293 research outputs found
The Impact of IOS Use and Interpersonal Ties on Digital Innovation: Insights from Boundary Spanning and Institutional Theories
Drawing upon the boundary spanning and institutional theories, this study investigates the influence of interorganizational systems (IOS) use and interpersonal ties between a firm and its suppliers on a firm’s digital innovation and how such effects are moderated by institutional distance between the firm and its suppliers. Based on a pilot test of 123 Chinese firms, our results find that a firm’s use of IOS significantly improves its digital innovation, while interpersonal ties between the firm and its suppliers do not significantly improve the firm’s digital innovation. Further, we find that institutional distance between the firm and its suppliers differentially moderates the influences of IOS use and interpersonal ties on digital innovation. Specifically, institutional distance negatively moderates the impact of IOS use on digital innovation yet positively moderates the impact of interpersonal ties on digital innovation. We further discuss the theoretical contributions and managerial implications of the current study
A simulation study of support break-off and water inrush during mining under the high confined and thick unconsolidated aquifer
The thick Cenozoic unconsolidated aquifer is deposited under Sunan syncline core in Huaibei coalfield, the water yield property of unconsolidated bottom aquifer is strong and water pressure is high in some areas (up to 4 MPa in some areas). Water inrush accident often occurs during mining under unconsolidated aquifer, the biggest characteristic is abnormal mine pressure and support break-off during water inrush accident comparing with normal condition. In order to study mechanism of support break-off and water inrush during mining under the high confined thick unconsolidated aquifer, a simulation of similar material was designed. The experimental results indicated that, under normal condition, the compound breakage sequence of water-resisting key strata between coal seam and high confined thick unconsolidated aquifer is from top to bottom and the basic reason of synchronous fracture is the load of bottom key strata increased suddenly when the breakage of top key strata happened. Because of high confined thick unconsolidated aquifer, surface acts on the bottom key strata soil layer in the form of uniformly distributed load, which is the load-transfer mechanism of confined thick unconsolidated aquifer. Once the overlying key strata compound breaks, the height of unstable strata will reach far more than 30 meters and exceed support capability of current fully-mechanized mining supporter, which leads to support break-off accident during mining process under confined unconsolidated aquifer
DALNet: A Rail Detection Network Based on Dynamic Anchor Line
Rail detection is one of the key factors for intelligent train. In the paper,
motivated by the anchor line-based lane detection methods, we propose a rail
detection network called DALNet based on dynamic anchor line. Aiming to solve
the problem that the predefined anchor line is image agnostic, we design a
novel dynamic anchor line mechanism. It utilizes a dynamic anchor line
generator to dynamically generate an appropriate anchor line for each rail
instance based on the position and shape of the rails in the input image. These
dynamically generated anchor lines can be considered as better position
references to accurately localize the rails than the predefined anchor lines.
