辅助精神病专家(SVESTAP)的智能虚拟专家系统(IJITCS-V10-N1-7)

辅助精神病专家(SVESTAP)的智能虚拟专家系统(IJITCS-V10-N1-7)
辅助精神病专家(SVESTAP)的智能虚拟专家系统(IJITCS-V10-N1-7)

I.J. Information Technology and Computer Science, 2018, 1, 59-67

Published Online January 2018 in MECS (https://www.360docs.net/doc/54728686.html,/)

DOI: 10.5815/ijitcs.2018.01.07

Smart Virtual Expert System to Assist

Psychiatrists (SVESTAP)

Udara Srimath S. Samaratunge Arachchillage

Faculty of Computing, Department of Software Engineering, Sri Lanka Institute of Information

Technology (SLIIT), Malabe, Sri Lanka,

E-mail: samaratunge@https://www.360docs.net/doc/54728686.html,

Received: 29 July 2017; Accepted: 07 November 2017; Published: 08 January 2018

Abstract—Psychological issues in the world are exponentially growing and the treatment gap is also comparatively high. The main reason would be the shortage of expertise and time-consuming in conventional diagnose process. The main objective of this research is to lower the mental issues treatment gap of professionals or apprentices in the field by creating a virtual expert system to assist psychiatrists. This system diagnoses most common mental disorders such as Depression Disorder, Anxiety Disorder, and Dementia. The proposed expert system can communicate with patients, to identify the current state of the illness. During the conversation, a standard questionnaire is given for the disease verification purpose. The experienced mental health professionals can use this expert system to assist in diagnosing process and the apprentices of the psychology can use this expert system as a training asset.

Index Terms—Psychiatrists, Expert System, Knowledge base, Ontology, Natural Language Understanding (NLU), Natural Language Generation (NLG), Anxiety, Dementia.

I.I NTRODUCTION

Health is considered as one of the most vital factors to measure the development of the society, and mental health is significant among them. According to the current statistics, the healthcare industry is one of the top most profitable industries in the world [1]. With the evolution of this scientific knowledge, the healthcare field emerged in areas of medical drugs, treatment methods, and medical equipment and involved with performing research and development activities globally. Even though the knowledge in medicine has been expanding with the time, the patients diagnose process remains as it is since the last couple of years. When diagnosing most mental diseases of patients, the experts would provide a key contribution to determine the exact disease [2]. Based on the gained experience, experts can diagnose mental disorder conditions precisely before proceeding to treatments.

The one major problem in this field is the comparatively low availability of those professional experts and scarce finding them from hospitals in rural areas. Therefore, it would be a challenging task to determine the exact mental disorder for psychiatrists who are newly appointed for the field. Furthermore, erroneously diagnose illnesses of the patient and proceed with treatments would detrimentally impact for the patient and eventually, the whole effort would be in vain. Hence, it is impelled to develop virtual expert system in purpose of assisting for the psychiatrist is key concern. Consequently, construct knowledgebase specific to the psychological diseases can be utilized to pinpoint the exact mental illness.

II.R ELATED WORKS

There have been many types of researches and experiments were conducted to develop decision support systems as an attempt to enhance the productivity and efficacy during disease diagnose. Since healthcare domain is a vast area considering immense clinical terms it comprises, and many symptoms and diseases need to be identified, analyzed, and categorized before moving towards treatments. Mainly virtual experts use fed rules and factors to analyze the situation and make decisions but, the accuracy of the decision is the crucial factor to be considered. When analyze the existing expert systems their behavior, and implemented focus is categorically different.

A. MYCIN expert system

MYCIN was an early expert system that used artificial intelligence to identify severe infections, such as bacteremia and meningitis, and to recommend antibiotics, with the dosage adjusted for patient's body weight [3]. Furthermore, MYCIN operated using a simple inference engine, and the knowledge base embedded with rules [4]. MYCIN is one of the well-known programs that embody intelligence and provide data to behave in an intelligent manner. Compared to other artificial intelligent (AI) programs, it was slow in progress and not always in forwarding direction [3].

