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Time offset monitoring of multiple Global Navigation Satellite Systems is important for compatibility and interoperability. Unlike conventional signal space approaches, such as single-point positioning (SPP) and precise point positioning, an approach based on the principle of single difference among systems, single-difference point positioning (SDPP), is proposed to omit the receiver clock parameter and reduce the influence of the common model errors during estimation. The proposed approach was validated on different datasets, and results shown that the estimated time offset among systems using SDPP has no significant difference with that using SPP. Moreover, SDPP retrieves the best time offset estimation when considering it as a random walk process, as it provides smooth estimation with low noise. Furthermore, considering constraints from station coordinates and tropospheric delay further improves time offset estimation. The time offset estimation over time remains within a reasonable range, exhibits some periodicity, and estimation from different stations is consistent if disregarding system biases. In addition, the estimated time offset can be used to improve the SPP accuracy.

Fast and effective methods are needed for sequencing of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome to track genetic mutations and to identify new and emerging variants during the ongoing pandemic. The objectives were to assess the performance of the SARS-CoV-2 AmpliSeq research panel and S5 plug-in analysis tools for whole-genome sequencing analysis of SARS-CoV-2 and to compare the results with those obtained with the MiSeq-based ARTIC analysis pipeline, using metrics such as depth, coverage, and concordance of single-nucleotide variant (SNV) calls. A total of 191 clinical specimens and a single cultured isolate were extracted and sequenced with AmpliSeq technology and analysis tools. Of the 191 clinical specimens, 83 (with threshold cycle [CT] values of 15.58 to 32.54) were also sequenced using an Illumina MiSeq-based method with the ARTIC analysis pipeline, for direct comparison. A total of 176 of the 191 clinical specimens sequenced on the S5XL system and prepared using the SARS-CoV-2 research panel had nearly complete coverage (>98%) of the viral genome, with an average depth of 5,031×. Similar coverage levels (>98%) were observed for 81/83 primary specimens that were sequenced with both methods tested. The sample with the lowest viral load (CT value of 32.54) achieved 89% coverage using the MiSeq method and failed to sequence with the AmpliSeq method. Consensus sequences produced by each method were identical for 81/82 samples in areas of equal coverage, with a single difference present in one sample. The AmpliSeq approach is as effective as the Illumina-based method using ARTIC v3 amplification for sequencing SARS-CoV-2 directly from patient specimens across a range of viral loads (CT values of 15.56 to 32.54 [median, 22.18]). The AmpliSeq workflow is very easily automated with the Ion Chef and S5 instruments and requires less training and experience with next-generation sequencing sample preparation than the Illumina workflow.

Microwave signals, for example, those from Global Navigation Satellite Systems (GNSS) and very long baseline interferometry, are affected by tropospheric turbulence in such a way that the random fluctuations of the atmospheric index of refraction correlate the phase measurements. These atmospheric correlations are an important error source in space geodetic techniques. For computational reasons, they are neglected in positioning applications, to the detriment of a trustworthy description of the precision, and rigorous test statistics. Fortunately, modelling such correlations is possible by combining concepts from electromagnetic wave propagation in a random medium and the Kolmogorov turbulence theory. In this contribution, we will process single differences GNSS phase observations from a 300 m baseline between two different receivers linked to a common clock. After a preprocessing to filter additional error contributions, such as multipath, we will study the power spectral density of the phase residuals. We will estimate its low and high cutoff frequencies with an adapted unbiased Whittle maximum likelihood estimator. These cutoff frequencies – as predicted by turbulence theory – are related directly to the scale lengths of turbulence, i.e. the size of the eddies that correlate the GNSS observations. The study of their dependencies with the satellite geometry, day of the year, or time of the day provides new insights into the two- and three-dimensional atmospheric turbulence in the atmosphere. In addition, it contributes to improving the stochastic description of random effects impacting GNSS phase observations.

In this paper, a rank deficient adjustment model with inequality constrained is implemented to realise the conversion from the single-difference (SD) wide lane fractional cycle bias (WL-FCB) to und...

