Unified Test Research Articles

Unified Testing and Security Framework for Wireless Network-on-Chip Enabled Multi-Core Chips

On-chip wireless interconnects have been demonstrated to improve the performance and energy consumption of data communication in Network-on-Chips (NoCs). However, the wireless interfaces (WIs) can be defective, rendering these broken links severely affect the performance. This makes manufacturing test of the WIs critical. While analog testing of the transceivers is possible, such methodologies are impractical in a Wireless NoC (WiNoC) due to large overheads. In addition to testing, security is another prominent challenge in WiNoCs, as the security breach can happen due to embedded hardware Trojans or through external attacker exploiting the wireless medium. The typical security measures used in general wireless networks are not practical in a WiNoC due to unique network architectures and performance requirements of such a system. However, both testing and security defense can potentially leverage a basic monitoring framework which, can detect malfunctions or anomalies. Based on this idea, we propose a unified architecture for testing and attack detection and protection of on-chip wireless interconnects. We adopt a Built-In-Self Test (BIST) methodology to enable online monitoring of the wireless interconnects which can also be reused for monitoring the security threats. We focus on manufacturing defects of the WIs for testing and persistent jamming attack for the security measures, as this kind of attack is most likely on wireless communication systems. The BIST methodology is capable of detecting faults in the wireless links with a low aliasing probability of 2.32× 10 −10 . Additionally, the proposed unified architecture is able to detect the persistent jamming with an accuracy of 99.87% and suffer < 3% communication bandwidth degradation even in the presence of attacks from either internal or external sources.

Fatigue and self-healing characterization of asphalt composites containing rock asphalts

Fatigue cracking is one of the major distresses that causes early pavement failures. One of the solutions to delay the occurrence of pavement failure by fatigue cracking is to use materials that not only can resist such cracking but also can heal them over time. This is therefore necessary to evaluate the impact of such materials on fatigue cracking resistance and self-healing properties of asphalt mixtures. The increasing use of alternative materials such as rock asphalts has made this need even more pronounced. Fittingly, this paper presents the findings from a study that utilizes a fracture test and a combined fatigue-healing test to evaluate the influence of different sources of rock asphalts-Buton, Qingchuan (QC) and Uintaite Modifier (UM) on the fatigue and self-healing properties of fine aggregate matrix (FAM) mixture. The fracture test results indicate that rock asphalt can effectively improve the cracking resistance of asphalt mortars or FAM. The viscoelastic continuum damage (VECD) analyses of the combined fatigue-healing test results show that rock asphalt can significantly enhance the fatigue cracking resistance of FAM mixture. The results also show that, at same volume concentration of binder, UM rock asphalt and QC rock asphalt enhance fatigue cracking resistance of FAM very similarly but much better than does the Buton rock asphalt. An increase in the concentration of Buton rock asphalt made the FAM mixture even more resistant to fatigue cracking. Similarly, test results show that, at same volume concentration of binder, QC rock asphalt exhibited the best self-healing properties followed by UM and Buton rock asphalt, respectively. This ranking was more pronounced with longer rest period durations. Test results also indicate that, at same rest period, 8% Buton rock asphalt healed better than 20% Buton rock asphalt. In addition, this paper also uses these materials to demonstrate an experimental and analytical approach to quantity both fatigue cracking resistance and self-healing properties using a viscoelastic continuum damage model and a single unified testing protocol with asphalt mortars or FAM. This approach can also be easily applied to evaluate other similar materials such as reclaimed asphalt pavements (RAP).

A unified in vitro test system for the assessment of tight junction modulators

Tight junction (TJ) modulation is a promising approach for improving drug bioavailability by enhancing the absorption of active pharmaceutical ingredients. However, the application of many different test methods to determine the efficacy of new TJ modulators (TJMs) or to assess different compounds is accompanied by a lack of comparable results, reducing the rational evaluation and commercial marketing of these pharmaceutical excipients. The establishment of unified testing methods can fill this gap and offers the opportunity to compare results from different laboratories. Furthermore, the calculation of a TJ modulation score allows the objective comparison of TJ modulators and facilitates the selection of appropriate candidates.In this study, eight well-known TJ modulators were tested with a focus on four different in vitro bioassays carried out with MDCK cells. The extent of TJ modulation was determined by transepithelial electric resistance (TEER) measurements and permeability studies with mannitol. To evaluate tolerability, cell viability (MTT) and cytotoxicity (CellTox™ Green) assays were performed, and TEER regeneration was monitored for 24 h after exposure. With the exception of labradimil, seven TJ modulators caused significant TEER reduction of up to 100 %. For five compounds, an enhancement of mannitol permeation was observed. As expected, first-generation enhancers exhibited lower cell compatibility than mechanism-based modulators. Based on the experimental results of this study, for the first time, an evaluation system (tight junction modulator scoring system, TJMSS) is presented that provides a ranking of the tested modulators depending on weighted parameters. Such a system offers the possibility of rational formulation development for drugs requiring improved absorption.