B. DXplain decision support system

Apart from that, DXplain is a decision support system that developed at the laboratory of computer science at the Massachusetts General Hospital, which has the characteristics of both electronic medical textbook and a

medical reference system [5]. DXplain can provide a list of clinical manifestations such as signs, symptoms, and laboratory examinations for approximately 2000 diseases [5]. Moreover, it provides justifications for each of these diseases and suggests what further clinical information should be collected pertaining to each disease. C. CADUCEUS medical expert system

In addition to that, CADUCEUS was a medical expert system completed by Harry Pople in University of Pittsburgh in 1980, which took around ten years to build the knowledge base having ability to diagnose up to 1000 different diseases [6]. Both expert systems (CADUCEUS and MYCIN) were developed using the concept of inference engine and incorporate abductive reasoning to deal with additional complexity of internal diseases [6,7]. It is hard to find the expert systems which diagnose most mental illnesses and the above-mentioned expert systems (CADUCEUS, Mycin, DXplain) are not strong enough to recognize patient’s symptoms and determine the disease exactly.

D. Mental Health Diagnostic Expert System (MeHDES) This is AI rule-based reasoning (fuzzy based reasoning) system developed using techniques such as fuzzy logic and fuzzy genetic algorithm [8], [9], [10]. This fuzzy based reasoning is one approach to construct domain knowledge. It is extended version of semantic web rule and it does not create any inconsistencies for the knowledgebase. Nevertheless, describe the ontology in fuzzy knowledgebase has limited use and fuzzy inference is limited to rules only [11]. As well this MeHDES does not support question and answering approach and system did not act as a separate human counterpart to identify the situation in a conversational manner.

Therefore, the system needs to be more dynamic and it should be further enhanced to response dynamic questions. Hence it is obvious, to develop virtual expert system rule-based reasoning is not only sufficient, whereas understanding user’s question and generate suitable answer is another essential part of it. Therefore, the proposed system fulfills the research goal by performing the role of the virtual human counterpart. Furthermore, it uses the conversational approach to diagnose the patient and its behavior is highly dynamic when making the decision ba sed on the patient’s response.

III. R ESEARCH M ETHODOLOGY

How this proposed system fulfills the key idea of the research goal is significantly considered during the system design stage. Designing smart virtual expert system is the main research problem and this can be decomposed into four substantial research questions. Refer the following Table 1 represents the defined approach that addresses each research question.

Table 1. Research based question map with defined approach

Fig.1. High-level diagram of the system

According to the high-level diagram depicted in Fig. 1 diagnostic process can be described as follows.

1. The knowledge base comprises necessary knowledge to diagnose the illness, and this is acquired by a domain expert.

2. During this diagnose process, the proposed expert

system asks questions from the patient and analyze

the patient ’s response using natural language understanding (NLU) technique.

3. This NLU technique analyzes those responses

(language: English) and extracts keywords to query the knowledge base.

4. SPARQL queries are used to query the

knowledgebase and extracts information based on the given keywords in step 3. Then find most

probable disease and send those results to the response formation process.

5. Natural language generation (NLG) technique is

used to form the response in human understandable manner.

The Fig. 2 represents interactions of each component in this proposed system.

Fig. 2. Interactions of each component in SVESTAP

A. Knowledgebase Construction for SVESTAP

The knowledgebase is the most important part in this SVESTAP to diagnose illnesses. The knowledgebase is constructed by mapping domain experts’ knowledge into an ontology [12]. For this, knowledge acquisition session is conducted with real human experts. Furthermore, to accomplish this knowledge acquisition process professional psychiatrist or panel of psychiatrists need to be interviewed through a questionnaire. This questionnaire should be meticulously planned to fully elicit the knowledge and experience of these experts. Especially, this diagnose process and judgment of diseases based on the symptoms, are performed during the discussion with patients. According to the symptoms of the patient, inference engine infers new knowledge using the embedded knowledge in the knowledge base. Ontology comprises the logical structure of data in Extensible Markup Language (XML) format and all rules pertaining to that domain can be stored as Semantic Web Rule Language (SWRL) rules [13]. During this construction process classes, object/data properties,

instances (individuals) and rules should be designed [14]. Standard books referred by psychiatrists (Eg. Diagnostic and Statistical Manual of Mental Disorder/ Mental State Examination) are used to map those details to Ontology. Fig. 5 illustrates, how classes are linked with properties to construct relationships in the knowledgebase. To implement the ontology Protégé IDE is used and Fig. 3 depicts class hierarchy related to three mental diseases. It can be visualized Onto Graph view as represented in Fig. 4.

