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91.
Data collection, both automatic and manual, lies at the heart of all empirical studies. The quality of data collected from
software informs decisions on maintenance, testing and wider issues such as the need for system re-engineering. While of the
two types stated, automatic data collection is preferable, there are numerous occasions when manual data collection is unavoidable.
Yet, very little evidence exists to assess the error-proneness of the latter. Herein, we investigate the extent to which manual
data collection for Java software compared with its automatic counterpart for the same data. We investigate three hypotheses
relating to the difference between automated and manual data collection. Five Java systems were used to support our investigation.
Results showed that, as expected, manual data collection was error-prone, but nowhere near the extent we had initially envisaged.
Key indicators of mistakes in manual data collection were found to be poor developer coding style, poor adherence to sound
OO coding principles, and the existence of relatively large classes in some systems. Some interesting results were found relating
to the collection of public class features and the types of error made during manual data collection. The study thus offers
an insight into some of the typical problems associated with collecting data manually; more significantly, it highlights the
problems that poorly written systems have on the quality of visually extracted data. 相似文献
92.
In long-term memory, negative information is better remembered than neutral information. Differences in processes important to working memory may contribute to this emotional memory enhancement. To examine the effect that the emotional content of stimuli has on working memory performance, the authors asked participants to perform working memory tasks with negative and neutral stimuli. Task accuracy was unaffected by the emotional content of the stimuli. Reaction times also did not differ for negative relative to neutral words, but on an n-back task using faces, participants were slower to respond to fearful faces than to neutral faces. These results suggest that although emotional content does not have a robust effect on working memory, in some instances emotional salience can impede working memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
93.
防霉建筑涂料的研究与施工使用 总被引:1,自引:1,他引:0
针对国内外防霉建筑涂料存在的问题,研制开发了以合成树脂为主要成膜物质,加入环保性杀菌防霉剂及具有防腐霉的功能性颜填料,再配以树脂固化剂等成分配制而成的高性能防霉建筑涂料,并指出该涂料防霉效果良好。 相似文献
94.
Previous research yielded inconsistent results regarding the memory organization of self-performed actions. The authors propose that task performance changes the very basis of memory organization. Enactment during study and test (Experiment 1) yielded stronger enactive clustering (based on motor-movement similarities), whereas verbal encoding yielded stronger conceptual clustering (based on semantic-episodic similarities). Enactment enhanced memory quantity and memory accuracy. Both measures increased with enactive clustering under self-performance instructions but with conceptual clustering under verbal instructions. Enactment only during study (Experiment 2) or only during testing (Experiment 3) also enhanced enactive clustering. It is proposed that different conditions affect the relative salience of different types of memory organization and their relative contribution to recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
95.
In this work, we co‐formulated an oil‐borne copper naphthenate/permethrin wood preservative system with synthetic polymer‐based fire‐retardant additives prior to the impregnation of Pinus radiata sapwood. We evaluated what effect, if any, the preservative had upon the fire performance properties of the fire retardants and whether the fire retardants impacted on the fungicidal and termiticidal efficacy of the preservative. The fire retardants included halogenated and phosphorus‐based systems. A mass loss calorimeter, in conjunction with a thermopile, was used to measure the time to ignition and the peak heat release rate (PHRR) from which the fire performance index (FPI) was determined. The preservative properties were evaluated using termite and soil‐block decay bioassays. In summary, we found that the rate of fire growth was reduced when the fire retardants were used in combination with the wood preservative. We also found that the PHRR was a better determinant of fire performance than the FPI. The performance of the wood preservative was enhanced against fungal decay and termite attack when used in combination with the fire retardants. The fire retardants also demonstrated some wood preservative properties of their own. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
96.
Patrick Musonda 《Computational statistics & data analysis》2008,52(4):1942-1957
Second-order expressions for the asymptotic bias and variance of the log relative incidence estimator are derived for the self-controlled case series model in a simplified scenario. The dependence of the bias and variance on factors such as the relative incidence and ratio of risk to observation period are studied. Small-sample performance of the estimator in realistic scenarios is investigated using simulations. It is found that, in scenarios likely to arise in practice, asymptotic methods are valid for numbers of cases in excess of 20-50 depending on the ratio of the risk period to the observation period and on the relative incidence. The application of Monte Carlo methods to self-controlled case series analyses is also discussed. 相似文献
97.
几种吸附式致冷新工质对的性能预测 总被引:3,自引:1,他引:2
应用吸附平衡基本理论对几种可能的吸附式致冷新工质对的性能进行了预测。结果表明,烷烃系列的低混点工质与沸石的配对体系是不可取的,而沸石-氨、活性炭-丙酮、活性炭-氨及活性炭-乙醇则是沸石-水、活性炭-甲醇体系的适宜的替代物。 相似文献
98.
本文从C/C复合材料的基体入手,研究了基体沥青、焦炭中添加氧化物的工艺条件及其在复合材料中的作用.结果表明,添加氧化物对基体改性,不仅能提高C/C复合材料的高温抗氧化性,也能对其它性能带来很大影响.只要控制适当的工艺条件,就可以得到高性能的C/C复合材料. 相似文献
99.
胡才雄 《有色金属材料与工程》1992,(1)
结合器件工艺的失效分析,评述了硅中缺陷和氧、碳、金属杂质与器件性能、器件工艺之间的相互关系。指出:杂质和缺陷对器件的性能、成品率和可靠性有严重的影响,尤其经金属杂质缀饰的缺陷对器件的危害更大。对硅中某些杂质和缺陷的最新研究进展作了介绍。 相似文献
100.
中国第一口超千米深水钻井液技术 总被引:3,自引:1,他引:2
LW3-1-1探井位于中国南海珠江口盆地,作业水深1480m,完钻井深为3843m,地层以大套灰色泥岩和页岩为主,具有强水敏性.要求钻井液具有良好的流变性、润滑性、抑制性,良好的抗盐、抗钙、抗高温和抗低温能力,以及强的天然气水合物抑制能力。该井采用了PFMX钻井液体系,钻井周期为49d,介绍了钻井液工艺及现场应用情况。PFMX体系表现出很多油基钻井液的优点,如好的润滑性、高的钻进速率、膜效应、强的井眼稳定及页岩抑制性,解决了强水敏性地层的井壁稳定等问题,还解决了深水钻井中遇到的挑战,如低的破裂压力梯度、天然气永合物、浅层水流、深水低温等问题,满足了该区块作业需要。 相似文献