8 research outputs found
Ray Tracing Simulation in Nonspherically Symmetric Atmosphere for GPS Radio Occultation
A three-dimensional ray tracing model with aiming algorithms for global positioning system (GPS) signal is proposed to make simulations conform to the realistic radio occultation (RO) signal propagation. The two aiming algorithms used in this study ensure the initial and end point ray trajectories are located in the prescribed region. In past studies, the ray tracing techniques applied to the RO signal simulation usually assumed a spherically symmetrical atmosphere for simplicity. The exact GPS and low earth orbit (LEO) satellite locations are not considered in the simulation. These two assumptions make the simulation unrealistic for GPS signal propagation in the RO technique. In the proposed model, the shape of the earth is assumed as an ellipse. The information from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis is used to setup the atmosphere in the simulation. Two aiming algorithms are developed to determine the initial signal propagating direction to make the simulated signal start from the prescribed GPS satellite position and end in the close vicinity of the LEO satellite position. An ideal spherical symmetric atmospheric structure is used to verify the ray tracing model. The fractional difference between real and simulated refractivity results is less than 0.1%. Otherwise, the GPS and LEO satellite position in the Formosat-3/COSMIC observation and the ECMWF analysis, considering the earth¡¦s flattening, is also used to verify the aiming algorithms. All of the simulated signals end in close vicinity to the LEO satellite position in the simulation results
Electromagnetic Scattering From Rough Surfaces Covered with Short Branching Vegetation
http://deepblue.lib.umich.edu/bitstream/2027.42/21094/2/rl0961.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/21094/1/rl0961.0001.001.tx
Electromagnetic Scattering Interaction Between a Dielectric Cylinder and a Slightly Rough Surface
http://deepblue.lib.umich.edu/bitstream/2027.42/21104/2/rl0978.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/21104/1/rl0978.0001.001.tx
Electromagnetic Scattering from Short Branching Vegetation
http://deepblue.lib.umich.edu/bitstream/2027.42/21105/2/rl0980.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/21105/1/rl0980.0001.001.tx
The Academic Portfolio System (APS) Usage Intention of Senior High School Students in Taiwan
Taiwan began to implement a new high school syllabus nationwide, in 2019. The Ministry of Education has also established a high school student Academic Portfolio System (APS) to collect the learning process of high school students for future university admissions references. However, during this period, high school students and their parents had many opinions on the implementation of the new system. There were even groups of students protesting. The main purpose of this research is to explore the factors that affect the system usage intentions of high school students. Based on the theory of reasoned action (TRA) and the technology acceptance model (TAM), this research established a research model. The research variables include system interface design, usefulness, ease of use, attitude, subjective norms, and usage intentions. A total of 712 questionnaires were collected from high school students in northern Taiwan. Data analysis is carried out in three stages: descriptive analysis, measurement model verification, and structural equation modeling. The results of the study found that system interface design has a significant impact on the perceived ease of use. Factors such as ease of use, usefulness, attitude, and subjective norms also have a significant positive impact on usage intention; ease of use and usefulness positively affect attitudes toward using. Finally, according to the results, some practical implications were proposed for implementation references from the perspectives of education authority, high schools, teachers, and students
Secukinumab in psoriasis patients with prior ustekinumab treatment: Results of a single-center experience
Background/Objective: To date, no clinical trials have evaluated the therapeutic response among psoriasis patients switching from ustekinumab to secukinumab. The objective of this study was to report our experience of treating psoriasis patients with secukinumab therapy who had ever received ustekinumab previously.
Methods: We retrospectively reviewed the therapeutic responses of nine patients with moderate-to-severe psoriasis who attended the clinical trials of first ustekinumab and then secukinumab. Ustekinumab (45Â mg) was given at Weeks 0, 4, and 16, and patients were evaluated for safety and efficacy at Weeks 12 and 16. After the end of the ustekinumab treatment period, patients were treated as needed by other modalities. In 2011, eligible patients were recruited again in a Phase 3, double-blind, secukinumab trial (ERASURE). Secukinumab (150Â mg or 300Â mg) was given at Weeks 0, 1, 2, 3, and 4 and then every 4 weeks. A single evaluator performed all the assessments.
Results: Among the nine patients, five patients (55.6%) had at least 75% reduction in the Psoriasis Area Severity Index (PASI75) score response, and four patients (44.4%) had at least 90% reduction in the Psoriasis Area Severity Index (PASI90) score response at Week 12 during secukinumab therapy. Their prior experience during ustekinumab therapy revealed at least PASI75 response in four patients (44.4%) and at least PASI90 response also in four patients (44.4%) at Week 12. Mean absolute PASI change at Week 12 of secukinumab therapy in our patients was −17.47.
Conclusion: Biologic switch is effective and valuable. Patients who have ever responded to ustekinumab seem to have a better response to secukinumab
Association of Three Different Dietary Approaches to Stop Hypertension Diet Indices with Renal Function in Renal Transplant Recipients
Several dietary indices assess the impacts of the Dietary Approaches to Stop Hypertension (DASH) diet on health outcomes. We explored DASH adherence and renal function among 85 Taiwanese renal transplant recipients (RTRs) in a cross-sectional study. Data collection included demographics, routine laboratory data, and 3-day dietary records. Three separate DASH indices, that defined by Camões (based on nine nutrients), that defined by Fung (using seven food groups and sodium), and that modified by Fung (as above but separated for men and women) were used. Renal function was ascertained through the estimated glomerular filtration rate (eGFR) from patients’ medical records. Participants’ mean age was 49.7 ± 12.6 years and eGFR was 54.71 ± 21.48 mL/min/1.73 m2. The three established DASH diet indices displayed significant correlations (r = 0.50–0.91) and indicated the nutritional adequacy of the diet. Multiple linear regressions indicated a significant positive association between higher DASH scores for each index and increased eGFR. In addition, RTRs in the highest DASH score tertile had higher eGFR rates than those in the lowest tertile, regardless of confounding variables. Adherence to a DASH-style diet correlated with better renal function among RTRs. Educating RTRs about the DASH diet may prevent graft function deterioration