Professions such as radiology and aviation security screening that rely on visual search—the act of looking for targets among distractors—often cannot provide operators immediate feedback, which can create situations where performance may be largely driven by the searchers’ own expectations. For example, if searchers do not expect relatively hard-to-spot targets to be present in a given search, they may find easy-to-spot targets but systematically quit searching before finding more difficult ones. Without feedback, searchers can create self-fulfilling prophecies where they incorrectly reinforce initial biases (e.g., first assuming and then, perhaps wrongly, concluding hard-to-spot targets are rare). In the current study, two groups of searchers completed an identical visual search task but with just a single difference in their initial task instructions before the experiment started; those in the “high-expectation” condition were told that each trial could have one or two targets present (i.e., correctly implying no target-absent trials) and those in the “low-expectation” condition were told that each trial would have up to two targets (i.e., incorrectly implying there could be target-absent trials). Compared to the high-expectation group, the low-expectation group had a lower hit rate, lower false alarm rate and quit trials more quickly, consistent with a lower quitting threshold (i.e., performing less exhaustive searches) and a potentially higher target-present decision criterion. The expectation effect was present from the start and remained across the experiment—despite exposure to the same true distribution of targets, the groups’ performances remained divergent, primarily driven by the different subjective experiences caused by each groups’ self-fulfilling prophecies. The effects were limited to the single-targets trials, which provides insights into the mechanisms affected by the initial expectations set by the instructions. In sum, initial expectations can have dramatic influences—searchers who do not expect to find a target, are less likely to find a target as they are more likely to quit searching earlier.

The U.S. National Geodetic Survey (NGS) has historically processed dual-frequency GPS observations in a double-differenced mode using the legacy software called the Program for the Adjustment of GPS Ephemerides (PAGES). As part of NGS’ modernization efforts, a new software suite named M-PAGES (i.e., Multi-GNSS PAGES) is being developed to replace PAGES. M-PAGES consists of a suite of C++ and Python libraries, programs, and scripts built to process observations from all GNSS constellations. The M-PAGES team has developed a single-difference baseline processing strategy that is suitable for multi-GNSS. This approach avoids the difficulty of forming double-differences across systems or frequencies, which may inhibit integer ambiguity resolution. The M-PAGES suite is expected to deploy to NGS’ Online Positioning User Service (OPUS) later this year. Here, we present the processing strategy being implemented along with a performance evaluation from sample baseline solutions obtained from data collected within the NOAA CORS Network.

Signals from the Global Navigation Satellite System (GNSS) travel through the whole atmosphere and encounter fluctuations of the index of refraction. The long-term variations of the tropospheric refractive index delay the signals, whereas its random variations correlate with the phase measurements. The power spectral density of microwave phase difference can be derived from physical considerations by combining results from the Kolmogorov theory and electromagnetic wave propagation. Four different dominant noise regimes are expected. Their cutoff frequencies can be estimated with the unbiased Whittle Maximum Likelihood estimator; They provide information about the scale lengths of turbulence which are directly linked with the size of the eddies or swirling motion present in the free atmosphere. Dependencies of these parameters with the satellite geometry or the time of the day pave the way for a better comprehension of how tropospheric turbulence acts as correlating GNSS phase observations. The result is less empirical modeling of GNSS phase correlations to improve the positioning results and avoid an overestimation of their precision. We use GPS single differences from 290 m distant antenna positions recorded during two days in 2013 in a common clock experiment at the Physikalisch Technische Bundesanstalt in Braunschweig Germany to explain our methodology, based on adequate filtering of the residuals to mitigate multipath effects.

Due to the influence of pseudo-range noise, traditional GNSS common view method is difficult to improve the accuracy of time-frequency transfer. GNSS carrier phase precise point positioning (PPP) time-frequency transfer has become a research hotspot because of its high accuracy. In this paper, a time-frequency transfer model of GNSS carrier phase single difference (SD) and Integer Single Difference (ISD) between any two ground stations is studied. In order to solve the problem that the SD ambiguity cannot be fixed due to the influence of the phase biases at the receivers, a method of SD ambiguity fixing is proposed, that is the SD ambiguity is fixed with the constraint of the fixed double difference ambiguity among several stations and satellites. Here taking four time-frequency links between pairs of ground stations, BRUX-OPMT (262.3km), BRUX-PTBB (454.6km), BRUX-WTZR (637.7km) and BRUX-CEBR (1331.6km) as examples, the multi-GNSS time-frequency transfer experiment of SD, ISD and PPP method is carried out. The results show that the SD and PPP time-frequency transfer accuracy is equivalent, the stability of ISD is improved compared with SD, and the difference RMS between epochs is less than 10 ps. High precision carrier phase SD, ISD and PPP technology can be applied to the study of determining the gravity potential based on time-frequency measurements. This study is supported by the National Natural Science Foundations of China (NSFC) under Grants 42030105, 41721003, 41804012, 41631072, 41874023, Space Station Project (2020)228, and the Natural Science Foundation of Hubei Province of China under Grant 2019CFB611.