Fig.3. Class hiarachy in domain knowledge

Fig.4. Class hiarachy in Onto Graph view

Fig.5. Ontology relationships among classes and properties

B. Understand the Query Using NLU Technique NLU technique is used to understand the answer given by the user as depicted in Fig. 6. This can be further divided into sub-processes such as (Morphology, Syntax analysis, Semantic analysis, Pragmatics and Discourse analysis) [15, 16]

Fig.6. NLU Process

1. Morphology : Initially, the system breaks the long

natural language sentence into sub-sentences to derive the meaning of it.

2. Syntax analysis : In this process, it realizes the

relationships in between sentences through syntaxes. And mainly consider how words are put together to form the correct sentences and what structural role each word has.

3. Semantics analysis : In this step, consider how

these words are combined to derive the meaning of the sentence. Hence, the system can highlight which keyword is put through the knowledgebase. 4. Pragmatics: Sometimes the sentence gives

different meaning based on the context. As a result, in this step system considers how sentences are used in different situations and how it affects the interpretation of the sentence.

5. Discourse: In here, it considers how current

sentence affects to the interpretation of the next sentence. Therefore, the system can keep track of the next sentence to match ordinary keywords which are coming from the user ’s response.

NLU sub processes perform the following tasks to

elicit keywords from the sentence.

1. Split the sentence into words (Use the delimiter of

space to split the sentence into words).

2. Identify the tag of the words (e.g. noun phrases,

nouns, verb phrases, verbs, adjective, etc.).

3. Develop a method to identify keywords of the

sentence and negation of the sentence.

4. Develop a method to identify the synonyms of

keyword related to the answer (when keywords are not matched with the given context).

5. Develop a method to check whether any spellings

or grammatical mistakes in the sentence.

6. Send extracted keywords of the sentence to

knowledgebase querying process. C. Query the Knowledgebase and Diagnosing

Keywords are extracted from above section B stage (Understand the user’s question using NLU technique) and it is used to query the constructed domain knowledge to derive the correct disease. Query answering is important in semantic web and several query languages were designed for this purpose such as Resource Description Framework Data Query Language (RDQL), Second generation Resource Description Framework Query Language (SeRQL), and most recently used SPARQL [17]. SPARQL queries can be used across diverse data sources, to verify whether the data is stored natively as RDF or viewed as RDF via middleware [18]. SPARQL contains capabilities for querying required and optional graph patterns along with their conjunctions and disjunctions. The output of SPARQL queries can be results-sets or RDF graphs [18, 19].

E.g. Data in turtle format can be represented as below.

@prefix svestap: . _:a svestap:symptom "confusion and disorientation" . _:a svestap:symptom “memory loss” . _:b svestap:disease "Dimentia" . _:b svestap:symptom “palpitation” . _:c svestap:symptom “sweating”. _:b svestap:disease "Anxiety" .

Use following query to extract data

PREFIX svestap: SELECT ? disease ?symptom WHERE {

?x svestap:disease ?disease ?x svestap:symptom ?symptom

}

SPARQL uses “?” to define variables and SELECT clause define return ing variables as “?symptom” and “?disease” and WHERE clause define matching criteria. Fig. 7 illustrates sample query that retrieves disease by giving the set of symptoms. In here, there are four results sets fulfilling above criteria and following datasets are given as result set in Table 2.

Table 2. SPARQL Results set of matching criteria

Fig.7. SPARQL query to select disease from symptoms

During the conversation, the proposed expert system asks few questions from the patient and analyze patient’s responses to extract symptoms. From the NLU technique, symptoms were extracted and proceed to the next step of identifying disease category those symptoms belong to. Identify the exact disease based on the given symptoms is another key concern. This goal is accomplished in two stages as follows.

1.

First execute SPARQL queries separately for each

symptom and fetch all probable diseases for given symptom and categorize them as depicted in Fig. 8.

Fig.8. Sets of Diseases

E.g. Diseases ∈ {A, B, C, D} and Symptoms ∈ {X, Y, Z}, then diseases for symptoms are as follows,

Symptom X ∈ {Disease A, Disease B, Disease C}, Symptom Y ∈ {Disease C, Disease A, Disease D}, Symptom Z ∈ {Disease E, Disease C}.

2. Then find intersection of disease sets to find most

probable disease. Refer the Fig. 9 for interaction of diseases.

Symptom X ∩ Symptom Y = {Disease C},

Symptom X ∩ Symptom Z = {Disease C, Disease E}, Symptom Y ∩ Symptom Z = {Disease C},

Symptom X ∩ Symptom Y ∩ Symptom Z = {Disease C}.