Meta-Qtest: meta-analysis of quadratic test for rare variants

BackgroundIn genome-wide association studies (GWASs), meta-analysis has been widely used to improve statistical power by combining the results of different studies. Meta-analysis can detect phenotype associated variants that are failed to be detected in single studies. Especially, in biomedical sciences, meta-analysis is often necessary not only for improving statistical power, but also for reducing unavoidable limitation in data collection. As next-generation sequencing (NGS) technology has been developed, meta-analysis of rare variants is proceeding briskly along with meta-analysis of common variants in GWASs. However, meta-analysis on a single variant that is commonly used in common variant association test is improper for rare variants. A sparse signal of rare variant undermines the association signal and its large number causes multiple testing problem. To over-come these problems, we propose a meta-analysis method at the gene-level rather than variant level.ResultsAmong many methods that have been developed, we used the unified quadratic tests (Q-tests); Q-test is more powerful than or as powerful as other tests such as Sequence Kernel Association Tests (SKAT). Since there are three different versions of Q-test (QTest1, QTest2, QTest3), each assumes different relationships among multiple rare variants, we extended them into meta-study accordingly. For meta-analysis, we consider two types of approaches, the one is to combine regression coefficients and the other is to combine test statistics from each single study. We extend the Q-test for meta-analysis, proposing Meta Quadratic Test (Meta-Qtest). Meta Q-test avoids the limitations of MetaSKAT. It does not only consider genetic heterogeneity among studies as MetaSKAT but also reflects diverse real situations; since we extend three different Q-tests into meta-analysis respectively, flexible Meta Q-test suggests way to deal with gene-level rare variant meta-analysis efficiently From the results of real data analysis of blood pressure trait, our meta-analysis could successfully discovered genes, KCNA5 and CABIN1 that are already well known for relevance with hypertension disease and they are not detected in MetaSKAT.ConclusionAs exemplified by an application to T2D Genes projects data set, Meta-Qtest more effectively identified genes associated with hypertension disease than MetaSKAT did.

Unified Inference for an AR Process Regardless of Finite or Infinite Variance GARCH Errors*

Statistical inference in finance often depends on certain moment conditions such as finite or infinite variance, yet it is practically challenging to disentangle these conditions. This article develops a class of unified unit root tests for AR(1) models and a weighted least squares estimator along with robust inference for a stationary AR(r) model regardless of finite or infinite variance GARCH errors. The inferential framework applies the empirical likelihood method to some weighted score equations without estimating the GARCH errors. In contrast to extant unit root tests relying on bootstrap or subsampling methods to approximate critical values, the proposed unit root tests can be easily implemented with critical values obtained directly from a chi-squared distribution using the Wilks theorem. Extensive simulation studies confirm the good finite sample performance of the proposed methods before we illustrate them empirically with financial ratios for stock return predictability and HKD/USD exchange rate returns.

Biaxial Mechanical Characterizations of Atrioventricular Heart Valves.

Extensive biaxial mechanical testing of the atrioventricular heart valve leaflets can be utilized to deriveoptimal parameters used in constitutive models, which provide a mathematical representation of the mechanical function of those structures. This presented biaxial mechanical testing protocol involves (i) tissue acquisition, (ii) the preparation of tissue specimens, (iii) biaxial mechanical testing, and (iv) postprocessing of the acquired data. First, tissue acquisition requires obtaining porcine or ovine hearts from a local Food and Drug Administration-approved abattoir for later dissection to retrieve the valve leaflets. Second, tissue preparation requires using tissue specimen cutters on the leaflet tissue to extract a clear zone for testing. Third, biaxial mechanical testing of the leaflet specimen requires the use of a commercial biaxial mechanical tester, which consists of force-controlled, displacement-controlled, and stress-relaxation testing protocols to characterize the leaflet tissue's mechanical properties. Finally, post-processing requires the use of data image correlation techniques and force and displacement readings to summarize the tissue's mechanical behaviors in response to external loading. In general, results from biaxial testing demonstrate that the leaflet tissues yield a nonlinear, anisotropic mechanical response. The presented biaxial testing procedure is advantageous to other methods since the method presented here allows for a more comprehensive characterization of the valve leaflet tissue under one unified testing scheme, as opposed to separate testing protocols on different tissue specimens. The proposed testing method has its limitations in that shear stress is potentially present in the tissue sample. However, any potential shear is presumed negligible.