Single-difference (SD) ambiguity resolution (AR) and track-to-track (T2T) AR are two typical AR methods in precise orbit determination (POD) for Low Earth Orbit (LEO) satellites, which could improve the accuracy of orbits greatly. In this study, SD AR and T2T AR methods are introduced and analyzed. The performance of these two methods is assessed by three months of GPS observations from the Gravity Recovery and Climate Experiment Follow On (GRACE-FO) twin satellites. Results show that T2T AR is highly dependent on the stability of receiver hardware delays, while SD AR requires Fractional Cycle Bias (FCB) or Integer Recovery Clock (IRC) products. We find that these two methods have comparable performance in Reduced Dynamic Precise Orbit Determination (RDPOD), while SD AR slightly outperforms T2T AR in Kinematic Precise Orbit Determination (KPOD). We also find that SD AR has a higher AR success rate than T2T AR. Therefore, we recommend SD AR as the top choice in LEO orbit determination, and T2T AR can be a good alternative when FCB or IRC products are not available.

Objectives: This study evaluates the bond strength and marginal adaptation of mineral trioxide aggregate (MTA) Repair HP and Biodentine used as apical plugs; MTA was used as reference material for comparison. Materials and Methods: A total of 30 single-rooted teeth with standardized, artificially created open apices were randomly divided into three groups (n = 10 per group), according to the material used to form 6-mm-thick apical plugs: group 1 (MTA Repair HP); group 2 (Biodentine); and group 3 (white MTA). Subsequently, the specimens were transversely sectioned to obtain 2 (cervical and apical) 2.5-mm-thick slices per root. Epoxy resin replicas were observed under a scanning electron microscope to measure the gap size at the material/dentin interface (the largest and smaller gaps were recorded for each replica). The bond strength of the investigated materials to dentin was determined using the push-out test. The variable bond strengths and gap sizes were evaluated independently at the apical and cervical root dentin slices. Data were analyzed using descriptive and analytic statistics. Results: The comparison between the groups regarding the variables' bond strengths and gap sizes showed no statistical difference (p > 0.05) except for a single difference in the smallest gap at the cervical root dentin slice, which was higher in group 3 than in group 1 (p < 0.05). Conclusions: The bond strength and marginal adaptation to root canal walls of MTA HP and Biodentine cement were comparable to white MTA.

IntroductionPallid breath-holding spells are common and dramatic forms of recurrent syncope in infancy. They are very stressful despite their harmless nature and sometimes require treatment.ObjectiveThe objective of this study was to evaluate the efficacy of belladonna in severe breath-holding spells.MethodsThis is a multicentric, retrospective series involving 84 children with severe pallid breath-holding spells. Inclusion criteria were >1 pallid breath-holding spell with loss of consciousness, paediatric cardiology evaluation, and follow-up >6 months. In total, 45 patients received belladonna and 39 patients did not receive treatment, according to physician preference.ResultsMean age was 11 months, ranging from 4 to 18 months, with 54% of males. Mean spell duration was 30 seconds (interquartile range 15, 60), and the frequency was four episodes per month (interquartile range 0.5, 6.5). Comparison of baseline characteristics between groups showed similar demographics, with the single difference in the severity of the spells, being more severe in the treated group. When comparing the treated and non-treated groups at 3 months, only two (5%) patients had a complete remission in the first group, whereas 20 (44%) had remission in the belladonna group (pConclusionsBelladonna is highly effective to alleviate severe breath-holding spells in young children, without any major adverse effects.

