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Neuro-Knowledge-Based Expert System (NKBES) for Optimal Scheming of Die Casting Process
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作者 QiaodanHU PengLUO +1 位作者 YiYANG LiliangCHEN 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第5期622-626,共5页
We develop a neuro-knowledge-based expert system (NKBES) frame in this work. The system mainly concerns with decision of gating system and die casting machine based on a neuro-inference engine launched under the MATLA... We develop a neuro-knowledge-based expert system (NKBES) frame in this work. The system mainly concerns with decision of gating system and die casting machine based on a neuro-inference engine launched under the MATLAB software environment. For enhancement of reasoning agility, an error back-propagation neural network was applied. A rapidly convergent adaptive learning rate (ALR) and a momentum-based error back-propagation algorithm was used to conduct neuro-reasoning. The working effect of the system was compared to a conventional expert system that is based on a two-way (forward and backward) chaining inference mechanism. As the reference, the present paper provided the neural networks sum-squared error (S5E) and ALR vs iterative epoch curves of process planning case mentioned above. The study suggests that the neuro-modeling optimization application to die casting process design has good feasibility, and based on that a novel and effective intelligent expert system can be launched at low cost. 展开更多
关键词 Die casting Neuro-knowledge-based expert system Process planning
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Metacognition Inspired Reflective Chain-of-Thought for Knowledge-Based VQA
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作者 Zhongfan Sun Kan Guo +1 位作者 Yongli Hu Yong Zhang 《Computers, Materials & Continua》 2026年第4期1909-1933,共25页
Knowledge-based VisualQuestion Answering(VQA)requires the integration of visual information with external knowledge reasoning.Existing approaches typically retrieve information from external corpora and rely on pretra... Knowledge-based VisualQuestion Answering(VQA)requires the integration of visual information with external knowledge reasoning.Existing approaches typically retrieve information from external corpora and rely on pretrained language models for reasoning.However,their performance is often hindered by the limited capabilities of retrievers and the constrained size of knowledge bases.Moreover,relying on image captions to bridge the modal gap between visual and language modalities can lead to the omission of critical visual details.To address these limitations,we propose the Reflective Chain-of-Thought(ReCoT)method,a simple yet effective framework inspired by metacognition theory.ReCoT effectively activates the reasoning capabilities ofMultimodal Large LanguageModels(MLLMs),providing essential visual and knowledge cues required to solve complex visual questions.It simulates a metacognitive reasoning process that encompasses monitoring,reflection,and correction.Specifically,in the initial generation stage,an MLLM produces a preliminary answer that serves as the model’s initial cognitive output.During the reflective reasoning stage,this answer is critically examined to generate a reflective rationale that integrates key visual evidence and relevant knowledge.In the final refinement stage,a smaller language model leverages this rationale to revise the initial prediction,resulting in amore accurate final answer.By harnessing the strengths ofMLLMs in visual and knowledge grounding,ReCoT enables smaller language models to reason effectively without dependence on image captions or external knowledge bases.Experimental results demonstrate that ReCoT achieves substantial performance improvements,outperforming state-of-the-art methods by 2.26%on OK-VQA and 5.8%on A-OKVQA. 展开更多
关键词 knowledge-based VQA METACOGNITION reflective chain-of-thought answer refinement
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Expert Knowledge-Based Apparel Recommendation Question and Answer System 被引量:1
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作者 LIU Xun SHI Youqun +1 位作者 LUO Xin ZHU Guoxue 《Journal of Donghua University(English Edition)》 CAS 2022年第1期55-64,共10页
Aiming at the lack of professional knowledge to guide apparel recommendation,an apparel recommendation method based on image design expert knowledge has been proposed.Then,apparel recommendation knowledge graphs have ... Aiming at the lack of professional knowledge to guide apparel recommendation,an apparel recommendation method based on image design expert knowledge has been proposed.Then,apparel recommendation knowledge graphs have been created and a apparel recommendation question and answer(Q&A)system has been designed and implemented.The question templates in the apparel recommendation domain were defined,the task of recognizing the named entities of question sentences was completed by the Bi-directional encoder representations from transformer-Bi-directional long short-term memory-conditional random field(BERT-BiLSTM-CRF)model,and the question template with the highest matching degree to the user’s question was obtained by using term frequency-inverse document frequency(TF-IDF)algorithm.The corresponding cypher graph database query statement was generated to retrieve the knowledge graph for answers,and iFLYTEK’s voice application programming interface(API)was called to implement the Q&A.The experimental results have shown that the Q&A system has a high accuracy rate and application value in the field of apparel recommendations. 展开更多
