Tests of Functional Form and Heteroscedasticity

This paper considers tests of misspecification in a heteroscedastic transformation model. We derive Lagrange multiplier (LM) statistics for (i) testing functional form and heteroscedasticity jointly, (ii) testing functional form in the presence of heteroscedasticity, and (iii) testing heteroscedasticity in the presence of data transformation. We present LM statistics based on the expected information matrix. For cases (i) and (ii), this is done assuming the Box-Cox transformation. For case (iii), the test does not depend on whether the functional form is estimated or pre-specified. Small-sample properties of the tests are assessed by Monte Carlo simulation, and comparisons are made with the likelihood ratio test and other versions of LM test. The results show that the expected-information based LM test has the most appropriate finite-sample empirical siFunctional Form, Hetersocedasticity, Lagrange Multiplier Test

Tests of Functional Form and Heteroscedasticity

This paper considers tests of misspecification in a heteroscedastic transformation model. We derive Lagrange multiplier (LM) statistics for (i) testing functional form and heteroscedasticity jointly, (ii) testing functional form in the presence of heteroscedasticity, and (iii) testing heteroscedasticity in the presence of data transformation. We present LM statistics based on the expected information matrix. For cases (i) and (ii), this is done assuming the Box-Cox transformation. For case (iii), the test does not depend on whether the functional form is estimated or pre-specified. Small-sample properties of the tests are assessed by Monte Carlo simulation, and comparisons are made with the likelihood ratio test and other versions of LM test. The results show that the expected-information based LM test has the most appropriate finite-sample empirical sizeFunctional Form, Heterscedasticity, Lagrange Multiplier Test

Testing of large number multiplication functions in cryptographic systems

Integer multiplication is one of the fundamental functions in cryptographic systems. Although much research has already been done on the testing of multiplication functions, most does not meet the need of cryptographic systems, where very large numbers are involved. Others provide only probabilistic algorithms. In this paper we propose an efficient deterministic algorithm for verifying large number multiplications in cryptographic systems. A deterministic oracle for large integer multiplication functions will result. In addition, our method can also be used to verify selected segments of digits in the product of two numbers.published_or_final_versio

Fault localization based only on failed runs

Fault localization commonly relies on both passed and failed runs, but passed runs are generally susceptible to coincidental correctness and modern software automatically produces a huge number of bug reports on failed runs. FOnly is an effective new technique that relies only on failed runs to locate faults statistically. © 2012 IEEE.published_or_final_versio

Editorial: Focus section on quality software

postprin

Pick, mix or match? A discussion of theories for management accounting research

This paper presents a review on applications of four types of theories for management accounting (MA) research (contingency theory, agency theory, sociological theories and psychological theories) and comments on prospects of combining multiple theories in future MA research. Based on a review of studies that adopted the four types of theories, the authors argue that multiple theories can be applied jointly in future research to enrich our understandings on MA practices from multiple perspectives. However, theories should maintain their distinctiveness in their applications. Blending multiple theories into a single all-purpose theory can be counterproductive due to loss of explanatory power.<br /

Precise propagation of fault-failure correlations in program flow graphs

Statistical fault localization techniques find suspicious faulty program entities in programs by comparing passed and failed executions. Existing studies show that such techniques can be promising in locating program faults. However, coincidental correctness and execution crashes may make program entities indistinguishable in the execution spectra under study, or cause inaccurate counting, thus severely affecting the precision of existing fault localization techniques. In this paper, we propose a BlockRank technique, which calculates, contrasts, and propagates the mean edge profiles between passed and failed executions to alleviate the impact of coincidental correctness. To address the issue of execution crashes, Block-Rank identifies suspicious basic blocks by modeling how each basic block contributes to failures by apportioning their fault relevance to surrounding basic blocks in terms of the rate of successful transition observed from passed and failed executions. BlockRank is empirically shown to be more effective than nine representative techniques on four real-life medium-sized programs. © 2011 IEEE.published_or_final_versionProceedings of the 35th IEEE Annual International Computer Software and Applications Conference (COMPSAC 2011), Munich, Germany, 18-22 July 2011, p. 58-6

An empirical comparison between direct and indirect test result checking approaches

The SOQUA 2006 Workshop was held in conjunction with the 14th ACM SIGSOFT International Symposium on Foundations of Software Engineering (SIGSOFT 2006/FSE-14) ACM Press, New York, NY.An oracle on software testing is a mechanism for checking whether the system under test has behaved correctly for any executions. In some situations, oracles are unavailable or too expensive to apply. This is known as the oracle problem. It is crucial to develop techniques to address it, and metamorphic testing (MT) was one of such proposals. This paper conducts a controlled experiment to investigate the cost effectiveness of using MT by 38 testers on three open-source programs. The fault detection capability and time cost of MT are compared with the popular assertion checking method. Our results show that MT is cost-efficient and has potentials for detecting more faults than the assertion checking method. Copyright 2006 ACM.preprintThis research is supported in part by a grant of the Research Grants Council of Hong Kong (project no. HKU 7145/04E), a grant of City University of Hong Kong and a grant of The University of Hong Kong

Doming Modes and Dynamics of Model Heme Compounds

Synchrotron far-IR spectroscopy and density-functional calculations are used to characterize the low-frequency dynamics of model heme FeCO compounds. The “doming” vibrational mode in which the iron atom moves out of the porphyrin plane while the periphery of this ring moves in the opposite direction determines the reactivity of oxygen with this type of molecule in biological systems. Calculations of frequencies and absorption intensities and the measured pressure dependence of vibrational modes in the model compounds are used to identify the doming and related normal modes

3D printing endobronchial models for surgical training and simulation

Lung cancer is the leading cause of cancer-related deaths. Many methods and devices help acquire more accurate clinical and localization information during lung interventions and may impact the death rate for lung cancer. However, there is a learning curve for operating these tools due to the complex structure of the airway. In this study, we first discuss the creation of a lung phantom model from medical images, which is followed by a comparison of 3D printing in terms of quality and consistency. Two tests were conducted to test the performance of the developed phantom, which was designed for training simulations of the target and ablation processes in endochonchial interventions. The target test was conducted through an electromagnetic tracking catheter with navigation software. An ablation catheter with a recently developed thermochromic ablation gel conducted the ablation test. The results of two tests show that the phantom was very useful for target and ablation simulation. In addition, the thermochromic gel allowed doctors to visualize the ablation zone. Many lung interventions may benefit from custom training or accuracy with the proposed low-cost and patient-specific phantom