Limiting factors of Striped Hyaena, Hyaena hyaena, distribution and densities across climatic and geographical gradients (Mammalia: Carnivora)

Few previous studies on the factors that affect Striped Hyaena (Hyaena hyaena Linnaeus, 1758) occurrence and densities were done on geographically unrelated populations using different methodologies. In Israel, hyaenas occur throughout the country's steep climatic and geographical gradients, presenting a unique opportunity to study densities and habitat use across adjacent ecosystems using a unified methodology and test previous conceptions regarding the species’ habitat selection. We collected hyaena abundance-absence data using 1440 camera traps placed at 80 sites (2012– 2016). Site location ranged from hyper-arid deserts to dense Mediterranean shrubland. We assessed the effect of climate, habitat structure, elevation, geomorphological attributes (proxy for den availability), and anthropogenic development (proximity to settlements and agriculture) on hyaena densities using N-mixture models. Hyaena densities were negatively affected by anthropogenic development, and were limited by den availability. Hyaena densities did not follow a climatic or geographic gradient. Densities were highest at hyper-arid deserts and Mediterranean coastal shrublands. Despite the former conception that hyaenas prefer semi-arid open habitats and avoid extreme deserts and dense vegetation, we show that hyaenas use and even thrive in these habitats when geomorphological conditions are suitable and resources are available.

A statistical framework for cross-tissue transcriptome-wide association analysis.

Transcriptome-wide association analysis is a powerful approach to studying the genetic architecture of complex traits. A key component of this approach is to build a model to impute gene expression levels from genotypes by using samples with matched genotypes and gene expression data in a given tissue. However, it is challenging to develop robust and accurate imputation models with a limited sample size for any single tissue. Here, we first introduce a multi-task learning method to jointly impute gene expression in 44 human tissues. Compared with single-tissue methods, our approach achieved an average of 39% improvement in imputation accuracy and generated effective imputation models for an average of 120% more genes. We describe a summary-statistic-based testing framework that combines multiple single-tissue associations into a powerful metric to quantify the overall gene-trait association. We applied our method, called UTMOST (unified test for molecular signatures), to multiple genome-wide-association results and demonstrate its advantages over single-tissue strategies.

DATeS: a highly extensible data assimilation testing suite v1.0

Abstract. A flexible and highly extensible data assimilation testing suite, named DATeS, is described in this paper. DATeS aims to offer a unified testing environment that allows researchers to compare different data assimilation methodologies and understand their performance in various settings. The core of DATeS is implemented in Python and takes advantage of its object-oriented capabilities. The main components of the package (the numerical models, the data assimilation algorithms, the linear algebra solvers, and the time discretization routines) are independent of each other, which offers great flexibility to configure data assimilation applications. DATeS can interface easily with large third-party numerical models written in Fortran or in C, and with a plethora of external solvers.

Global Factor Premiums

We examine 24 global factor premiums across equity, bond, commodity and currency markets via replication and out-of-sample evidence between 1800 and 2016. Replication yields ambiguous evidence within a unified testing framework that accounts for p-hacking. Out-of-sample tests reveal strong and robust presence of the large majority of global factor premiums, with limited out-of-sample decay of the premiums. We find global factor premiums to be generally unrelated to market, downside, or macroeconomic risks in the 217 years of data. These results reveal significant global factor premiums that present a challenge to traditional asset pricing theories.

Ceramic-based photocatalytic membrane reactors for water treatment – where to next?

Abstract Ceramic-based photocatalytic membrane reactors (cPMRs) are becoming increasingly popular among researchers and will soon be seen on the water/wastewater-treatment market. This review provides a thorough analysis of the available data on cPMRs fabricated to date based on coating method, support and coating materials, membrane design, pore size and model compounds used to evaluate process efficiency and light source. While all of the studies describe cPMR preparation in great detail, over half do not provide any information about their performance. The rest used various dyes that can be conveniently detected by spectrophotometry/fluorimetry, or micropollutants that require analytical equipment available only in specialized laboratories. In addition, cPMRs are viewed as a convenient way of incorporating a photocatalyst on an inert surface assuming that the surface itself, i.e. the membrane, does not participate in the treatment process. A unified test for cPMR performance should be developed and implemented for all cPMRs that have the potential for commercialization. There is a need for standardization in cPMR testing; only then can the true performance of cPMRs be evaluated and compared. Such testing will also answer the question of whether the cPMR membrane is indeed an inert support or an active part of the treatment process.

