蜕变测试和断言检查的比较与实验研究

在软件测试中,测试预言是一种用于检查程序在测试中是否正常运行的机制.然而在某些实际情况下,还无法制定测试预言或者难以有效地应用测试预言.针对此类测试预言问题,蜕变测试于近年应运而生,但蜕变测试的效率问题还没有被充分地加以研究.作者用控制实验的方法研究了使用蜕变测试的成本及效率,进而将蜕变测试和常用的断言检查两种方法的错误检测率和时间成本进行了比较和分析.实验结果表明,相比于断言检查方法,蜕变测试具有检测到更多错误的潜力.通过分析蜕变测试的效率和性能,与断言测试相比,蜕变测试的错误检测率更高效而效率有待提高,可适用于较为粗粒度的测试需求.     

Haemoglobins of the shark, Heterodontus portusjacksoni II. Amino acid sequence of the alpha-chain

The amino acid sequence of the alpha-chain of the principal haemoglobin from the shark, H. portusjacksoni has been determined. The chain has 148 residues and is acetylated at the amino terminal. The soluble peptides obtained by tryptic and chymotryptic digestion of the protein or its cyanogen bromide fragments were isolated by gel filtration, paper ionophoresis and paper chromatography. The amino acid sequences were determined by the dansyl-Edman procedure. The insoluble "core" peptide from the tryptic digestion contained 34 residues and required cleavage by several prosteases before the sequence was established. Compared with human alpha-chain there are 88 amino acid differences including the additional seven residues which appear on the amino terminal of the shark chain. There is also one deletion and one insertion. The chain contains no tryptophan but has four cysteinyl residues which is the highest number of such residues recorded for a vertebrate globin. In the alpha1beta1 contact sites there are four changes in the oxyhaemoglobin form and six deoxy form. Nine of the 16, alpha1beta1 contact sites show variation while three of the haem contact sites have changed in comparison to the residues known to be involved in these interactions in horse haemoglobin alpha-chain. Use of the sequence data to estimate a time of divergence of the shark from the main vertebrate line yielded the value of 410 +/- 46 million years. The data, in general, support the palaeontological view that bony fishes arose before the elasmobranchs.     

Is MT translation? Reflections on a recent assault

This essay discusses the claims made by Hofstadter (1997) that machine translation research, as a result of its commercial aims, is based on a ‘pure content’ view of language, which is unrealistic even for specialized domains. The paper argues that this simplified view of language and translation cannot be blamed solely on industrial research; it is a tenet of basic research MT as well, and one that MT shares with much of AI. The question of whether there is a fundamental difference between narrow domain and general translation is discussed in the light of Melby's (1995) notion of a ‘wall’ between terms and general vocabulary.     

A music symbols recognition method using pattern matching along with integrated projection and morphological operation techniques

Multimedia Tools and Applications - Optical Music Recognition (OMR) can be divided into three main phases: (i) staff line detection and removal. The goal of this phase is to detect and to remove...     

Housing and management characteristics of calf automated feeding systems in the Upper Midwest of the United States

Automated milk feeders are used by dairy producers to manage preweaned calves in group housing, but little is known about how these feeding systems are being used in the United States. To better understand how US dairy producers are operating these systems, this study investigated characteristics of barn design, environment, and management practices on 38 farms in the Upper Midwest of the United States via a questionnaire and on-farm measurements. Farms using automated feeders ranged in size from 7 to 300 calves on site. Natural ventilation was used on 50% of the farms, followed by barns with mechanical ventilation (39.5%), tunnel ventilation (7.9%), or outdoor facilities (sheltered plastic domes; 2.6%). Calves were kept in groups of 17.6 ± 9.8 animals (range: 5.9 to 60.5) with an average space allowance of 4.6 ± 2.0 m²/animal (range: 1.6 to 11.9). Calves on these farms received 3.7 ± 0.75 L (range: 2 to 6) of colostrum, but 22% of the tested calves had serum total protein values lower than 5.0 g/dL. Calves had an initial daily allowance of 5.4 ± 2.1 L (range: 3 to 15 L) of milk or milk replacer, rising to a peak amount of 8.3 ± 2.0 L (range: 5 to 15 L) over 18 ± 11.4 d (range: 0 to 44 d). Milk replacer was fed to calves on 68.4% of the farms compared with whole milk supplemented with nutrient balancer on 23.7% and whole milk alone on 7.9% of the farms. Calves were completely weaned at 56.8 ± 9.0 d of age (range: 40 to 85.5) and 52.1 ± 7.5 d (range: 40 to 79) since introduction into the group pen with the feeder. Notably, bacterial contamination of milk was common; the median coliform count was 10,430 cfu/mL (interquartile range: 233,111; range: 45 to 28,517,000) and standard plate count was 2,566,867 cfu/mL (interquartile range: 15,860,194; range 6,668 to 82,825,000) for samples collected from the feeder tube end (or feeder hose). Some areas of deficiency might be of concern as they might be influencing the success of using automated calf feeding systems. In particular, a better understanding of the dynamics of pathogen load is needed in both the group pen area and in the automated feeder unit itself, as these reservoirs represent significant risk to calf health and welfare.     

The relationship of chronic mucin secretion to airway disease in normal and CFTR-deficient mice

In the cystic fibrosis (CF) patient, lung function decreases throughout life as a result of continuous cycles of infection, particularly with Pseudomonas aeruginosa and Staphylococcus aureus. The mechanism underlying the pathophysiology of the disease in humans has not been established. However, it has been suggested that abnormal, tenacious mucus, resulting perhaps from improper hydration from loss of Cl- secretion via the cystic fibrosis transmembrane conductance regulator (CFTR) protein, impairs clearance of bacteria from the CF airway and provides an environment favorable to bacterial growth. If this hypothesis is correct, it could explain the absence of respiratory disease in CFTR-deficient mice, since mice have only a single submucosal gland and display few goblet cells in their lower airways, even when exposed to bacteria. To test this hypothesis further, we induced allergic airway disease in CFTR-deficient mice. We found that induction of allergic airway disease in mice, unlike bacterial infection, results in an inflammatory response characterized by goblet cell hyperplasia, increased mucin gene expression, and increased production of mucus. However, we also found that disease progression and resolution is identical in Cftr-/- mice and control animals. Furthermore, we show that the presence of mucus in the Cftr-/- airway does not lead to chronic airway disease, even upon direct inoculation with S. aureus and P. aeruginosa. Therefore, factors in addition to the absence of high levels of mucus secretion protect the mouse from the airway disease seen in human CF patients.     

Treatment of insomnia. Getting to the root of sleeping problems

Insomnia may be periodic and transient, as caused by situational stress, or persistent, as caused by a chronic sleep disorder. Physicians can gain much information concerning the type, probable cause, onset, and duration of insomnia through history taking. A sleep diary may reveal helpful information, and input from the patient's sleeping partner can also be valuable. Complicating disorders, such as heart failure, prostatism, or depression, should be sought and specific treatment prescribed. Chemical dependency, too, requires appropriate treatment. These measures, institution of good sleep-hygiene practices, and behavior modification may resolve sleeplessness. The primary indication for use of hypnotic agents is transient sleep disruption caused by acute stress. When an agent is chosen, onset of action, metabolism, and side effects should be considered, especially in elderly patients. Addictive agents should not be given to patients with substance abuse problems. If insomnia persists, evaluation at a sleep-disorder center is recommended to facilitate design of an appropriate therapeutic regimen.