In addition, we present a challenging urban rail detection dataset DL-Rail with
high-quality annotations and scenario diversity. DL-Rail contains 7000 pairs of
images and annotations along with scene tags, and it is expected to encourage
the development of rail detection. We extensively compare DALNet with many
competitive lane methods. The results show that our DALNet achieves
state-of-the-art performance on our DL-Rail rail detection dataset and the
popular Tusimple and LLAMAS lane detection benchmarks. The code will be
released at https://github.com/Yzichen/mmLaneDet
A Wasserstein distributionally robust planning model for renewable sources and energy storage systems under multiple uncertainties
Nowadays, electricity markets and carbon trading mechanisms can promote investment in renewable sources but also generate new uncertainties in decision-making. In this paper, a two-stage Wasserstein distributionally robust optimization (WDRO) model is presented to determine the optimal planning strategy for renewable energy generators (REGs) and energy storage systems (ESSs) in the distribution network. This model considers supply-side and demand-side uncertainties in the distribution network and the interaction uncertainty from the main grid which are depicted by the ambiguity sets based on the Wasserstein metric and historical data. Meanwhile, both 1-norm and -norm Wasserstein metric constraints are considered to satisfy the decision-makers different preference. Furthermore, to solve this WDRO model, a systematic solution method with a three-step process is developed. Numerical results from a modified IEEE 33-node system and a 130-node system in the real world demonstrate the advantages of the two-stage WDRO model and the effectiveness of the solution method.</p
Feasibility Study of Hybrid Inverse Planning with Transmission Beams and Single-energy Spread-out Bragg Peaks for Proton Flash Radiotherapy
Ultra-high dose rate (FLASH) proton planning with only transmission beams
(TBs) has limitations in normal tissue sparing. The single-energy spread-out
Bragg peaks (SESOBPs) of FLASH dose rate have been demonstrated feasible for
proton FLASH planning. A hybrid inverse optimization method was developed to
combine the TBs and SESOBPs (TB-SESOBP) for FLASH planning. The SESOBPs were
generated from spreading out the BPs by pre-designed general bar ridge filters
and placed at the central target by range shifters to obtain a uniform dose
within the target. The SESOBPs and TBs were fully sampled field-by-field
allowing automatic spot selection and weighting in the optimization process.
The TB-SESOBP plans were validated in comparison with the TB only (TB-only)
plans and the plans with the combination of TBs and BPs (TB-BP) regarding 3D
dose and dose rate distributions for five lung cases. Comparing to the TB-only
plans, the mean spinal cord D1.2cc drastically reduced 41%, the mean lung V7Gy
and V7.4Gy moderately reduced by up to 17% and the target dose homogeneity
slightly increased in the TB-SESOBP plans. Comparable dose homogeneity was
achieved in both TB-SESOBP and TB-BP plans. Besides, prominent improvements
were achieved in lung sparing for the cases of relatively large targets by the
TB-SESOBP plans comparing to the TB-BP plans. The targets were fully covered
with the FLASH dose rate in all the three plans. For the OARs, V40Gy/s = 100%
was achieved by the TB-only plans while V40Gy/s > 85% was obtained by the other
two plans. We have demonstrated that the hybrid TB-SESOBP planning was feasible
to achieve FLASH dose rate for proton therapy. The hybrid TB-SESOBP planning
has great potential in improving OAR sparing while maintaining high target dose
homogeneity, and can be potentially implemented for adaptive radiotherapy
Measurement of the time structure of FLASH beams using prompt gamma rays and secondary neutrons as surrogates
We aim to investigate the feasibility of online monitoring of irradiation
time (IRT) and scan time for FLASH radiotherapy using a pixelated semiconductor
detector. Measurements of the time structure of FLASH irradiations were
performed using fast, pixelated spectral detectors, AdvaPIX-TPX3 and
Minipix-TPX3. The latter has a fraction of its sensor coated with a neutron
sensitive material. With little or no dead time and an ability to resolve
events that are closely spaced in time (tens of ns), both detectors can
accurately determine IRTs as long as pile-ups are avoided. To avoid pile-ups,
we placed the detectors beyond the Bragg peak or at a large scattering angle.
We acquired prompt gamma rays and secondary neutrons and calculated IRTs based
on timestamps of the first (beam-on) and the last (beam-off) charged species.
