共查询到19条相似文献，搜索用时 83 毫秒
1.
介绍了可信度方法的基本理论、基于可信度的知识和证据的不确定性描述以及可信度的更新算法,建立了基于可信度方法的OTC网上智能咨询系统推理模型.通过实例验证此推理模型推理诊断过程的正确性及可行性,并对影响推理结果准确性的关键因素——可信度因子进行了讨论及分析. 相似文献
2.
根据缺陷诊断领域知识的特点，设计了一种缺陷诊断专家系统推理控制策略。采用正反向混合推理控制策略及确定性理论来处理知识的不确定性问题。实际应用结果表明效果良好，达到了缺陷诊断要求。 相似文献
3.
基于不确定推理模型的中医诊断专家系统的研制 总被引：2，自引：0，他引：2
以中医理论知识为基础,运用基于可信度的不确定推理方法对中医的疾病诊断问题进行了研究和开发,将中医诊断知识进行了形式化阐述,设计构造了诊断专家系统的整体框架.利用人机对话的补充诊断方式提高了诊断的正确度. 相似文献
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陈宏希 《兰州石化职业技术学院学报》2015,(1):32-34
针对Jess基于规则的反向链推理,具体研究其实现反向链推理的机理,给出了Jess中反向链推理的声明和回溯规则建立的具体方法,并为使用反向链推理的问答式诊断专家系统提供设计开发的一般模式,为该模式专家系统的具体开发实现提供借鉴和参考。 相似文献
5.
应用神经网络推理技术，设计了一种基于尾气分析的发动机故障诊断专家系统。此系统将传统专家系统与神经网络技术科学地加以综合，弥补了传统专家系统的诸多缺陷。专家系统的知识库由两部分组成，即浅层知识库和深层知识库。推理过程由神经网络完成，并带有解释说明模块，主要说明诊断结果的判定依据。实践证明．这种方法能较好地解决传统专家系统存在的问题，提高系统的诊断速度和准确率。 相似文献
6.
为了控制空间碎片的数量,合理利用和保护有限的太空资源,设计基于规则推理的空间碎片减缓设计专家系统.系统采用JESS作为规则引擎,可以动态地管理和修改规则,从而提供软件系统的柔性和适应性,推理引擎不仅支持正向推理,同时也支持反向推理,采用基于规则反向推理作为正向推理的辅助手段,提高专家系统的推理效率,并实现了专家系统的自学习和自完善的功能.专家系统能指导设计人员进行航天器和运载火箭空间碎片减缓设计工作,显著提高空间碎片减缓设计水平. 相似文献
7.
田光辉 《四川职业技术学院学报》2006,16(2):106-108
介绍汽车电气故障诊断仪器现状及智能故障诊断专家系统的结构和组成,建立汽车电气故障智能诊断专家系统的知识库管理系统以及推理模块的构成和故障诊断专家系统。 相似文献
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胡睿 《中国石油大学胜利学院学报》2010,24(3)
采用基于可信度因子的不精确推理模型,建立钻井事故诊断专家系统.该系统通过知识库建立及推理机设计,由可信度分析可以对钻井过程中经常发生的各种复杂情况及事故进行及时、准确的识别和处理,从而提高钻井工作效率.钻井事故案例分析表明该方法简单实用,能够很好地为现场提供技术支持. 相似文献
10.
针对目前公众自行购买非处方药治疗常见轻微疾病的过程中存在的问题,提出了开发基于Web的常见疾病自我诊断系统。该系统采用带有可信度的产生式规则表示法来表示常见病诊断知识,采用正反向混合推理模式,通过可信度的传递以及结论阈值的设定,实现了疾病诊断的数字化。经测试,系统诊断准确度达83%。本系统对完善常见病诊断方式、指导公众安全使用非处方药具有积极的作用。 相似文献
11.
This study reports on the development and application of a four-tier multiple-choice (4TMC) diagnostic instrument, which has
not been reported in the literature. It is an enhanced version of the two-tier multiple-choice (2TMC) test. As in 2TMC tests,
its answer and reason tiers measure students’ content knowledge and explanatory knowledge, respectively. The two additional
tiers measure the level of confidence of students in the correctness of their chosen options for the answer and reason tiers
respectively. The 4TMC diagnostic test focused on the properties and propagation of mechanical waves. It was administered
to 598 upper secondary students after they were formally instructed on the foregoing topics. The vast majority of the respondents
were found to have an inadequate grasp of the topics tested. Mean scores and mean confidence associated with the answer tier
was higher than those associated with the reason tier. The students tended to be poorly discriminating between what they know
and what they do not know. Familiarity with the topic tested was associated with greater percentage of students giving correct
answers, higher confidence, and better discrimination quotient. Nine genuine alternative conceptions (which were expressed
with moderate levels of confidence by students) were identified. 相似文献
12.