Detecting trend change in hazard functions—an L-statistic approach

A unified test is proposed to detect trend change in hazard functions. Test statistics based on a weighted integral approach are constructed utilizing a measure of deviation from exponentiality. We exploit L-statistic theory to obtain the exact and asymptotic distributions of our statistics and establish the consistency of the test. Theoretical results of previous works are obtained as special cases. A simulation study shows significant improvement in power depending on appropriate choice of parameters j and k introduced in our work. Finally, applications to real life data sets are presented to illustrate our results.

Research on measurement of electromagnetic fields generated by electric and combustion powered rolling stock.

Axle counters are more and more often applied in train detection systems. The wheel sensor is a main part of each axle counter system. In parallel, more and more complex railway vehicles, especially traction ones, are a potential source of interferences influencing the operation of these train detection systems. It is the reason to verify the electromagnetic compatibility (EMC) between the signalling equipment, particularly train detection systems and new vehicles in the process of obtaining the permission for their exploitation. The measurement of interfering magnetic fields generated by vehicles is one of tests to be carried out. For the simplification and unification purpose of the applied interference test methods the EN 50238 standard and TS 50238-3 technical specification were developed. The specification defines unified testing procedures. However, it is necessary to verify if it may replace different testing methods used in particular European states. It is the goal of the European research project financed from the TEN-T network resources.

Effect of TXNRD2 rs35934224, FOXC1 rs2745599 and rs984253 genetic polymorphisms combinations on the development of primary open-angle glaucoma and their degree of association with the disease

Primary open-angle glaucoma (POAG) is a complex disease caused by numerous genetic and environmental factors, as well as their interaction. In recent studies, the effect of genetic polymorphisms combinations and non-equilibrium linkage of allele genes related to the development of POAG has been proved. The aim of the study was to determine the effect of TXNRD2 rs35934224, FOXC1 rs2745599 and rs984253 genetic polymorphisms combinations on the development of primary open-angle glaucoma and their degree of association with the disease. The study included 93 patients (185 eyes) with POAG stage I-IV and 89 volunteers (178 eyes) control subjects without any types of glaucoma. The patients were divided into four groups according to the degree of perimetric changes (Nesterov A. P., 2008). All patients performed visometry, computer perimetry, tonometry, biomicroscopy, ophthalmoscopy, gonioscopy, keratopahymetry, optical coherent tomography of the optic nerve. Analysis of the TXNRD2 rs35934224, FOXC1 rs2745599 and rs984253 genetic polymorphism with POAG was performed in real time using a polymerase chain reaction (PCR) in Gene Amp® PCR System 7500 (Applied Biosystems, USA) automatic amplifier. In the first stage of the study, the genomic DNA from whole venous blood was isolated using the standard reagents PureLink® Genomic DNA Kit for purification of genomic DNA, manufactured by INVITROGEN (USA). The analysis of polymorphism was carried out using unified test systems of TaqMan Mutation Detection Assays Life-Technology (USA). It was determined that the association with POAG had the genotype C/T*A/A*T/A as by comparing control with all patients, and by stratification – with the 1st, 2nd and 3rd groups of patients. The obtained results showed the evidentiary effect of this genotype combinations on the appearance of POAG, and on its progression by the stages of perimetric changes. The risk of the occurrence of POAG in carriers of genotypes C/T*A/A*T/A was increased by 2.8 times (p<0.001). In this combination, the two polymorphisms had heterozygous genotypes (rs35934224 – C/T, rs984253 – T/A), and the genotype rs2745599 – a mutant homozygote A/A. A combination of genotypes C/C*G/A*T/A was also important for the progression of the disease till stage II, which increased the risk of development of the POAG stage II by 2.9 times (p<0.01) compared to control. The risk of occurrence of the POAG in general and development of stage IV increased the presence of combinations of three minor genotypes T/T*A/A*A/A, which was encountered only in patients with POAG (in stage II – f = 0.025, in the third stage – f = 0.036, and in IV – f = 0.071). In our opinion, it confirmed the proposed working hypothesis of the study and showed that the more genotype combinations have the mutant alleles, the stronger this genotype affects the development of POAG.

A unified approach to testing mean vectors with large dimensions

A unified testing framework is presented for large-dimensional mean vectors of one or several populations which may be non-normal with unequal covariance matrices. Beginning with one-sample case, the construction of tests, underlying assumptions and asymptotic theory, is systematically extended to multi-sample case. Tests are defined in terms of U-statistics-based consistent estimators, and their limits are derived under a few mild assumptions. Accuracy of the tests is shown through simulations. Real data applications, including a five-sample unbalanced MANOVA analysis on count data, are also given.