The aim of this study was to evaluate the inclusion of two commercial probiotics, a bacterial complex and a complex containing Bacillus subtilis in diets for Nile tilapia juveniles. The effects on growth performance, hematological parameters, glucose concentration, intestinal morphology and histomorphometry of hepatocytes’ nuclei were assessed. Ninety-six fish juveniles with mean initial weight of 4.87 ± 0.64 g and 6.50 ± 0.2 cm total length were randomly distributed in 12 tanks (18 L), with eight fish in each tank, during 53 days. The following treatments were designed: (C) control, (CB) feed containing the bacterial complex, and (BS) feed containing B. subtilis. No significant differences were found in relation to the growth performance of fish. In relation to the hematological parameters, a single difference was observed regarding the number of erythrocytes, with the fish treated with the diet containing the bacterial complex displayed the highest values in relation to the C and BS groups, while the other parameters were not affected by the probiotic inclusions. Similarly, no differences were observed for the proximate composition of fish. The intestinal villi of fish fed the bacterial complex (CB) were higher and wider, but the thickness of the tunic was higher in B. subtilis. The histomorphometric variables of the hepatocytes’ nuclei of the fish from the CB treatment revealed higher values of area (μm²), perimeter (μm) and volume (μm3). It was concluded that there are no significant differences between the application of a bacterial complex or B. subtilis as probiotic additives for Nile tilapia juveniles.

Objective: To assess, during rapid maxillary expansion, the plaque index (PI) and the gingival index (GI) of patients with unilateral cleft lip and palate(UCLP) using Hyrax (HX) or inverted mini-Hyrax (IMHX) rapid maxillary expanders (RME) considering patients’ sex and age. Methods: PI (Quigley Index modified by Turesky et al) and GI (Löe and Silness) of 28 UCLP (11 females; 17 males: aged 8 to 15 years) submitted to daily RME activation were assessed before (T0) and 7 (T1), 28 (T2) and 90 (T3) days after activation. Log-linear models and Bonferroni correction were performed to analyze possible differences in PI and GI between RME, sexes or age groups over time. Results: Intra-group comparison revealed significant increases in PI of patients using HX (T0 < T2), IMHX (T0 < T3; T1< T3), males (T0 < T1; T0 < T2; T0 < T3) or aged 12-15 years (T0 < T1; T0 < T2; T0 < T3), and in GI of patients using IMHX (T0 < T3; T1 < T3), females (T1 < T3; T2 < T3) or aged 12-15 years (T0 < T3; T2 < T3). One inter-group difference in GI according to patients’ age (8-11 < 12-15; T1) was observed. Conclusions: Since a single difference between groups was encountered, the results of this study indicated that PI and GI during maxillary expansion were similar between HX and IMHX, sexes and the analyzed age groups. Therefore, orthodontists can use these RME in UCLP patients according to the patient’s necessity or their preferences. RESUMO Objetivo: avaliar, durante a expansão rápida da maxila (ERM), o índice de placa dentária (IP) e o índice gengival (IG) de pacientes com fissura labiopalatina unilateral (FLPU), usando o aparelho disjuntor Hyrax (HX) ou o mini-Hyrax invertido (MHXI), considerando-se também o sexo e a idade. Métodos: o IP (Quigley-Hein modificado por Turesky et al.) e o IG (Silness e Löe) de 28 pacientes com FLPU (11 meninas; 8-15 anos de idade) tratados com ativação diária do aparelho de ERM foram avaliados antes (T0) e após 7 (T1), 28 (T2) e 90 (T3) dias da ativação inicial. Modelos de regressão log-linear e correção de Bonferroni foram usados para analisar as possíveis diferenças de IP e IG entre os grupos, de acordo com o tipo de aparelho de ERM, sexo e idade, ao longo do tempo. Resultados: as comparações intragrupos revelaram aumentos significativos do IP em pacientes usando HX (T0< T2) ou MHXI (T0< T3; T1< T3), com idades entre 12 e 15 anos (T0 < T1; T0 < T2; T0 < T3), e do IG de pacientes usando MHXI (T0< T3; T1< T3), que eram meninas (T1 < T3; T2 < T3), com idades entre 12 e 15 anos (T0 < T3; T2 < T3). Uma diferença no IG entre grupos foi observada em relação à idade dos pacientes (8-11 < 12-15; T1). Conclusões: uma única diferença entre grupos foi encontrada, o que sugere que os resultados de IP e IG, durante a expansão maxilar, foram semelhantes entre os grupos HX e MHXI, bem como entre os sexos e idades analisadas. Dessa forma, os ortodontistas podem usar esses aparelhos de ERM no tratamento de pacientes com FLPU de acordo com as necessidades do paciente ou suas preferências.

