Zhi Quan Zhou

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An oracle is a mechanism against which the tester can decide whether the outputs of the program for the executed test cases are correct. A fundamental problem of software testing is that, in many situations, the oracle is not available or too difficult to apply. A metamorphic testing (MT) method has been proposed to alleviate the oracle problem. MT is an(More)
Random Testing (RT) is a fundamental software testing technique. Adaptive Random Testing (ART) improves the fault-detection capability of RT by employing the location information of previously executed test cases. Compared with RT, test cases generated in ART are more evenly spread across the input domain. ART has conventionally been applied to programs(More)
An “oracle” in software testing is a procedure by which testers can decide whether the output of the program under testing is correct. In some situations, however, the oracle is not available or too difficult to apply. This is known as the “oracle problem”. In other situations, the oracle is often the human tester who checks the testing result manually. The(More)
An adaptive random (AR) testing strategy has recently been developed and examined by a growing body of research. More recently, this strategy has been applied to prioritizing regression test cases based on code coverage using the concepts of Jaccard Distance (JD) and Coverage Manhattan Distance (CMD). Code coverage, however, does not consider frequency;(More)
A software product is functionally correct if it behaves according to the functional specification. Compared with other quality aspects of Web search engines such as performance and capacity, functional correctness is more fundamental but its verification suffers from the oracle problem: It is often difficult or impossible to decide whether outcomes of test(More)
BACKGROUND AND PURPOSE The diagnostic performance of 64-detector computed tomographic angiography (CTA) for detection of small intracranial aneurysms (SIAs) was evaluated. METHODS In this prospective study, 112 consecutive patients underwent 64-detector CTA before volume-rendering rotation digital subtraction angiography (VR-RDSA) or surgery. VR-RDSA or(More)
Switchable reaction patterns of β-substituted cyclic enones via amine-based dienamine activation are reported. While γ-regioselective vinylogous Michael addition was observed with alkylidenemalononitriles, a completely different [4 + 2] cycloaddition was obtained with allylidene- or alkynylidenemalononitrile substrates, affording densely substituted(More)
We present a dynamic partitioning strategy that selects test cases using online feedback information. The presented strategy differs from conventional approaches. Firstly, the partitioning is carried out online rather than off-line. Secondly, the partitioning is not based on program code or specifications; instead, it is simply based on the fail or pass(More)
Here we report that cyclic 2,5-dienones can act as bisvinylogous precursors through in situ generation of linear trienamine species with a cinchona-derived primary amine, and exclusively remote ε-regioselective 1,4-additions to nitroalkenes were accomplished in moderate to high enantioselectivity. Moreover, a diversity of complex spirocyclic frameworks(More)
A special challenge in the field of asymmetric catalysis is the realization of remote stereocontrol. The problem can be extended to remote sites which must be activated to ensure better reactivity. While most early examples of remote asymmetric inductions rely on enzyme catalysis or intramolecular relay of chiral information through the substrate, current(More)