50 research outputs found
Improving SLI Performance in Optically Challenging Environments
The construction of 3D models of real-world scenes using non-contact methods is an important problem in computer vision. Some of the more successful methods belong to a class of techniques called structured light illumination (SLI). While SLI methods are generally very successful, there are cases where their performance is poor. Examples include scenes with a high dynamic range in albedo or scenes with strong interreflections. These scenes are referred to as optically challenging environments.
The work in this dissertation is aimed at improving SLI performance in optically challenging environments. A new method of high dynamic range imaging (HDRI) based on pixel-by-pixel Kalman filtering is developed. Using objective metrics, it is show to achieve as much as a 9.4 dB improvement in signal-to-noise ratio and as much as a 29% improvement in radiometric accuracy over a classic method. Quality checks are developed to detect and quantify multipath interference and other quality defects using phase measuring profilometry (PMP). Techniques are established to improve SLI performance in the presence of strong interreflections. Approaches in compressed sensing are applied to SLI, and interreflections in a scene are modeled using SLI. Several different applications of this research are also discussed
IT and Productivity in Developed and Developing Countries
Previous research at the cross-national level has found that IT investment is associated with significant productivity gains for developed countries but not for developing countries. Notwithstanding the lack of evidence of productivity gains, developing countries have increased their investment in IT dramatically. Given all of this investment, there is a need for research to study whether the investment has begun to pay off in greater productivity for developing countries. In this study, we employ production function analysis on new data on IT investment and productivity for 49 countries from 1985-2004, and compare the results from 1994-2004 with the earlier years (1985-1993) that were covered by Dewan and Kraemer (2000). The goal is to find out whether developing countries have been able to achieve significant productivity gains from IT investment in the more recent period as they have increased their IT capital stocks and gained experience with the use of IT. We also incorporate a set of complementary factors missing from previous studies, including telecommunications investment and prices, human resources, and foreign direct investment, to determine whether these factors have an impact on the relationship of IT to productivity. We find that for developing countries, there was no significant effect for IT capital for the 1985-1993 sample, but the relationship is positive and significant for the 1994-2004 sample. On the other hand, for developed countries, IT capital is significant across all time periods. Non-IT capital stock and labor hours also are positive and significant across all samples and time periods as expected. We also find developing countries with higher levels of tertiary education and lower telecommunication prices achieve greater productivity gains. To our knowledge, this is the first empirical research to find productivity impacts from IT investments in developing countries. The finding that developing countries only began to realize payoffs from IT investment in more recent years suggests that there may be some critical level of IT capital stock, or some minimum level of accumulated experience (human capital) required before such gains become evident. For policymakers in developing countries, these findings provide evidence that IT investments are likely to lead to productivity gains and give support for policies to promote IT investment and use
It diffusion in developing countries
here is widespread belief among international agencies and development specialists in the potential value of information technology (IT) to sup-port economic and human development [11, 12]. Some question whether IT alone can have a major impact on the standard of living in developing countries, but most see it offering access to vital information and services such as weather forecasting, commodity prices, health care, and education. However, a significant digital divide exists between richer and poorer countries in the use of IT and the availability of complementary assets such as telecommunications networks and skilled IT profes-sionals. This gap has led to a public debate about what can be done to promote greater IT use so that developing coun-tries can achieve the types of benefits already being enjoyed in the industrialized world. Policymakers need to recognize that developing economies have different drivers for IT investment than their wealthier brethren
Implementation of Solar Car Technology
Under the leadership of Dr. Erik Mayer, Pittsburg State University hosted the first Kansas Solar Race Competition. The purpose of this competition is to motivate students to learn about different aspects of solar car technology. The competition motivates students by bringing multiple teams together in a friendly competition to test out their uniquely engineered and constructed wireless cars. The cars will compete in different competitions such as an agility competition and a drag race. After the competition, the students are able to learn from the ingenuity of other teams and spark a curiosity to continue to learn about solar car technology for the next year
Natural History of Very Early Onset Inflammatory Bowel Disease in North America: A Retrospective Cohort Study
Background: The incidence of very early onset inflammatory bowel disease (VEOIBD) is increasing, yet the phenotype and natural history of VEOIBD are not well described. Methods: We performed a retrospective cohort study of patients diagnosed with VEOIBD (6 years of age and younger) between 2008 and 2013 at 25 North American centers. Eligible patients at each center were randomly selected for chart review. We abstracted data at diagnosis and at 1, 3, and 5 years after diagnosis. We compared the clinical features and outcomes with VEOIBD diagnosed younger than 3 years of age with children diagnosed with VEOIBD at age 3 to 6 years. Results: The study population included 269 children (105 [39%] Crohn\u27s disease, 106 [39%] ulcerative colitis, and 58 [22%] IBD unclassified). The median age of diagnosis was 4.2 years (interquartile range 2.9-5.2). Most (94%) Crohn\u27s disease patients had inflammatory disease behavior (B1). Isolated colitis (L2) was the most common disease location (70% of children diagnosed younger than 3 years vs 43% of children diagnosed 3 years and older; P = 0.10). By the end of follow-up, stricturing/penetrating occurred in 7 (6.6%) children. The risk of any bowel surgery in Crohn\u27s disease was 3% by 1 year, 12% by 3 years, and 15% by 5 years and did not differ by age at diagnosis. Most ulcerative colitis patients had pancolitis (57% of children diagnosed younger than 3 years vs 45% of children diagnosed 3 years and older; P = 0.18). The risk of colectomy in ulcerative colitis/IBD unclassified was 0% by 1 year, 3% by 3 years, and 14% by 5 years and did not differ by age of diagnosis. Conclusions: Very early onset inflammatory bowel disease has a distinct phenotype with predominantly colonic involvement and infrequent stricturing/penetrating disease. The cumulative risk of bowel surgery in children with VEOIBD was approximately 14%-15% by 5 years. These data can be used to provide anticipatory guidance in this emerging patient population
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Desalination utilizing clathrate hydrates (LDRD final report).