Fault-Tolerant Unicast-Based Multicast for Reliable Network-on-Chip Testing

We present a unified test technique that targets faults in links, routers, and cores of a network-on-chip design based on test sessions. We call an entire procedure, that delivers test packets to the subset of routers/cores, a test session. Test delivery for router/core testing is formulated as two fault-tolerant multicast algorithms. Test packet delivery for routers is implemented as a fault-tolerant unicast-based multicast scheme via the fault-free links and routers that were identified in the previous test sessions to avoid packet corruption. A new fault-tolerant routing algorithm is also proposed for the unicast-based multicast core test delivery in the whole network. Identical cores share the same test set, and they are tested within the same test session. Simulation results highlight the effectiveness of the proposed method in reducing test time.

EXPERIENCE GAINED DURING EXAMINATION OF ELECTROMAGNETIC COMPATIBILITY BETWEEN ROLLING STOCK AND AXLE COUNTERS

Axle counters are more and more often applied in train detection systems. The wheel sensor is a main part of each axle counter system. In parallel, more and more complex railway vehicles, especially traction ones, are a potential source of interferences influencing the operation of these train detection systems. It is the reason to verify the electromagnetic compatibility (EMC) between the signalling equipment, particularly train detection systems and new vehicles in the process of obtaining the permission for their exploitation. The measurement of interfering magnetic fields generated by vehicles is one of tests to be carried out. For the simplification and unification purpose of the applied interference test methods the EN 50238 standard and TS 50238-3 technical specification were developed. The specification defines unified testing procedures. However, it is necessary to verify if it may replace different testing methods used in particular European states. It is the goal of the European research project financed from the TEN-T network resources. This project is part of the larger project of facilitation and speeding up the ERTMS system deployment. One of nine measurement campaigns planned in the frame of this project was conducted in Poland by Railway Research Institute.

Alternative treatment regimens in autoimmune hepatitis: how justified is their choice?

Autoimmune hepatitis is a progressive immune-mediated liver disease of unknown etiology. Its key characteristics include hyper-gammaglobulinemia, circulating autoantibodies, and periportal inflammation seen in a liver biopsy sample. It is not infrequent that the lack of unified diagnostic tests makes the verification of the disease very challenging. Most patients respond well to standard immunosuppressive therapy; however, a significant proportion of them demonstrate side effects and disease relapses after treatment withdrawal. A wide range of side effects of systemic steroids and eventual disruptions with azathioprine (the agent of choice in the treatment algorithms for autoimmune hepatitis) supplies to the Russian market make it relevant to use alternative treatment regimens. In the real world practice, alternative treatment regimens are rarely used in such patients due to the absence of hard evidence of their efficacy. Low prevalence of autoimmune hepatitis, multiplicity of its clinical types, as well as a lack of understanding of its pathogenetic mechanisms hinder the synthesis of new agents and performing trials with already known immunosuppressants with a statistical power necessary to obtain persuasive data. One of solutions of the problem could be the accumulation of clinical data into registries for further systematization of the knowledge and formulation of new clinical guidelines.

A unified test for predictability of asset returns regardless of properties of predicting variables

Some unified tests have been proposed recently in the literature for testing predictability of asset returns based on a simple linear predictive regression model, which has a drawback that predicted variable cannot be stationary if the predicting variable is nonstationary. To solve this issue, this paper includes the difference of the predicting variable into the simple linear predictive regression. Furthermore, a unified empirical likelihood inference is developed to test the predictability regardless of the properties of the predicting variable. A simulation study is conducted to confirm the efficiency of the proposed methods before applying to a real example.

Genome-wide association study for multiple phenotype analysis

Genome-wide association studies often collect multiple phenotypes for complex diseases. Multivariate joint analyses have higher power to detect genetic variants compared with the marginal analysis of each phenotype and are also able to identify loci with pleiotropic effects. We extend the unified score-based association test to incorporate family structure, apply different approaches to analyze multiple traits in GAW20 real samples, and compare the results. Through simulation studies, we confirm that the Type I error rate of the pedigree-based unified score association test is appropriately controlled. In marginalanalysis of triglyceride levels, we found 1 subgenome-wide significant variant on chromosome 6. Joint analyses identified several suggestive genome-wide significant signals, with the pedigree-based unified score association test yielding the greatest number of significant results.