Fig.9. Interaction of Diseases

If there is no disease which has all given symptoms, then proposed system get the disease with maximum number of matching diseases. Then the result will be passed to the NLG process to generate the response familiar to user.

D. Response Formation Using NLG Technique

Response formation is the final stage in the proposed system, after querying the knowledgebase (using SPARQL queries) the new inferred knowledge is given as set of keywords. To comprehend the final results, these keywords must be organized in a human-readable manner [20]. As depicted in Fig. 10, NLG process achieves this by converting keywords into human readable natural language sentences.

Fig.10. NLG Overview

Fig.11. Subprocess of NLG

NLG technique is implemented using Java language and separate library called “SimpleNLG” needs to be imported. This comprises inbuilt functions to accomplish the tasks depicted in Fig. 11 (Text planning, microplanning and realization) [22]. Sentence generation can be summarized as per the below three steps:

1. Develop a method to retrieve symptom keywords

from the knowledgebase.

2. Develop a method to include required words and

form meaningful phrases.

3. Develop a method to generate full sentence based

on small sentence-phrases using previously mentioned method.

To generate symptoms in question format for the user, separate xml document has been used to refer them as lexicons. The words in this xml document contains nouns, verbs, and complements (adjectives) refer Fig. 12. Then

keys are extracted from xml file using Xpath statements and “SimpleNLG” technique assists you to write a program which generates grammatically correct English sentences as illustrated in Fig. 13.

Fig.12. Lexicon keywords xml

Fig.13. Sentence Generation

After diagnosing the patient, the proposed system conducts a separate patient evaluation process to determine the intensity of the detected disease. This evaluation is performed by giving a Hypomania Checklist (HCL-32) standard questionnaire [21]. The intensity of the disease can be determined based on the

responses given for the questionnaire. In here, system acts as a separate human-counterpart and provides responses for the user’s questions.

IV. R ESULTS AND O UTCOME

This proposed system gives ten questions for the patient to answer and patient can answer them by using natural language sentences as shown in Fig. 14. The given response will be processed by the system and it elicits all symptoms from the response of patient to diagnose the disease. Then based on the given symptoms, it identifies the exact disease that patient is suffering from and formulate it as the response. The Fig. 15 represents, how it generates the response by inferring new knowledge.

Fig.14. Sample Q&A process with SVESTAP and Patient

Fig.15. Infer the disease based on symptoms

SVESTAP system was evaluated considering the factors such as understanding of the application, features included, usage of application, and willingness to use the application. From this evaluation positive and negative feedbacks were taken as illustrated in Table 3.

Table 3. User feedback summary

According to the chart depicted in Fig. 16 more than 80% of feedbacks were postive regarding the system usability and willingness to use the application is comparatively high.

Fig.16. User evaluation outcome of SVESTAP application

V. S UMMARY /C ONCLUSION

Nowadays the availability of experts to provide services symultaneously for multiple users would be a challenging task. To fullfill this problem, experimental analysis are conducted in many fields in developing similar virtual expert systems. Development of virtual experts would be an ideal solution but, validity of the made decision is questionable before applying them to real environment. Specially in medical domain, accuracy is the most decisive factor to be considered. As a result, development of expert system to assist real human expert would reduce upcoming risk in the medical domain. As the initial step, I would like to suggest a system that works with a real human expert, which maximizes accuracy factor of the made decision. Therefore, the decisions of disease judgement should always be aligned with actual psychiastrist and the end system response should be frequently evaluated. This system can be utilized for apprentices in the medical field to validate made disease judgement and to identify the root cause before proceeding for treatment.

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Authors’ Profiles

Udara Srimath S. Samaratunge

Arachchillage received the M.Sc. degree

in Enterprise Application Development

from Sheffield Hallam University (SHU) in

Sheffield, UK and won the best performer

award in 2014. He received his B.Sc.

Special honour degree in field of

Information Technology (IT) from Sri Lanka Institute of Information Technology (SLIIT) in Sri Lanka in 2010 and B.Sc. degree in IT from Curtin University of Technology, Bentley, Perth, Western Australia in 2009.