We also measured scan times in x, y, and diagonal directions. We performed
these measurements for a single spot, a small animal field, a patient field,
and a ridge filter optimized field to demonstrate in vivo online monitoring of
IRT. All measurements were compared to vendor log files. Differences between
measurements and log files for a single spot, a small animal field, and a
patient field were within 1%, 0.3% and 1%, respectively. In vivo monitoring of
IRTs was accurate within 0.1% for AdvaPIX-TPX3 and within 6.1% for
Minipix-TPX3. The scan times in x, y, and diagonal directions were 4.0, 3.4,
and 4.0 ms, respectively. Overall, the AdvaPIX-TPX3 can measure FLASH IRTs
within 1% accuracy, indicating that prompt gamma rays are a good surrogate for
primary protons. The Minipix-TPX3 showed a higher discrepancy, suggesting a
need for further investigation. The scan times (3.4 \pm 0.05 ms) in the 60-mm
distance of y-direction were less than (4.0 \pm 0.06 ms) in the 24-mm distance
of x-direction, confirming the much faster scanning speed of the Y magnets than
that of X.Comment: 11 pages, 5 figure
Multi-channel quantum noise suppression and phase-sensitive modulation in a hybrid optical resonant cavity system
Quantum noise suppression and phase-sensitive modulation of continuously
variable in vacuum and squeezed fields in a hybrid resonant cavity system are
investigated theoretically. Multiple dark windows similar to electromagnetic
induction transparency (EIT) are observed in quantum noise fluctuation curve.
The effects of pumping light on both suppression of quantum noise and control
the widths of dark windows are carefully analyzed, and the saturation point of
pumping light for nonlinear crystal conversion is obtained. We find that the
noise suppression effect is strongly sensitive to the pumping light power. The
degree of noise suppression can be up to 13.9 dB when the pumping light power
is 6.5 Beta_th. Moreover, a phase-sensitive modulation scheme is demonstrated,
which well fills the gap that multi-channel quantum noise suppression is
difficult to realize at the quadrature amplitude of squeezed field. Our result
is meaningful for various applications in precise measurement physics, quantum
information processing and quantum communications of system-on-a-chip
Clinical features and “early” corticosteroid treatment outcome of pediatric mycoplasma pneumoniae pneumonia
BackgroundMany children with mycoplasma pneumoniae (MP) pneumonia (MPP) developed sequelae such as bronchiolitis/bronchitis obliterans (BO). Early corticosteroid therapy might prevent disease progression. This study aimed to use “early” corticosteroid and observe the treatment outcome in patients with MPP.MethodsPatients who had pulmonary infiltrations on chest imaging within 5 days of the disease course and were suspected of having MP infection on admission were enrolled. Among them, patients whose disease course was within 10 days on admission were ultimately enrolled. We analyzed their data including the clinical features, the starting time and dose of corticosteroid therapy, and the treatment outcome. According to chest imaging, we divided patients into two groups (Group A: bronchiolitis-associated lesions or ground-glass opacities; Group B: pulmonary segmental/lobar consolidation).ResultsA total of 210 patients with confirmed MPP were ultimately enrolled. There were 59 patients in Group A and 151 patients in Group B. Patients in Group A were more prone to have allergy histories, hypoxemia, wheezing sound, and wet rales on auscultation than those in Group B. Corticosteroid treatment was initiated between 5 and 10 days of disease onset in all patients and 6–7 days in most patients. Methylprednisolone was prescribed in all patients within 10 days of disease onset, and the highest prescribed dose was at least 2 mg/kg/day. In Group A, methylprednisolone >2 mg/kg/day was prescribed in 22 patients, and among them, 8 patients with diffuse bronchiolitis-associated lesions received high-dose methylprednisolone therapy. After 3 months, lung CT revealed slightly segmental ground-glass opacity in three patients. In Group B, methylprednisolone >2 mg/kg/day was prescribed in 76 patients, and among them, 20 patients with pulmonary lobar consolidation received high-dose methylprednisolone therapy. After 3 months, chest imaging revealed incomplete absorption of pulmonary lesions in seven patients. Among them, five patients with consolidation in more than one pulmonary lobe ultimately had slight BO.ConclusionIn hospitalized patients with MPP, particularly severe MPP, the ideal starting time of corticosteroid treatment might be 5–10 days, preferably 6–7 days, after disease onset. The initial dosage of corticosteroid therapy should be decided according to the severity of the disease. MPP patients with diffuse bronchiolitis-associated lesions/whole lobar consolidation on imaging might require high-dose corticosteroid therapy
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