Random-Like Testing of Very Large Scale Integration Circuit

A new approach to improve the test efficiency of random testing is presented in this paper. In conventional random testing, each test pattern is selected randomly regardless of the tests previously generated. This paper introduces the concept of random like testing. The method provided appears to have the same concepts as used in random testing,but actually takes an opposite way to it in order to improve the efficiency of random testing.In a random like testing sequence, the total distance among all test patterns is chosen to be maximal so that the fault sets detected by one test pattern are as different as possible from that detected by the tests previously applied. The procedure to construct a random like testing sequence (RLTS) is described in detail. Theorems to justify the effectiveness and usefulness of the procedure presented are developed. Experimental results on benchmark circuits as well as on other circuit are also given to evaluate the performance of the new approach.

Predicting test data of aluminum honeycomb sandwich board based on volterra adaptive filters

Random vibration test was done on aluminum honeycomb sandwich board.The result suggested that chaotic behavior is found in the test data.The Volterra expression can not be gained from the input and output data directly in this paper.The state space reconstruction was used to convert the system observed data into the quasi-input/output pairs,and the second-order Volterra adaptive filter was used to predict the test data.It is shown that combining the state space reconstruction with the Volterra adaptive filter,these chaotic series could be accurately predicted.

TESTING FOR VARYING DISPERSION IN DISCRETE EXPONENTIAL FAMILY NONLINEAR MODELS

It is necessary to test for varying dispersion in generalized nonlinear models.Wei,et al(1998) developed a likelihood ratio test,a score test and their adjustments to test for varying dispersion in continuous exponential family nonlinear models.This type of problem in the framework of general discrete exponential family nonlinear models is discussed.Two types of varying dispersion,which are random coefficients model and random effects model,are proposed,and corresponding score test statistics are constructed and expressed in simple,easy to use,matrix formulas.

CONSISTENCY OF MLE OF THE PARAMETER OF EXPONENTIAL LIFETIME DISTRIBUTION FOR RANDOM CENSORING MODEL WITH INCOMPLETE INFORMATION

In this paper, we have discussed a random censoring test with incomplete information, and proved that the maximum likelihood estimator(MLE) of the parameter based on the randomly censored data with incomplete information in the case of the exponential distribution has the strong consistency.

Control method for multi-input multi-output non-Gaussian random vibration test with cross spectra consideration

A control method for Multi-Input Multi-Output（MIMO） non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified references composed of auto spectral densities, cross spectral densities and kurtoses on the test article in the laboratory. It is found that the cross spectral densities will bring intractable coupling problems and induce difficulty for the control of the multioutput kurtoses. Hence, a sequential phase modification method is put forward to solve the coupling problems in multi-input multi-output non-Gaussian random vibration test. To achieve the specified responses, an improved zero memory nonlinear transformation is utilized first to modify the Fourier phases of the signals with sequential phase modification method to obtain one frame reference response signals which satisfy the reference spectra and reference kurtoses. Then, an inverse system method is used in frequency domain to obtain the continuous stationary drive signals. At the same time, the matrix power control algorithm is utilized to control the spectra and kurtoses of the response signals further. At the end of the paper, a simulation example with a cantilever beam and a vibration shaker test are implemented and the results support the proposed method very well.

Scan BIST with biased scan test signals

The conventional test-per-scan built-in self-test （BIST） scheme needs a number of shift cycles followed by one capture cycle. Fault effects received by the scan flipflops are shifted out while shifting in the next test vector like scan testing. Unlike deterministic testing, it is unnecessary to apply a complete test vector to the scan chains. A new scan-based BIST scheme is proposed by properly controlling the test signals of the scan chains. Different biased random values are assigned to the test signals of scan flip-flops in separate scan chains. Capture cycles can be inserted at any clock cycle if necessary. A new testability estimation procedure according to the proposed testing scheme is presented. A greedy procedure is proposed to select a weight for each scan chain. Experimental results show that the proposed method can improve test effectiveness of scan-based BIST greatly, and most circuits can obtain complete fault coverage or very close to complete fault coverage.

Probabilistic Models for Estimation of Random and Pseudo-Random Test Length

A new probabilistic testability measure is presented to ease test length analyses of random testing and pseudorandom testing.The testability measure given in this paper is oriented to signal conflict of reconvergent fanouts.Test length analyses in this paper are based on a hard fault set,calculations of which are practicable and simple.Experimental results have been obtained to show the accuracy of this test length analyser in comparison with that of Savir,Chin and McCluskey,and Wunderlich by using a pseudorandom test generator combined with exhaustive fault simulation.

An Empirical Study on Automated Test Generation Tools for Java:Effectiveness and Challenges

Automated test generation tools enable test automation and further alleviate the low efficiency caused by writing hand-crafted test cases.However,existing automated tools are not mature enough to be widely used by software testing groups.This paper conducts an empirical study on the state-of-the-art automated tools for Java,i.e.,EvoSuite,Randoop,JDoop,JTeXpert,T3,and Tardis.We design a test workflow to facilitate the process,which can automatically run tools for test generation,collect data,and evaluate various metrics.Furthermore,we conduct empirical analysis on these six tools and their related techniques from different aspects,i.e.,code coverage,mutation score,test suite size,readability,and real fault detection ability.We discuss about the benefits and drawbacks of hybrid techniques based on experimental results.Besides,we introduce our experience in setting up and executing these tools,and summarize their usability and user-friendliness.Finally,we give some insights into automated tools in terms of test suite readability improvement,meaningful assertion generation,test suite reduction for random testing tools,and symbolic execution integration.

Evaluation of the Potential Inhibitory Activity of A Combination of L.Acidophilus,L.Rhamnosus and L.Sporogenes on Helicobacter Pylori：A Randomized Double-Blind Placebo-Controlled Clinical Trial

Objective： To investigate whether three strains of probiotics, L. acidophilus, L. rhamnosus, and L. sporogenes, had significant inhibitive effects on Helicobacter pylori（H. pylori）. Methods： This is a 4-week, randomly assigned, parallel-group, doubled-blind, and placebo-controlled study. Fifty patients with a positive H. pylori infection urea breath test（△UBT） result 〉 10% and without ulcer symptoms were randomized into a treatment group and a placebo group by a computer generated allocation sheet with 1：1. These subjects took one capsule of probiotics or placebo twice daily. The primary measurement was the change in △UBT values. Results： The △UBT values during the 4-week treatment period and the 2-week follow-up period were not significantly different between the treatment group and the placebo group, indicating that the inhibitive effects on H. pylori were comparable between both groups. The monocyte count（%） was 5.77±1.11 in the treatment group versus 5.09±1.12 in the placebo group（P=0.044）, and the basophile count was 0.55±0.32 in the treatment group versus 0.36±0.23 in the placebo group（P=0.024） at week 2 of the treatment period, both of which reached statistical significance. The monocyte count was 5.75±1.26 in the treatment group and 4.72±0.99 in the placebo group at the end of the follow-up period（P=0.003）. Conclusions： There was no significant inhibitive effects of the three probiotic strains（L. acidophilus, L. rhamnosus, and L. sporogenes） on H. pylori. Probiotics can not play the same role as antibiotics in the eradication of H. pylori, the role of probiotics is likely to be important as adjuvant to the triple or quadruple therapy for H. pylori, especially in resistance cases.

On the Longest Length of Consecutive Integers

Choose m numbers from the set {1,2,... ,n} at random without replacement. In this paper we first establish the limiting distribution of the longest length of consecutive integers and then apply the result to test randomness of selecting numbers without replacement.