He is a Researcher, Lecturer and Software Engineer and currently works as Research Engineer in Department of Software Engineering, Institute of Cybernetics, National Research Tomsk Polytechnic University, Russia and Lecturer in Faculty of Computing, Department of Software Engineering, Sri Lanka Institute of Information Technology (SLIIT) in Sri Lanka. His research interests are Semantic Web, Expert System, Knowledgebase construction, Natural Language Processing, Software Engineering, Human Computer Interaction, Wireless Communication.

He is a member of Computing Society of Sri Lanka (CSSL) and manuscript reviewer in IEEE.

How to cite this paper:Udara Srimath S. Samaratunge Arachchillage, "Smart Virtual Expert System to Assist Psychiatrists (SVESTAP)", International Journal of Information Technology and Computer Science(IJITCS), Vol.10, No.1, pp.59-67, 2018. DOI: 10.5815/ijitcs.2018.01.07

《人工智能与专家系统》试卷

《人工智能与专家系统》试卷 (1)参考答案与评分标准 问答题(每题5分,共50分)1.人工智能是何时、何地、怎样诞生的?(5分)答:人工智能于1956年夏季在美国达特茅斯(Dartmouth)大学诞生。(3分)1956年夏季,美国的一些从事数学、心理学、计算机科学、信息论和神经学研究的年轻学者,汇聚在Dartmouth大学,举办了一次长达两个月的学术讨论会,认真而热烈地讨论了用机器模拟人类智能的问题。在这次会议上,第一次使用了“人工智能”这一术语,以代表有关机器智能这一研究方向。这是人类历史上第一次人工智能研讨会,标志着人工智能学科的诞生,具有十分重要的意义。(2分) 2.行为主义是人工智能的主要学派之一,它的基本观点是什么?(5分)答:行为主义,又称进化主义或控制论学派。这种观点认为智能取决于感知和行动(所以被称为行为主义),它不需要知识、不需要表示、不需要推理。其原理是控制论和感知——动作型控制系统。 3.什么是知识表示?在选择知识表示方法时,应该考虑哪几个因素?(5分)答:知识表示是研究用机器表示知识的可行性、有效性的般方法,是一种数据结构与控制结构的统一体,既考虑知识的存储又考虑知识的使用。知识表示实际上就是对人类知识的一种描述,以把人类知识表示成计算机能够处理的数据结构。对知识进行表示的过程就是把知识编码成某种数据结构的过程。

(3分) 在选择知识表示方法时,应该考虑以下几个因素:(1)能否充分表示相关的领域知识;(2)是否有利于对知识的利用;(3)是否便于知识的组织、维护和管理;(4)是否便于理解和实现。(2分)4.框架表示法有什么特点?(5分) 答:框架表示法有如下特点:结构性、继承性、自然性。(5分)5.何谓产生式系统?它由哪几部分组成?(5分) 答:把一组产生式放在一起,让它们相互配合,协同作用,一个产生式生成的结论可以供另一个产生式作为已知事实使用,以求得问题的解,这样的系统称为产生式系统。(2分) 产生式系统一般由三个基本部分组成:规则库、综合数据库和推理机。(3分)6.产生式系统中,推理机的推理方式有哪几种?请分别解释说明。(5分)答:产生式系统推理机的推理方式有正向推理、反向推理和双向推理三种。正向推理:正向推理是从己知事实出发,通过规则库求得结果。反向推理:反向推理是从目标出发,反向使用规则,求证已知的事实。双向推理:双向推理是既自顶向下又自底向上的推理。推理从两个方向进行,直至在某个中间界面上两方向结果相符便成功结束;如两方衔接不上,则推理失败。

人工智能与专家系统复习

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人工智能小型专家系统的设计与实现解读

人工智能技术基础实验报告 指导老师:朱力 任课教师:张勇

实验三小型专家系统设计与实现 一、实验目的 (1)增加学生对人工智能课程的兴趣; (2)使学生进一步理解并掌握人工智能prolog语言; (3)使学生加强对专家系统课程内容的理解和掌握,并培养学生综合运用所学知识开发智能系统的初步能力。 二、实验要求 (1)用产生式规则作为知识表示,用产生系统实现该专家系统。 (2)可使用本实验指导书中给出的示例程序,此时只需理解该程序,并增加自己感兴趣的修改即可;也可以参考该程序,然后用PROLOG语言或其他语言另行编写。 (3)程序运行时,应能在屏幕上显示程序运行结果。 三、实验环境 在Turbo PROLOG或Visual Prolog集成环境下调试运行简单的PROLOG程序。 四、实验内容 建造一个小型专家系统(如分类、诊断、预测等类型),具体应用领域由学生自选,具体系统名称由学生自定。 五、实验步骤 1、专家系统: 1.1建造一个完整的专家系统设计需完成的内容: 1.用户界面:可采用菜单方式或问答方式。