IntroductionElectronic health records have been widely introduced into clinical practice. The aim of this study was to determine whether a small interface change could improve compliance with a key quality indicator, namely antenatal pertussis vaccination.MethodsAudits were performed between 1–31 July 2015 and 1–31 July 2017 of all deliveries at the Centenary Hospital for Women and Children to determine compliance with antenatal pertussis vaccination. The single difference between time points was changing the interface so the antenatal pertussis vaccination field became compulsory.Results275 and 299 women delivered in the audit periods. Vaccination rates almost doubled (52.7% vs 91.4%, pConclusionSmall interface changes increase compliance. Interface change could be considered for key quality outcomes in patient care.

Research Areas: Agriculture Aiticle in International Journal ABSTRACT - Recently, immunocastration with Improvac (ImmC). has been tested in broilers and a considerable reduction in serum testosterone concentration (reduced by 79% compared to roosters) was observed. The aim of this study was to evaluate the effect of immunocastration on meat fatty acid (FA) composition and its comparison with caponized and intact males (roosters). The study was conducted with 3 experimental groups: control group (roosters), the group of birds submitted to surgical caponization (SurgC), and the group of birds submitted to immunocastration with Improvac. The comparison of breast meat partial FA sums of castrated (SurgC and ImmC) with control birds (roosters) revealed that castrated birds showed significantly higher content of n-3 polyunsaturated fatty acids (n-3 PUFA) than control birds (1.76 vs. 1.46 g/100 g of total FA; superiority of 20.2%), which has contributed to the occurrence of significant differences on both the n-6/n-3 ratio and the atherogenicity index (AI). In contrast, on leg meat portion, castrated birds displayed higher contents of both total saturated and monounsaturated fatty acids (SFA and MUFA, with 2.2 and 4.1% more, respectively) and lower total n-6 PUFA content (8.3% less) than was observed in control birds, which contributed to significant differences in the AI index. On the other hand, the comparison of breast meat portion from SurgC with ImmC showed that immunocastration contributed to lower total SFA and higher total n-6 PUFA, which have contributed to significant differences on both Polyunsaturated/Saturated (P/S) and n-6/n-3 ratios. Whereas, on leg meat portion no significant differences were observed on partial sums and a single difference was observed on the thrombogenicity index. Immunocastration of broilers has contributed to minor changes in the FA profile, but has improved the overall lipid quality indexes in both breast and leg meat portions. Therefore, immunocastration could be applied as an alternative method to caponization without negative consequences in meat FA profile. info:eu-repo/semantics/publishedVersion

GNSS-based attitude determination technique is an important field of study, in which two schemes can be used to construct the actual system: the common clock scheme and the non-common clock scheme. Compared with the non-common clock scheme, the common clock scheme can strongly improve both the reliability and the accuracy. However, in order to gain these advantages, specific care must be taken in the implementation. The cares are thus discussed, based on the generating technique of carrier phase measurement in GNSS receivers. A qualitative assessment of potential phase bias contributes is also carried out. Possible technical difficulties are pointed out for the development of single-board multi-antenna GNSS attitude systems with a common clock.

Recently, ChaCha20 (the stream cipher ChaCha with 20 rounds) is in the process of being a standardized and thus it attracts serious interest in cryptanalysis. The most significant effort to analyse Salsa and ChaCha was explained by Aumasson et?al. long back (FSE 2008) and further, only minor improvements could be achieved. In this paper, first we revisit the work of Aumasson et?al. to provide a clearer insight of the existing attack (2248 complexity for ChaCha7, i.e.,?7 rounds) and show certain improvements (complexity around 2243) by exploiting additional Probabilistic Neutral Bits. More importantly, we describe a novel idea that explores proper choice of IVs corresponding to the keys, for which the complexity can be improved further (2239). The choice of IVs corresponding to the keys is the prime observation of this work. We systematically show how a single difference propagates after one round and how the differences can be reduced with proper choices of IVs. For Salsa too (Salsa20/8, i.e.,?8 rounds), we get improvement in complexity, reducing it to 2 245.5 from 2 247.2 reported by Aumasson et?al.

