REVISITING THE ROLE OF OBSERVATION SESSION DURATION ON PRECISE POINT POSITIONING ACCURACY USING GIPSY/OASIS II SOFTWARE

The accuracy of GPS precise point positioning (PPP) was previously modelled as a function of the observing session duration T. The NASA, JPL’s software GIPSY OASIS II (GOA-II) along with the legacy products was used to process the GPS data. The original accuracy model is not applicable anymore because JPL started releasing its products using new modelling and analysis strategies as of August 2007, and the legacy products are no longer available. The developments mainly comprise the new orbit and clock determination strategy, second order ionosphere modelling, and single station ambiguity resolution. Previously, the PPP accuracy was studied using v 4.0 of the GOA-II. The accuracy model showed coarser results compared to that of the relative positioning. Here, we processed the data of the International GNSS Service (IGS) stations to refine the accuracy of GOA-II PPP from version 6.3. Considering the above changes we refined the accuracy of PPP. First we modified the previous model used for the accuracy assessment. Then we tested out this model using straightforward polynomial and logarithmic models. The tests indicate the previous formulation still satisfactorily models the accuracy using refined coefficient values Sn = 7.8 mm, Se = 6.8 mm, Sv = 29.9 mm for T ≥ 2 h

A note on fractional Sumudu transform

We propose a new definition of a fractional-order Sumudu transform for fractional differentiable functions. In the development of the definition we use fractional analysis based on the modified Riemann-Liouville derivative that we name the fractional Sumudu transform. We also established a relationship between fractional Laplace and Sumudu duality with complex inversion formula for fractional Sumudu transform and apply new definition to solve fractional differential equations

On the solution of fractional Maxwell equations by Sumudu transform.

In this paper, we introduce the Maxwell equations of time- fractional order in lossy media. We derive the solution of these equations by using Sumudu transform techniques

The Drinfel'd Double and Twisting in Stringy Orbifold Theory

This paper exposes the fundamental role that the Drinfel'd double \dkg of the group ring of a finite group $G$ and its twists \dbkg, \beta \in Z^3(G,\uk) as defined by Dijkgraaf--Pasquier--Roche play in stringy orbifold theories and their twistings. The results pertain to three different aspects of the theory. First, we show that $G$--Frobenius algebras arising in global orbifold cohomology or K-theory are most naturally defined as elements in the braided category of \dkg--modules. Secondly, we obtain a geometric realization of the Drinfel'd double as the global orbifold $K$--theory of global quotient given by the inertia variety of a point with a $G$ action on the one hand and more stunningly a geometric realization of its representation ring in the braided category sense as the full $K$--theory of the stack $[pt/G]$. Finally, we show how one can use the co-cycles $\beta$ above to twist a) the global orbifold $K$--theory of the inertia of a global quotient and more importantly b) the stacky $K$--theory of a global quotient $[X/G]$. This corresponds to twistings with a special type of 2--gerbe.Comment: 35 pages, no figure

Oscillation of solutions of some generalized nonlinear α-difference equations

In this paper, the authors discuss the oscillation of solutions of some generalized nonlinear α-difference equation Δα(ℓ)(p(k)Δα(ℓ)u(k))+q(k)f(u(k−τ(k)))=0,(1) k∈[a,∞), where the functions p, q, f and τ are defined in their domain of definition and α>1, ℓ is a positive real. Further, uf(u)>0 for u≠0, p(k)>0 and limk→∞(k−τ(k))=∞, where Rk=∑[k−ℓℓ]r=01αrp(rℓ)→∞ as k→∞ and u(k) is defined for k≥mini≥0(i−τ(i)) for all k∈[a,∞) for some a∈[0,∞)

Realistic Mathematics Education in Indonesia and Recommendations for Future Implementation: A Meta-Analysis Study

This meta-analysis study aims to investigate the effectiveness of applying realistic mathematics education (RME) in Indonesia to students' mathematical abilities. This study analyzes 95 effect sizes from 72 studies that have been published in national and international journals or proceedings from 2010 to 2019. Comprehensive Meta-Analysis (CMA) software is used to aid analysis. As a result of the study, the overall effect size was 1.104, with a standard error of 0.065 according to the random-effects model. These results indicate that the average person who is ranked 13th in the experimental group is equivalent to those who are ranked 4th in the control group. This research was carried out by considering four characteristics, resulting in significant differences in terms of sample size and duration of treatment. Thus the application of RME in Indonesia is very effective in improving students' mathematical abilities by considering the sample size and duration of treatment

