611 research outputs found
Study of Asymptotic Free Scalar Field Theories from Adaptive Perturbation Method
We focus on the behavior of (2+1)d and (5+1)d
or theories in different regimes and compare the results
obtained from the adaptive perturbation method with those obtained from lattice
simulation. These theories are simple models that exhibit asymptotic freedom,
which is a property that is also observed in more complex theories such as QCD,
which describes the strong interaction between quarks and gluons. Asymptotic
freedom is an important feature of these theories because it allows for a
perturbative treatment of interactions at high energies. However, the standard
perturbation scheme breaks down in the presence of strong interactions, and the
adaptive perturbation method, which involves resuming the Feynman diagrams, is
more suitable for studying these interactions. Our research involves comparing
the perturbation result to lattice simulation. In the case of the
theory, there is no stable vacuum, so we explore evidence from the
theory instead. Our results appear to show that resummation improves the strong
coupling result for both the and theories.
Additionally, we improve the resummation method for the three-point coupling
vertex and study the RG flow to analyze the resummation contribution and
theoretical properties.Comment: 14 pages, 6 figures, minor change
Explore the Origin of SSB from Adaptive Perturbation Method
Spontaneous symmetry breaking occurs when the underlying laws of a physical
system are symmetric, but the vacuum state chosen by the system is not. The
(3+1)d theory is relatively simple compared to other more complex
theories, making it a good starting point for investigating the origin of
non-trivial vacua. The adaptive perturbation method is a technique used to
handle strongly coupled systems. It has been successful in strongly coupled QM
and is being generalized to scalar field theory to analyze the system in the
strong-coupling regime. The unperturbed Hamiltonian does not commute with the
usual number operator. However, the quantized scalar field admits a plane-wave
expansion when acting on the vacuum. While quantizing the scalar field theory,
the field can be expanded into plane-wave modes, making the calculations more
tractable. However, the Lorentz symmetry, which describes how physical laws
remain the same under certain spacetime transformations, might not be manifest
in this approach. The proposed elegant resummation of Feynman diagrams aims to
restore the Lorentz symmetry in the calculations. The results obtained using
this method are compared with numerical solutions for specific values of the
coupling constant . Finally, we find evidence for
quantum triviality, where self-consistency of the theory in the UV requires
. This result implies that the theory alone does not
experience SSB, and the phase is protected under the
RG-flow by a boundary of Gaussian fixed-points.Comment: 14 pages, 6 figures, minor change
High-speed, low cost test platform using FPGA technology
The object of this research is to develop a low-cost, adaptable testing platform for multi-GHz digital applications, with concentration on the test requirement of advanced devices. Since most advanced ATEs are very expensive, this equipment is not always available for testing cost-sensitive devices. The approach is to use recently-introduced advanced FPGAs for the core logic of the testing platform, thereby allowing for a low-cost, low power-consumption, high-performance, and adaptable test system. Furthermore to customize the testing system for specific applications, we implemented multiple extension testing modules base on this platform. With these extension modules, new functions can be added easily and the test system can be upgraded with specific features required for other testing purposes. The applications of this platform can help those digital devices to be delivered into market with shorter time, lower cost and help the development of the whole industry.Ph.D
EFFECT OF ARCH SUPPORT FOOT ORTHOSIS ON LOWER WTREMIN LOADING AND KINEMATICS DURING THE REBOUND
The purpose of this study was to determine whether arch support foot orthosis was capable of altering lower extremity loading and kinematics during the rebound. Nineteen female Division I basketball players participated in this study. Utilizing a repeated measures design, participants completed two rebound tasks with and without the arch support foot orthosis. Results showed that the selected arch support foot orthosis significantly decreased the peak impact force, knee internal rotation and foot inversion angle at the initial contact of the ground compared to those of the flat insole. It suggested that the use of the arch support foot orthosis can decrease the lower extremity loading and further decrease the risk of ACL injury in female basketball players
THE INFLUENCE OF ARCH SUPPORT INSOLE ON BASKETBALL JUMP SHOT
The purpose of this investigation was to examine the effects of arch support insole on jump shot scored percentage and kinetics. Eleven females Division I basketball participated in this study. They performed the jump shots until 5 shots were scored in arch support insoles and flat insoles. Kinematic data were collected with a motion analysis system (Motion Analysis Corporation, Santa Rosa, CA, USA) at 200-Hz sampling rate. Kinetic data were collected with two AMTl force platforms (AMTI Inc., Watertown, MA, USA) at 2000-Hz sampling rate. Non-parametric Wilcoxon signed-rank test was used to compare differences between arch support insole and flat insole on variables. No difference was found on jump shot scored percentage, jump height, peak ground reaction force, time to peak force and rate of force development. Wearing arch supporting insole did not influence the jump shot scored percentage and kinetics during jump shot