GNSS-R is a new technology for monitoring the water level with high efficiency. Compared with conventional water level measurement technique, such as satellite altimetry and tide gauges, GNSS-R can observe more reflected points with high temporal and spatial resolution and unaffected by the influence of the plate vertical motion. This paper presented an improved cGNSS-R altimetry algorithm based on single difference to derive the reflector heights epoch-by-epoch, which can enhance the temporal and spatial resolution of surface height measurements, furthermore, the other algorithm based on the double differenced carrier phase measurements was also presented in this paper. By using the observed data of cGNSS-R altimetry experiment conducted on Qinghe bridge of East Lake, Wuhan, the reflector heights between the reflected antenna and the lake surface were given to prove the above mentioned algorithms, and the precision were ±2~±4 cm. The results show that the proposed algorithms based on single and double difference which are used for water level retrieval can sufficiently decrease the influences due to clock error, ionospheric and tropospheric error.

By calibrating the inter-system bias (ISB), an inter-system model can be achieved to improve the performance of multi-global navigation satellite system (GNSS) positioning. A number of studies were carried out to compose inter-system models among code division multiple access (CDMA) systems. However, due to the frequency division multiple access (FDMA) technique, GLONASS phase and code observations suffer from inter-frequency phase bias (IFPB) and inter-frequency code bias (IFCB) respectively, which make it difficult to obtain the ISB among GLONASS and CDMA systems. In addition, most of the current inter-system models are unable to handle mixed frequencies. A new single difference-based uniform inter-system model suitable for all of the CDMA and FDMA frequency combinations is proposed in this study. We first utilize a particle filter approach to extract the IFPB rate. Afterwards, the multi-ISB parameters can be estimated by the proposed model simultaneously. Four short baselines containing the signals of GLONASS, GPS, BDS3, BDS2, Galileo, and QZSS are selected to validate the model. The quantitative results indicate that the IFPB rate can be extracted precisely by a particle filter within ten epochs. The inter-system phase bias valuations are sufficiently stable on a daily scale and have standard deviation near 0.01 cycles. After de-weighting the GLONASS code observations to reduce the influence of IFCB, the inter-system code bias is also stable. Furthermore, imposing the stable ISB on the multi-GNSS inter-system model can effectively improve the single-frequency real-time kinematic positioning accuracy and reliability for severely obstructed situations with only a small number of satellites observed.

In 2017, Xi’an city has released the latest standard of car-fuel and motor vehicle submission, at the same time, Xi’an city has issued traffic restriction of 2017. But after 2015, the air quality of Xi’an city has aggravated. This paper will conduct empirical research through single difference of 2016-2017 era. The result shows that mixed policies dimension aggravating the concentration of NO2 and PM2.5 decreases, but still remarkably aggravate it at 1% significance level. This result further manifests that policy has some effects, but can’t work out ideally.

We compared the characteristics of a Korean adult population diagnosed with diabetes using only a fasting plasma glucose criterion or an HbA1c criterion. The single difference between these two groups was age. Further studies should be undertaken to clarify whether age-specific diagnostic criteria would be appropriate in Korean populations.

The high-precision measurement of attitude information is of great significance to the satellites, aircraft and vehicle. How to measure the three-dimensional attitude of the carrier efficiently and accurately becomes the hotspot in the related research field. This paper proposes a new GNSS 3D attitude measurement system based on dual-antenna receiver with common clock. This system uses single-difference model to get real-time settlement of the carrier high-precision attitude information. When the baseline of the system is 1m in static environment, the baseline measurement accuracy is 2 mm, the yaw accuracy is 0.08 degrees, the pitch accuracy is 0.15 degrees and the roll accuracy is 0.14 degrees. When the baseline of the system is 0.5m in dynamic environment, the yaw accuracy is 0.4526 degrees, the pitch accuracy is 0.4801 degrees and the roll accuracy is 0.4353 degrees. The experimental results show that the system has good performance in terms of stability and applicability. It can be used in multi-system combining attitude measurement in the future, which has a strong practical application value and broad prospects.

With multi-antenna synchronized global navigation satellite system (GNSS) receivers, the single difference (SD) between two antennas is able to eliminate both satellite and receiver clock error, thus it becomes necessary to reconsider the equivalency problem between the SD and double difference (DD) models. In this paper, we quantitatively compared the formal uncertainties and dispersions between multiple SD models and the DD model, and also carried out static and kinematic short baseline experiments. The theoretical and experimental results show that under a non-common clock scheme the SD and DD model are equivalent. Under a common clock scheme, if we estimate stochastic uncalibrated phase delay (UPD) parameters every epoch, this SD model is still equivalent to the DD model, but if we estimate only one UPD parameter for all epochs or take it as a known constant, the SD (here called SD2) and DD models are no longer equivalent. For the vertical component of baseline solutions, the formal uncertainties of the SD2 model are two times smaller than those of the DD model, and the dispersions of the SD2 model are even more than twice smaller than those of the DD model. In addition, to obtain baseline solutions, the SD2 model requires a minimum of three satellites, while the DD model requires a minimum of four satellites, which makes the SD2 more advantageous in attitude determination under sheltered environments.