Static Calibration of Tactical Grade Inertial Measurement Units

The research that led to this report was partially supported by a contract from the Strategic Environmental Research and Development Program (SERDP), contract number, W912HQ-08-C- 0044.This report was also presented in partial fulfillment of the requirements for the Master of Science Degree to the Graduate School of the Ohio State University.The demand for precise positioning grows up parallel to the advances in production of the geolocation instruments. Today, the Global Positioning System (GPS) is the most common positioning system in use because of its being very precise, convenient and cheap. However, when working in such areas that the external references (e.g. GPS satellites) are not available, a system that does not require information from any external source of information is required. Especially, these kinds of systems necessitate in detection of unexploded ordnances (UXO) buried in forestry areas, where precise position information is vital for removing them. The Inertial Navigation System (INS) operates in any environment and does not depended on any external source of information. It can operate alone or as an integrated system with GPS. However, the Inertial Measurement Unit (IMU) sensor outputs include some errors which can cause very large positioning errors. These errors can significantly be reduced by using calibration methods. The most accurate calibration methods are performed in laboratories and they require very precise instruments. However, the most significant IMU errors, biases and scale factor errors, change from turn on to turn on of the IMU and therefore they need to be estimated before every mission. The Multi-Position Calibration Method developed by Shin (2002) is a good example which is cost efficient and it can be applied in the field without use of any external calibration instrument. The method requires numerous IMU attitude measurements and use the gravity magnitude and Earth rotation rate as reference for calibration. The performance of the Multi-Position Calibration Method was tested by using a cart based geolocation system which includes 2 tactical grade IMUs, Honeywell HG1700 and HG1900. The calibration test was conducted in a parking lot of Ohio State University on 06 June 2010. The calibration estimations have shown that the navigation accuracy could be improved by up to 19.8% for the HG1700 and 17.8% for the HG1900. However, the results were not consistent among each other and in some cases decrease in the positioning accuracy was yielded

Mushroom body-specific profiling of gene expression identifies regulators of long-term memory in Drosophila

Memory formation is achieved by genetically tightly controlled molecular pathways that result in a change of synaptic strength and synapse organization. While for short- term memory traces rapidly acting biochemical pathways are in place, the formation of long-lasting memories requires changes in the transcriptional program of a cell. Although many genes involved in learning and memory formation have been identified, little is known about the genetic mechanisms required for changing the transcriptional program during different phases of long-term memory formation. With Drosophila melanogaster as a model system we profiled transcriptomic changes in the mushroom body, a memory center in the fly brain, at distinct time intervals during long- term memory formation using the targeted DamID technique. We describe the gene expression profiles during these phases and tested 33 selected candidate genes for deficits in long-term memory formation using RNAi knockdown. We identified 10 genes that enhance or decrease memory when knocked-down in the mushroom body. For vajk-1 and hacd1, the two strongest hits, we gained further support for their crucial role in learning and forgetting. These findings show that profiling gene expression changes in specific cell-types harboring memory traces provides a powerful entry point to identify new genes involved in learning and memory. The presented transcriptomic data may further be used as resource to study genes acting at different memory phases

Magnetodielectric coupling of a polar organic-inorganic hybrid Cr(II) phosphonate

Cr[(H(3)N-(CH(2))(2)-PO(3))(Cl)(H(2)O)] represents a rare example of a polar organic-inorganic hybrid material that exhibits a canted antiferromagnetic order below T(N)=5.5 K. The unusual coexistence of a polar crystal structure and magnetic order triggered our investigation of the magnetodielectric coupling. The coupling is evidenced by an anomaly in the temperature dependence of the dielectric constant epsilon below the Neel temperature. The magnetocapacitance is enhanced by one order of magnitude below T(N). The main characteristics of the magnetodielectic response are interpreted by Landau theoretical coupling terms

The Genetics of Adverse Drug Outcomes in Type 2 Diabetes:A Systematic Review

Background: Adverse drug reactions (ADR) are a major clinical problem accounting for significant hospital admission rates, morbidity, mortality, and health care costs. One-third of people with diabetes experience at least one ADR. However, there is notable interindividual heterogeneity resulting in patient harm and unnecessary medical costs. Genomics is at the forefront of research to understand interindividual variability, and there are many genotype-drug response associations in diabetes with inconsistent findings. Here, we conducted a systematic review to comprehensively examine and synthesize the effect of genetic polymorphisms on the incidence of ADRs of oral glucose-lowering drugs in people with type 2 diabetes. Methods: A literature search was made to identify articles that included specific results of research on genetic polymorphism and adverse effects associated with oral glucose-lowering drugs. The electronic search was carried out on 3rd October 2020, through Cochrane Library, PubMed, and Web of Science using keywords and MeSH terms. Result: Eighteen articles consisting of 10, 383 subjects were included in this review. Carriers of reduced-function alleles of organic cation transporter 1 (OCT 1, encoded by SLC22A1) or reduced expression alleles of plasma membrane monoamine transporter (PMAT, encoded by SLC29A4) or serotonin transporter (SERT, encoded by SLC6A4) were associated with increased incidence of metformin-related gastrointestinal (GI) adverse effects. These effects were shown to exacerbate by concomitant treatment with gut transporter inhibiting drugs. The CYP2C9 alleles, (*)2 (rs1799853C>T) and (*)3 (rs1057910A>C) that are predictive of low enzyme activity were more common in subjects who experienced hypoglycemia after treatment with sulfonylureas. However, there was no significant association between sulfonylurea-related hypoglycemia and genetic variants in the ATP-binding cassette transporter sub-family C member 8 (ABCC8)/Potassium Inwardly Rectifying Channel Subfamily J Member 11 (KCNJ11). Compared to the wild type, the low enzyme activity C allele at CYP2C8(*)3 (rs1057910A>C) was associated with less weight gain whereas the C allele at rs6123045 in the NFATC2 gene was significantly associated with edema from rosiglitazone treatment. Conclusion: In spite of limited studies investigating genetics and ADR in diabetes, some convincing results are emerging. Genetic variants in genes encoding drug transporters and metabolizing enzymes are implicated in metformin-related GI adverse effects, and sulfonylurea-induced hypoglycemia, respectively. Further studies to investigate newer antidiabetic drugs such as DPP-4i, GLP-1RA, and SGLT2i are warranted. In addition, pharmacogenetic studies that account for race and ethnic differences are required