Advances are reported in several aspects of clathrate hydrate desalination fundamentals necessary to develop an economical means to produce municipal quantities of potable water from seawater or brackish feedstock. These aspects include the following, (1) advances in defining the most promising systems design based on new types of hydrate guest molecules, (2) selection of optimal multi-phase reactors and separation arrangements, and, (3) applicability of an inert heat exchange fluid to moderate hydrate growth, control the morphology of the solid hydrate material formed, and facilitate separation of hydrate solids from concentrated brine. The rate of R141b hydrate formation was determined and found to depend only on the degree of supercooling. The rate of R141b hydrate formation in the presence of a heat exchange fluid depended on the degree of supercooling according to the same rate equation as pure R141b with secondary dependence on salinity. Experiments demonstrated that a perfluorocarbon heat exchange fluid assisted separation of R141b hydrates from brine. Preliminary experiments using the guest species, difluoromethane, showed that hydrate formation rates were substantial at temperatures up to at least 12 C and demonstrated partial separation of water from brine. We present a detailed molecular picture of the structure and dynamics of R141b guest molecules within water cages, obtained from ab initio calculations, molecular dynamics simulations, and Raman spectroscopy. Density functional theory calculations were used to provide an energetic and molecular orbital description of R141b stability in both large and small cages in a structure II hydrate. Additionally, the hydrate of an isomer, 1,2-dichloro-1-fluoroethane, does not form at ambient conditions because of extensive overlap of electron density between guest and host. Classical molecular dynamics simulations and laboratory trials support the results for the isomer hydrate. Molecular dynamics simulations show that R141b hydrate is stable at temperatures up to 265K, while the isomer hydrate is only stable up to 150K. Despite hydrogen bonding between guest and host, R141b molecules rotated freely within the water cage. The Raman spectrum of R141b in both the pure and hydrate phases was also compared with vibrational analysis from both computational methods. In particular, the frequency of the C-Cl stretch mode (585 cm{sup -1}) undergoes a shift to higher frequency in the hydrate phase. Raman spectra also indicate that this peak undergoes splitting and intensity variation as the temperature is decreased from 4 C to -4 C
Another Shipment of Six Short-Period Giant Planets from TESS
We present the discovery and characterization of six short-period, transiting
giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS) --
TOI-1811 (TIC 376524552), TOI-2025 (TIC 394050135), TOI-2145 (TIC 88992642),
TOI-2152 (TIC 395393265), TOI-2154 (TIC 428787891), & TOI-2497 (TIC 97568467).
All six planets orbit bright host stars (8.9 <G< 11.8, 7.7 <K< 10.1). Using a
combination of time-series photometric and spectroscopic follow-up observations
from the TESS Follow-up Observing Program (TFOP) Working Group, we have
determined that the planets are Jovian-sized (R = 1.00-1.45 R),
have masses ranging from 0.92 to 5.35 M, and orbit F, G, and K stars
(4753 T 7360 K). We detect a significant orbital eccentricity
for the three longest-period systems in our sample: TOI-2025 b (P = 8.872 days,
= ), TOI-2145 b (P = 10.261 days, =
), and TOI-2497 b (P = 10.656 days, =
). TOI-2145 b and TOI-2497 b both orbit subgiant host
stars (3.8 g 4.0), but these planets show no sign of inflation
despite very high levels of irradiation. The lack of inflation may be explained
by the high mass of the planets; M (TOI-2145
b) and M (TOI-2497 b). These six new discoveries
contribute to the larger community effort to use {\it TESS} to create a
magnitude-complete, self-consistent sample of giant planets with
well-determined parameters for future detailed studies.Comment: 20 Pages, 6 Figures, 8 Tables, Accepted by MNRA
Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial
Background:
Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke.
Methods:
We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515.
Findings:
Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group.
Interpretation:
In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes.
Funding:
GlaxoSmithKline