Der-Ching Yang 《Educational research; a review for teachers and all concerned with progress in education》2013,55(4):368-388
Background: Number sense is a key topic in mathematics education, and the identification of children’s misconceptions about number is, therefore, important. Information about students’ serious misconceptions can be quite significant for teachers, allowing them to change their teaching plans to help children overcome these misconceptions. In science education, interest in children’s alternative conceptions has led to the development of three- and four-tier tests that not only assess children’s understandings and misconceptions, but also examine children’s confidence in their responses. However, there are few such tests related to mathematical content, especially in studies of number sense.Purpose: The purpose of this study was to investigate children’s performance and misconceptions with respect to number sense via a four-tier diagnostic test (Answer Tier → Confidence rating for Answer Tier → Reason Tier → Confidence rating for Reason Tier).Design and method: A total of 195 fifth graders (10–11 years old) from Taiwan participated in this study. The four-tier test was web-based and contained 40 items across five components of number sense.Findings: The results show that (1) students’ mean confidence rating for the answer tier was significantly higher than for the reason tier; (2) an average of 68% of students tended to have equal confidence ratings in both answer and reason tiers; (3) students who chose correct answers or reasons had higher mean confidence ratings in most items (36 out of 40) than those who did not; and (4) 16 misconceptions were identified and most of them were at a strong level.Conclusion: The four-tier test was able to identify several misconceptions in both the answer and reason tier and provide information about the confidence levels. By using such information, teachers may be better positioned to understand the nature of learners’ misconceptions about number sense and therefore support their pupils’ progress in mathematics. 相似文献
13.
Imelda Caleon 《International Journal of Science Education》2013,35(7):939-961
This study focused on the development and application of a three‐tier multiple‐choice diagnostic test (or three‐tier test) on the nature and propagation of waves. A question in a three‐tier test comprises the content tier, which measures content knowledge; the reason tier, which measures explanatory knowledge; and the confidence tier, which measures the strength of conceptual understanding of the respondents. This paper presents results based on the responses of 243 Grade 10 students after they were formally instructed on the topic. The vast majority of the respondents showed an inadequate grasp of concepts about waves. Eleven alternative conceptions (ACs), which were expressed with confidence by more than 10% of the students, were identified; four of these ACs were expressed with high confidence. 相似文献
14.
针对特征信号淹没于噪声信号的情况,采用Morlet小波分析实现了对原始电流特征信号的降噪.同时,采用基于RBF神经网络的最优化插值与具有频谱细化特性的CZT分析,提升了频谱分辨率,充分展现了发生故障时电流特征信号的频谱细节,为电机故障诊断系统提供了可靠的诊断依据.建立了基于改进型BP神经网络的电机故障模糊诊断系统,抽象出了偏心故障的诊断规则.实测结果表明,该系统能够可靠地诊断电机的偏心故障. 相似文献
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为了提高南京某所某型雷达伺服系统故障诊断准确率,考虑到传统故障诊断算法的局限性,提出一种基于 Stacking 集成算法的雷达伺服系统故障诊断方法。针对某所某型雷达伺服系统的历史监测数据,首先采用孤立森林算法识别异常样本|然后基于原始数据构造出新的特征,使用卡方检验进行特征选择,并使用SMOTE 算法解决样本不平衡问题|最后,通过建立一种新颖、准确的基于 XGBoost、随机森林和 BP 神经网络的Stacking 集成模型进行故障诊断。实验结果表明,该方法在测试集上的诊断准确率达到了 96.2%,比传统方法诊断准确率提高了 1.8%,证明该方法能够很好地完成雷达伺服系统故障诊断任务。 相似文献
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陈明洁 《佳木斯教育学院学报》2012,(2):200+214
诊断和训练是教学的重要手段与内容,而自主设计和开发的高职英语在线诊断和训练系统不仅为学生的个性化自主学习和终身学习提供及时的反馈和诊断性建议,同时对高职英语教学起到一定的指导作用。本文旨在讨论如何构建高职英语在线诊断和训练系统。 相似文献
18.
李美荣 《商丘职业技术学院学报》2009,8(2):66-67
液压系统的工作一般是可靠的,但由于某些原因产生的一些故障具有隐蔽性和随机性等特点,使得利用单一的方法对故障的诊断有一定困难．运用综合的诊断方法,提高了故障诊断的效率和准确性． 相似文献
19.
通过对车载故障诊断系统（OBD-Ⅱ）所使用的通信协议和诊断模式的深入研究,提出了基于OBD-Ⅱ的汽车故障实时提示系统的设计方案,完成了系统总控单元与汽车OBD之间信号转化接口、总控单元、初步的专家诊断系统、文字显示及语音播报系统的软硬件开发设计和制作．样机测试结果表明,所开发的系统能够顺利地从汽车ECU获取数据流及故障信息,借助专家诊断系统能对故障原因进行综合分析,向驾驶员提供故障信息及处理故障的应对措施,并能用文字显示和语音播报这些信息,该提示系统的推广使用将有效降低汽车使用维修费用,同时对提高车辆道路交通安全性将发挥积极作用。 相似文献