Salient detection approaches mainly use single local cues or global cues as its inputs features to detect salient objects, which are sensitive to complex background, so the effect of detection were not satisfactory. In this paper, we investigate the traits of saliency detection and observed the two following facts: Firstly, high-level saliency cues achieve better saliency detection results than low-level saliency cues. Secondly, multi-difference cues achieve better saliency detection results than single difference cues. Based on deeply analysis, we proposed an image saliency detection algorithm through high level multi-difference cues (HMDS). By using multi-difference, not only HMDS could remove the non-salient region effectively, but also it could enhance the pixel value of salient region at the same time. In order to evaluate the performance of HMDS, the proposed method is compared with seven state-of-the-art algorithms on five popular datasets. The final experimental results show that the proposed method performs effectiveness, and will have a perfect application prospect.

In a 1966 Playboy interview, Truman Capote said that In Cold Blood “would be precisely like a novel, with a single difference: every word of it would be true from beginning to end” (qtd. in De Bell...

In this study the GPS Precipitable Water Vapor (PWV) was derived and evaluated by a radiosode measure during the winter intensive observation in Gangneung site from January 5 till February 29 in 2012. Bernise 5.0 software was used to derive the GPS data. GPS-derived PWV from Zero difference (GANG) and Single difference (GANG and DAEJ) was high variance in time and about 5 times the PWV of radiosonde. GPS post-processing has been performed from two additional IGS site (Xian Dao, Ibaraki-ken) in order to correct the absolute troposphere errors. As a result, the mean bias error (MBE) and root mean square error (RMSE) and correlation compared with radiosonde measure were 0.67 mm, 6.40 mm, and 0.93, respectively. In order to correct the relative troposphere errors from the altitudinal difference between the two GPS receivers, we calculated the GPS-derived PWV by adding the data of GPS that was installed in Gangneung-Wonju University near the Gangwon Regional Meteorological Administration. In the end, the improved result showed that MBE, RMSE and correlation in comparison with radiosonde measures were 0.61 mm, 5.79 mm, and 0.93, respectively.

La zeolita es un recurso mineral abundante en el Estado de Sonora, cuya calidad lo convierte en un importante factor corrector de los deteriorados suelos de cultivo del Estado. La agricultura sonorense en los últimos años ha perdido tierras de labor por la salinidad, debido a la escasez de agua y la necesidad de obtenerla cada vez de pozos más profundos lo que provoca su salinización.El presente trabajo aborda el uso de una zeolita natural modificada químicamente para ser empleada como mejorador del suelo mediante intercambio iónico. El método empleado es similar a los empleados a nivel mundial, con la sola diferencia de la especificidad química, mineralógica de esta zeolita natural de Sonora.

The implementation of precise point positioning ambiguity fixing depends on the products which can be used to recover the characteristics of ambiguity by the service side. When users need to implement single difference between satellite method and the decoupled clock method they have no way to achieve the products, so they must provide the products themselves hard, but when users need to implement the integer phase clock method they can use the wide-lane FCB and integer phase clock provided by CNES. Therefore, in this paper we put forward the algorithm of sequential ambiguity fixing with direct rounding and analyze the effects of ambiguity fixing kinematic PPP based on this method. First we analyze the principle of PPP ambiguity fixing based on the models, and then we introduce the algorithm and how the users have to implement integer phase clock method. Last, based on the principle analysis we design the single-day and two-hour dynamic experiments, which are simulated by static data. Results of numerous stations show that: the algorithm of sequential ambiguity fixing with direct rounding can significantly improve the accuracy of positioning and the east shows more obvious effects, the improvement proportion of single-day and two-hour were approximately 30 and 60 %, so the result can verify the validity of the method proposed.