2.知识库(规则库):存放产生式规则,库中的规则可以增删。 3.数据库:用来存放用户回答的问题、已知事实、推理得到的中 间事实。 4.推理机:如何运用知识库中的规则进行问题的推理控制,建议 用正向推理。 5.知识库中的规则可以随意增减。 1.2推理策略 推理策略包括:正向(数据驱动),反向(目标驱动),双向 2、动物分类实验规则集 (1)若某动物有奶,则它是哺乳动物。 (2)若某动物有毛发,则它是哺乳动物。 (3)若某动物有羽毛,则它是鸟。 (4)若某动物会飞且生蛋,则它是鸟。 (5)若某动物是哺乳动物且有爪且有犬齿且目盯前方,则它是食肉动物。(6)若某动物是哺乳动物且吃肉,则它是食肉动物。 (7)若某动物是哺乳动物且有蹄,则它是有蹄动物。 (8)若某动物是有蹄动物且反刍食物,则它是偶蹄动物。 (9)若某动物是食肉动物且黄褐色且有黑色条纹,则它是老虎。 (10)若某动物是食肉动物且黄褐色且有黑色斑点,则它是猎豹。 (11)若某动物是有蹄动物且长腿且长脖子且黄褐色且有暗斑点,则它是长颈鹿。 (12)若某动物是有蹄动物且白色且有黑色条纹,则它是斑马。 (13)若某动物是鸟且不会飞且长腿且长脖子且黑白色,则它是驼鸟。

疾病诊断专家系统

目录 摘要............................................... 错误!未定义书签。Abstact............................................ 错误!未定义书签。第一章绪论........................................ 错误!未定义书签。 1.1引言........................................ 错误!未定义书签。 1.2问题的提出.................................. 错误!未定义书签。 1.3可行性分析.................................. 错误!未定义书签。 2.1专家系统概述................................ 错误!未定义书签。 2.1.1什么是专家系统........................ 错误!未定义书签。 2.1.2专家系统的组成........................ 错误!未定义书签。 2.1.3专家系统的应用领域.................... 错误!未定义书签。 2.2 知识库..................................... 错误!未定义书签。 2.3推理原理.................................... 错误!未定义书签。 2.3.1推理概念及分类........................ 错误!未定义书签。第三章鸡疾病诊断专家系统知识库的研究............. 错误!未定义书签。 3.1鸡疾病诊断专家系统介绍...................... 错误!未定义书签。 3.2鸡疾病诊断专家系统设计...................... 错误!未定义书签。 3.2.1系统功能.............................. 错误!未定义书签。 3.2.2 鸡疾病诊断专家系统知识开发的技术流程.. 错误!未定义书签。 3.2.3 鸡疾病诊断专家系统知识库的设计........... 错误!未定义书签。 3.3.1 知识表示.............................. 错误!未定义书签。第四章系统调试................................... 错误!未定义书签。 4.1 Prolog软件介绍............................. 错误!未定义书签。 4.1.1 Prolog语言的特征..................... 错误!未定义书签。 4.1.2 Prolog语言基本语句................... 错误!未定义书签。 4.2 程序调试................................... 错误!未定义书签。 4.2.1 推理机的概述.......................... 错误!未定义书签。 4.2.2 推理机的使用.......................... 错误!未定义书签。 4.2.2 调试结果.............................. 错误!未定义书签。第五章毕业设计小结................................ 错误!未定义书签。 5.1论文小结.................................... 错误!未定义书签。 5.2 知识库发展的趋势........................... 错误!未定义书签。致谢............................................... 错误!未定义书签。参考文献........................................... 错误!未定义书签。附录一源程序...................................... 错误!未定义书签。

