on noise. Simultaneous measurements from collocated wind Doppler lidar and aerosol Mie-scattering lidar revealed the temporal evolution of PBL winds and the vertical distribution of aerosols within the PBL
Regulation of thymus-dependent and thymus-independent production of immunoglobulin G subclasses by Galpha12 and Galpha13
A Flexible Piezoelectric Energy Harvester-Based Single-Layer WS2 Nanometer 2D Material for Self-Powered Sensors
A piezoelectric sensor is a typical self-powered sensor. With the advantages of a high sensitivity, high frequency band, high signal-to-noise ratio, simple structure, light weight, and reliable operation, it has gradually been applied to the field of smart wearable devices. Here, we first report a flexible piezoelectric sensor (FPS) based on tungsten disulfide (WS2) monolayers that generate electricity when subjected to human movement. The generator maximum voltage was 2.26 V, and the produced energy was 55.45 μJ of the electrical charge on the capacitor (capacity: 220 μF) when applying periodic pressing by 13 kg. The generator demonstrated here can meet the requirements of human motion energy because it generates an average voltage of 7.74 V (a knee), 8.7 V (a sole), and 4.58 V (an elbow) when used on a running human (weight: 75 kg). Output voltages embody distinct patterns for different human parts, the movement-recognition capability of the cellphone application. This generator is quite promising for smart sensors in human–machine interaction detecting personal movement
Query-Efficient Black-Box Red Teaming via Bayesian Optimization
The deployment of large-scale generative models is often restricted by their
potential risk of causing harm to users in unpredictable ways. We focus on the
problem of black-box red teaming, where a red team generates test cases and
interacts with the victim model to discover a diverse set of failures with
limited query access. Existing red teaming methods construct test cases based
on human supervision or language model (LM) and query all test cases in a
brute-force manner without incorporating any information from past evaluations,
resulting in a prohibitively large number of queries. To this end, we propose
Bayesian red teaming (BRT), novel query-efficient black-box red teaming methods
based on Bayesian optimization, which iteratively identify diverse positive
test cases leading to model failures by utilizing the pre-defined user input
pool and the past evaluations. Experimental results on various user input pools
demonstrate that our method consistently finds a significantly larger number of
diverse positive test cases under the limited query budget than the baseline
methods. The source code is available at
https://github.com/snu-mllab/Bayesian-Red-Teaming.Comment: ACL 2023 Long Paper - Main Conferenc
Bloody nipple discharge in an infant
Although milky nipple discharge appears frequently in infants, bloody nipple discharge is a very rare finding. We experienced a 4-month-old, breast-fed infant who showed bilateral bloody nipple discharge with no signs of infection, engorgement, or hypertrophy. The infant's hormonal examination and coagulation tests were normal, and an ultrasound examination revealed mammary duct ectasia. The symptoms resolved spontaneously within 6 weeks without any specific treatment, except that we advised the mother to refrain from taking herbal medicine. Since no such case has been previously reported in Korea, we present this case with a brief review of the literature
Staphylococcal enterotoxin sensitization in a community-based population : a potential role in adult-onset asthma
Background: Recent studies suggest that Staphylococcus aureus enterotoxin sensitization is a risk factor for asthma. However, there is a paucity of epidemiologic evidence on adult-onset asthma in community-based populations.
Objective: We sought to evaluate the epidemiology and the clinical significance of staphylococcal enterotoxin sensitization in community-based adult populations.
Methods: The present analyses were performed using the baseline data set of Korean adult population surveys, consisting of 1080 adults (mean age=60.2years) recruited from an urban and a rural community. Questionnaires, methacholine challenge tests, and allergen skin tests were performed for defining clinical phenotypes. Sera were analysed for total IgE and enterotoxin-specific IgE using ImmunoCAP.
Results: Staphylococcal enterotoxin sensitization (0.35kU/L) had a prevalence of 27.0%. Risk factors were identified as male sex, current smoking, advanced age (61years), and inhalant allergen sensitization. Current asthma was mostly adult onset (18years old) and showed independent associations with high enterotoxin-specific IgE levels in multivariate logistic regression tests. In multivariate linear regressions, staphylococcal enterotoxin-specific IgE level was identified as the major determinant factor for total IgE level.
Conclusions and Clinical Relevance: Staphylococcal enterotoxin sensitization was independently associated with adult-onset asthma in adult community populations. Strong correlations between the enterotoxin-specific IgE and total IgE levels support the clinical significance. The present findings warrant further studies for the precise roles of staphylococcal enterotoxin sensitization in the asthma pathogenesis
Prognostic Significance of Proliferating Cell Nuclear Ant igen Exp ress ion in Soft Tissue Sarcomas of the Extremities
We analysed 40 patients with soft tissue sarcomas (STS) of the
extremities to investigate the prognostic significance of the growth fraction of the
tumor. The patients consisted of 27 males and 13 females, and the ages ranged
from 18 to 70 years (median 46.9 years). Tumors were located in the thigh (47.
5%), forearm (15%), buttock (10%), shoulder (10%), axilla (5%), arm (5%), lower
leg (5%), and foot (2.5%) in a descending order of frequency. Histologically,
malignant fibrous histiocytoma (25%) and liposarcoma (25%) were the most
common types, followed by synovial sarcoma (17.5%), malignant schwannoma
(10%), and rhabdomyosarcoma (5%). Local recurrence ranging from 1 to 4 times
(average 1.7 times) was noted in 18 cases (45%). Distant metastasis was found in
5 out of 30 patients (16.7%), and the lung, liver, and abdominal wall were the
predilection sites. Cumulative survival rates of all STS studied were 76% and
58% in 2 years and 5 years, respectively. Univariate analysis revealed that
patient's age, surgical stage, histologic grade, differentiation of tumor cells,
mitotic count, and proliferative index were related to survival. Among known
parameters of histologic grading, only mitotic count was correlated with
proliferative index. Multivariate analysis showed that patient's age, surgical stage
and proliferative index were significant prognostic factors. This study indicates
that the proliferative index using the antibody against proliferating cell nuclear
antigen is useful to assess the prognosis of STS
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