The Design and Implementation of the Defender Cloud on TWAREN Backbone
Defender Cloud is a cloud based backbone network defending system having full scope over the whole backbone network. Rather than detecting suspicious network activities on a local area network, it collects and integrates the flow data from all connecting members and all entrances of a backbone network. After analyzing by a proposed cloud based distributed processing model, the corresponding defensive reaction can be carried out in a global basis. Thus its protection can cover the whole network, even including member institutions without their own firewall. This paper illustrates the design, verification and future perspective of the Defender Cloud, with an emphasis on the distributed processing of the flow data
Managing cardiac arrest with refractory ventricular fibrillation in the emergency department: Conventional cardiopulmonary resuscitation versus extracorporeal cardiopulmonary resuscitation
AbstractAimRefractory ventricular fibrillation, resistant to conventional cardiopulmonary resuscitation (CPR), is a life threatening rhythm encountered in the emergency department. Although previous reports suggest the use of extracorporeal CPR can improve the clinical outcomes in patients with prolonged cardiac arrest, the effectiveness of this novel strategy for refractory ventricular fibrillation is not known. We aimed to compare the clinical outcomes of patients with refractory ventricular fibrillation managed with conventional CPR or extracorporeal CPR in our institution.MethodThis is a retrospective chart review study from an emergency department in a tertiary referral medical center. We identified 209 patients presenting with cardiac arrest due to ventricular fibrillation between September 2011 and September 2013. Of these, 60 patients were enrolled with ventricular fibrillation refractory to resuscitation for more than 10min. The clinical outcome of patients with ventricular fibrillation received either conventional CPR, including defibrillation, chest compression, and resuscitative medication (C-CPR, n=40) or CPR plus extracorporeal CPR (E-CPR, n=20) were compared.ResultsThe overall survival rate was 35%, and 18.3% of patients were discharged with good neurological function. The mean duration of CPR was longer in the E-CPR group than in the C-CPR group (69.90±49.6min vs 34.3±17.7min, p=0.0001). Patients receiving E-CPR had significantly higher rates of sustained return of spontaneous circulation (95.0% vs 47.5%, p=0.0009), and good neurological function at discharge (40.0% vs 7.5%, p=0.0067). The survival rate in the E-CPR group was higher (50% vs 27.5%, p=0.1512) at discharge and (50% vs 20%, p=0. 0998) at 1 year after discharge.ConclusionsThe management of refractory ventricular fibrillation in the emergency department remains challenging, as evidenced by an overall survival rate of 35% in this study. Patients with refractory ventricular fibrillation receiving E-CPR had a trend toward higher survival rates and significantly improved neurological outcomes than those receiving C-CPR
Pregnancy-induced hypertension is an independent risk factor for meconium aspiration syndrome: A retrospective population based cohort study
Objective: Meconium aspiration syndrome (MAS), possibly resulting from fetal hypoxia, is a respiratory distress disorder in the infant. Pregnancy-induced hypertension (PIH) can cause placental dysfunction and lead to fetal hypoxia, which may induce the development of MAS. Therefore, the aim of this study was to determine the association between PIH and MAS and to identify the predictive risk factors. Materials and methods: This was a retrospective cohort study. We selected patients with newly diagnosed PIH and a matched cohort group from the Taiwan National Health Insurance Research Database (NHIRD), from January 1, 2000 till December 31, 2013. For each patient in the PIH cohort, 4 subjects without PIH, matched for age and year of delivery, were randomly selected as the comparison cohort. The incidence of meconium aspiration syndrome was assessed in both groups. Results: Among the 23.3 million individuals registered in the NHIRD, 29,013 patients with PIH and 116,052 matched controls were identified. Patients who experienced PIH had a higher incidence of MAS than did those without PIH. According to a multivariate analysis, PIH (odds ratio [OR] = 1.70, 95% confidence interval [CI] = 1.49–1.93, p < 0.0001) was independently associated with increased risk of MAS. Additionally, age ≥30 years (OR = 1.26, 95% CI = 1.12–1.42, p = 0.0001), nulliparity (OR = 1.13, 95% CI = 1.01–1.27, p = 0.0367) and patients with diabetes mellitus (OR = 3.09, 95% CI = 1.35–7.09, p = 0.0078) were also independent risk factors of MAS. Conclusion: Patients with PIH obtained higher subsequent risk for the development of MAS than those without PIH. Besides, age ≥30 years, nulliparity and patients with diabetes mellitus are the independent risk factors of developing MAS. Keywords: Pregnancy-induced hypertension, Hypertension in pregnancy, Gestational hypertension, Preeclampsia, Meconium aspiration syndrom
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