鱼病诊断专家系统设计

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奶牛疾病诊断专家系统的设计说明

奶牛疾病诊断专家系统(人工智能期中作业) 学号:2007117019 班级:07级计科二班 姓名:陈青

奶牛疾病诊断专家系统 1.前言 专家系统是一个只能的计算机程序,它利用专家知识和经验解决领域难题。在过去的几十年发展中,专家系统已经成功地应用于各个领域,特别是疾病诊断领域专家系统的研究与应用更是呈现出蓬勃发展的景象,动物疾病诊断专家系统也位于其列。本文就奶牛疾病诊断专家系统的开发,对系统中的表示方法,知识库的监理方法,推理机的设计和实现以及推理过程作了全面的 阐述和讨论。2.正文 一、专家系统的任务与目标 1.奶牛疾病诊断知识的获取 2.奶牛疾病诊断专家系统推理机的研制 3.奶牛疾病诊断专家系统原型机实现 专家系统总体结构 二、专家系统的整体结构个部分:知识库、综合数据库、推理机、解释部分、专家系统基本结构一般包括以下6人机接口和知识获取机。(1) 用户界面统提供用户界面是用户同系统交流的通信机制。通过用户界面,用户选择系 的事实(问题的答案),回答系统提问,完成奶牛疾病诊断;查看相关资料和信息,进行有关知识咨询;系统为用户提供相关信息,进行有关知识咨询;系统为用户提供相关信息。 (2)解释机

基于规则的系统的一个最大特色就是具有解释功能,可以向用户解释系统为什么采用了一条规则,得出结论的依据是什么以及为什么向用户提问一定的问题等。 (3)推理机 推理机是系统根据用户提供的信息进行推理,最终得出结论的模块。 (4)其他数据库 该库由3个主要数据库组成。 动态数据库是系统在运行期间产生的一个临时数据库,用于存储用户提供的事实、系统激活的规则、系统产生的中间解以及系统中断的推理过程等。 多媒体数据库是为适应信息及其相关技术的迅速发展和应用而添加于专家系统中的辅助诊断信息库,它提供了与奶牛疾病诊断和治疗有关的图片、声音、影像和动画等资料。 防治措施库是存放防治措施和其他有关奶牛疾病相关的文字内容的数据库。 (5)知识库 该系统中采用了将事实库作为知识库的一部分的构造方法,因为奶牛疾病诊断知识的特殊性,把事实库中的事实作为界面上位用户提供的供选答案,因此,实时库中的所有事实都会在规则库中有完全匹配的规则,其实际作用相当与规则的前件。规则库是存放规则的所在。(6)知识编辑器 该系统采用了基于数据库的系统构建模式,系统中的知识库和所有数据库都是完全独立于系统的其他模块之外,知识编辑器是一个实施知识库的修改、删除、增加、检验的模块。 1.知识的获取与知识库的建立 奶牛疾病诊断知识的结构(1)对奶牛疾病诊断知识进行分析,并且完成对知识结构的划分,设计推理策略和建立知识库的前提条件。根据奶牛疾病诊断知识的特点,从3个方面对知识进行了从层次结构上的详尽描述。. ①以疾病为对象的分析 利用面向对象的思想,把对精兵的诊断知识进行面向对象的表示。 例如: 疾病=“炭疽”; 表现型数量=3; 表现型={最急性炭疽;急性炭疽;亚急性炭疽}; 表现性名称={急性炭疽}; 一般信息=“急性炭疽一般信息”; { 发病年龄=“犊牛成牛均发”; 发病季节=“夏秋季多发”; 饲喂方式=“放牧”; 放牧环境=“潮湿低洼地”; }; 症状=“急性炭疽症状” { 体温=“升高”; 精神=“兴奋不安、嚎叫或沉郁”; 呼吸=“呼吸促迫”; 可视粘膜变化=“发绀”; 食欲=“减退或停止”;

人工智能第六章_专家系统_的要点

1什么是专家系统。有什么特点和优点? 专家系统是一个具有大量的专门知识与经验的程序系统 专家系统是一种模拟人类专家解决领域问题的计算机程序系统特点: 启发性,能够运用专家的知识进行推理判断与决策 透明性,能够解释推理过程和回答用户问题 灵活性,能不断增长知识,更新知识库 专家系统的优点,自己课后了解一下。 2专家系统由哪些部分构成?各部分的作用? 知识库;综合数据库;推理机;解释器;接口 知识库,存储各领域专家的专门知识。静态。硬盘 综合数据库,存储初始问题数据和推理过程的中间数据。内存推理机,根据知识进行推理并导出结论。CPU 接口,用户界面,和用户进行交互。向用户提问,回答用户问题,并进行必要的解释。