Based on the analysis of the GNSS navigation and positioning, this paper studies the key technology and superiority of the PPP based on single difference between satellites. The true observation data are used to compare and analyze the precision and convergence time of PPP based on GPS\GLONASS, GPS\BDS dual system, and GPS\GLONASS\BDS triple system. Finally, the conclusion is drawn as the following: GPS\GLONASS\BDS triple-system PPP technology has the optimal performance on positioning accuracy and convergence time. GPS\GLONASS dual-system PPP almost has the same performance with triple-system PPP. GPS\BDS has no impact on improving performance of GPS PPP, but can improve the performance of BDS PPP greatly.

Advanced sidereal filtering (ASF) is an observation-domain sidereal filtering that adopts the repeat time of each individual satellite separately rather than the mean repeat time, adopted by the modified sidereal filtering (MSF). To evaluate the performance of ASF, we apply the method to filter the multipath for a short baseline based on a dual-antenna Global Navigation Satellite System (GNSS) receiver. The errors from satellite and receiver clocks, satellite orbit, troposphere, ionosphere, and antenna phase center variations are greatly eliminated by single difference between the two antennas because they are connected to the same receiver clock. The performances of ASF are compared with MSF to evaluate the gain for multipath mitigation. Comparisons indicate that ASF slightly outperforms MSF when the repeat time values of all satellites incorporated in data processing are within the normal range (86,145&ndash, 86,165 s), but the difference of variance reduction rate between ASF and MSF is statistically significant. When the data of a satellite with repeat time outside the normal range are included, the performances of MSF become much worse, but ASF is almost not affected. This advantage of ASF over MSF is important because the proportion of the days on which at least one satellite&rsquo, s repeat time exceeds the normal range reaches 71.19% based on the statistics on the data of 2014 and 2015. After applying ASF multipath corrections on the test days, the averages of standard deviations of north, east, and up component are reduced from 3.8 to 2.1 mm, 3.2 to 1.7 mm, and 7.6 to 4.3 mm, respectively. Comparison between applying ASF with the single-day model and with the seven-day model indicates that the former is generally more effective in multipath reduction.

Here we consider the following functional equation, $$\Psi(X(x,\Psi(x)))=Y(x, \Psi(x)),$$ where X(x, y) and Y(x, y) are holomorphic functions in |x| < δ1, |y| < δ1. When we consider a nonlinear simultaneous system of two variables difference equations, we can reduce it to a single difference equation of first order by a solution Ψ of the above functional equation. We obtain a matrix by the linear terms of functions X and Y. When the all eigenvalues of the matrix are equal to 1, it is difficult to have a solution of the above functional equation. In the present paper, we derive a formal solution of the above functional equation under the condition. Further we prove the existence of a solution which is holomorphic and have an asymptotically expansion of the formal solution. Moreover, we will show an example of nonlinear difference system such that our results are applicable.

This study extends the stream of participative budgeting literature by introducing a new variable, Budgetary Participation Conflict (BPC). BPC occurs when the level of budget participation experienced by a manager differs from a desired level. We propose a model where BPC is the independent variable to further evaluate the effect of budget participation on job performance. Using path analysis, we measure the direct effect of BPC on job performance, and the indirect effects between BPC and performance that run through job satisfaction and job tenure in two countries, Mexico and the US. While the results do not indicate that BPC either directly or indirectly affects the performance of US managers, the results indicate that BPC negatively affects the job performance of Mexican managers indirectly through the effects of BPC on job satisfaction and job tenure. The relationship between tenure and performance is much stronger among the Mexican managers than among their US counterparts, which is the largest single difference between the Mexican and US results.

Various methods for precise orbit determination (POD) of low earth orbiters (LEO) are briefly introduced in this paper. Based on the software named SHORD-III developed by our institute, single-difference (SD) and zero-difference (ZD) dynamic POD based on LEO carrying an on-board GPS receiver is mainly discussed. The approaches are tested using real GRACE data (November 5–25, 2002) and independently validated with Satellite Laser Ranging (SLR) measurements over the same 21 days. Comparisons with the scientific orbits provided by GFZ indicate that the SD POD RMS accuracy can achieve 5, 10 and 6 cm in radial, along and cross the track, and the ZD POD RMS accuracy can achieve 4, 8 and 4 cm in radial, along and cross the track. SLR validation shows that SD POD accuracy is better than 8 cm in distance, and ZD POD accuracy is better than 6 cm.