知识获取机制是将专业知识转换成机器能理解的表达形式。 解释机制向用户解释以下问题:系统为什么要向用户提出该问题(Why)?计算机是如何得出最终结论的(How)? 3专家系统的分类,自己课下了解。 4建造专家系统的关键步骤。 专家系统团队关系图

是否拥有大量知识是专家系统成功与否的关键。因此知识表示是设计专家系统的关键 一.设计初始数据库 二.原型机的开发与实验 三.知识库的改进与归纳 建立专家系统的步骤图6.3P156页 5基于规则的专家系统

知识库:包含解决问题用到的领域知识,知识表达成为一序列规则。每个规则使用IF(条件)THEN(动作)结构指定的关系。当满足规则的条件部分时,便激发规则,执行动作部分。 数据库:包含一序列事实(一个对象及其取值构成了一个事实),所有的事实都存放在数据库中,用来和知识库中存储的规则的IF(条件)部分相匹配。 3. 基于规则的专家系统的推理机制 推理机制分为两大类:前向连接和后向链接 前向链接就是根据已有事实推断出新的事实。例如已知事实A is x,根据规则IF A is x THEN B is y。获得B is y。然后将B is y加入数据库。再寻找新的规则,即IF B is y THEN ….。

农作物病虫害诊断专家系统

农作物病虫害诊断专家系统 农业专家系统是农业信息技术中的一项重要技术、它是运用人工智能的专家系统技术,结合农业特点发展起来的一门高新技术。目前国际上的农业专家系统,广泛应用于作物生产管理、灌溉、施肥、品种选择、病虫害控制、温室昔理、家禽饲料配方、水上保持、食品加工、财务分析等许多方面。 1、专家系统体系结构 专家系统由知识库、知识的获取、推理机、综合数据库、解释程序、人机接口六个部分组成。 1.1知识库 知识库用以存放领域专家提供的专门知识、这此专门知识包括与领域相关的书木知识、常识性知识以及专家凭经验得到的试探性知识、专家系统的问题求解是运用专家提供的专门知识来模拟专家的思维方式进行的、知识库中拥有知识的数量和质量成为一个专家系统中系统性能和问题求解能力的关键因素。因此,知识库的建立是建造专家系统的中心任务。 1.2知识获取 知识获取部分负责对知识库进行昔理和维护,包括知识的输入、修改、删除和查询等昔理功能及知识的一致性、冗余性和完整性检查等维护功能。这些功能为领域专家提供了很大方便,使得他们不必知道知识库中的知识表示形式即可建立知识库并对其进行修改和扩充,大大提高了系统的可扩充性。 1.3推理机 推理机是专家系统的思维机构,是构成专家系统的核心部分,因为推理是专家系统解决问题的基木技术。它能够根据当前已知的事实利用知识库中的知识按一定的推理方法和控制策略进行推理求得问

题的解答或证明某个假设的正确性;在一定的控制策略下针对综合数据库中的当前信息,识别和选取知识库中对当前问题求解有用的知识进行推理。 1.4综合数据库 主要存放与专家系统推理相关的数据,包括用户输入的信息、推理过程产生的新信息以及推理所得到的结了等。 1.5解释程序 解释机由一组程序组成,跟踪并记录推理过程,当用户提出“为引一么?”“结论是如何得出的?”等询问需要解释时,它将根据问题的要求分别做出相应的处理,最后把解答用约定的形式通过用户界面输出给用户,便于用户理解系统的问题求解,增加用户对求解结果的信任程度、在知识库的完善过程中便于专家或知识工程师发现和定位知识库中的错误,便于领域的专业人员或初学者能够从问题的求解过程中得到直观学习。 1.6人机接口 人机接口是专家系统与用户的接口,用于完成输入输出工作。领域专家或知识工程师通过它输入知识、更新、完善知识库;一般用户通过它查询欲求解的问题以及向用户索取更多的事实。它可以将专家或用户的输入信息翻译为系统可接受的内部形式,把系统向专家或用户输出的信息转换成人类易于理解的外部形式。 2、农作物病虫害诊断专家系统设计 2.1知识获取 知识的获取分为两大类:一是应用领域的基木原理和常识;二是领域专家求解问题的经验知识。前者构成专门知识的主部,可以精确地定义和使用。这类知识尽昔是求解问题的基础,但并不与求解的问题紧密结合,加之知识量大和推理步小,不能高效地支持问题求解。

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