关键词 expert knowledge apparel recommendation knowledge graph question and answer(Q&A)system speech recognition
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A physics knowledge-based surrogate model framework for timedependent slope deformation:Considering water effect and sliding states
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作者 Wenyu Zhuang Yaoru Liu +3 位作者 Kai Zhang Qingchao Lyu Shaokang Hou Qiang Yang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第9期5416-5436,共21页
The surrogate model serves as an efficient simulation tool during the slope parameter inversion process.However,the creep constitutive model integrated with dynamic damage evolution poses challenges in development of ... The surrogate model serves as an efficient simulation tool during the slope parameter inversion process.However,the creep constitutive model integrated with dynamic damage evolution poses challenges in development of the required surrogate model.In this study,a novel physics knowledge-based surrogate model framework is proposed.In this framework,a Transformer module is employed to capture straindriven softening-hardening physical mechanisms.Positional encoding and self-attention are utilized to transform the constitutive parameters associated with shear strain,which are not directly time-related,into intermediate latent features for physical loss calculation.Next,a multi-layer stacked GRU(gated recurrent unit)network is built to provide input interfaces for time-dependent intermediate latent features,hydraulic boundary conditions,and water-rock interaction degradation equations,with static parameters introduced via external fully-connected layers.Finally,a combined loss function is constructed to facilitate the collaborative training of physical and data loss,introducing time-dependent weight adjustments to focus the surrogate model on accurate deformation predictions during critical phases.Based on the deformation of a reservoir bank landslide triggered by impoundment and subsequent restabilization,an elasto-viscoplastic constitutive model that considers water effect and sliding state dependencies is developed to validate the proposed surrogate model framework.The results indicate that the framework exhibits good performance in capturing physical mechanisms and predicting creep behavior,reducing errors by about 30 times compared to baseline models such as GRU and LSTM(long short-term memory),meeting the precision requirements for parameter inversion.Ablation experiments also confirmed the effectiveness of the framework.This framework can also serve as a reference for constructing other creep surrogate models that involve non-time-related across dimensions. 展开更多
关键词 Reservoir bank slope Time-dependent deformation Elasto-viscoplastic constitutive model Physics knowledge-based deep learning Surrogate model
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基于Design-Expert和离散元仿真的草坪修剪机刀具的设计与参数优化
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作者 刘舰泽 马晓春 赵佳硕 《林产工业》 北大核心 2026年第2期23-30,共8页
针对传统草坪修剪机刀具切割阻力大、磨损快的问题,以滑切角、刃倾角和刀具转速为设计变量,采用Design-Expert和EDEM仿真对草坪修剪机刀具进行参数优化。首先,提出了一种基于对数螺线原理的等滑切角刀具设计方法,确定滑切角、刃倾角和... 针对传统草坪修剪机刀具切割阻力大、磨损快的问题,以滑切角、刃倾角和刀具转速为设计变量,采用Design-Expert和EDEM仿真对草坪修剪机刀具进行参数优化。首先,提出了一种基于对数螺线原理的等滑切角刀具设计方法,确定滑切角、刃倾角和刀具的转速范围。其次,利用EDEM软件构建了生草模型和刀具模型,并进行仿真切割,得到了刀具的受力数据。最后,通过Design-Expert软件进行了三水平三因素正交试验设计,以刀具所受法向力和切向力为评价标准,对试验结果进行方差分析、显著性检验和响应曲面分析,建立了二次回归模型,并进行多目标参数优化。结果表明:当滑切角为42.8°,刃倾角为35.4°,刀具转速为1416 r/min时,刀具所受的法向力和切向力最小。研究结果为刀具的设计和优化提供了理论依据。 展开更多
关键词 等滑切角 刀具转速 刃倾角 EDEM Design-expert
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Can Domain Knowledge Make Deep Models Smarter?Expert-Guided PointPillar(EG-PointPillar)for Enhanced 3D Object Detection
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作者 Chiwan Ahn Daehee Kim Seongkeun Park 《Computers, Materials & Continua》 2026年第4期2022-2048,共27页
This paper proposes a deep learning-based 3D LiDAR perception framework designed for applications such as autonomous robots and vehicles.To address the high dependency on large-scale annotated data—an inherent limita... This paper proposes a deep learning-based 3D LiDAR perception framework designed for applications such as autonomous robots and vehicles.To address the high dependency on large-scale annotated data—an inherent limitation of deep learning models—this study introduces a hybrid perception architecture that incorporates expertdriven LiDAR processing techniques into the deep neural network.Traditional 3DLiDAR processingmethods typically remove ground planes and apply distance-or density-based clustering for object detection.In this work,such expert knowledge is encoded as feature-level inputs and fused with the deep network,therebymitigating the data dependency issue of conventional learning-based approaches.Specifically,the proposedmethod combines two expert algorithms—Patchwork++for ground segmentation and DBSCAN for clustering—with a PointPillars-based LiDAR detection network.We design four hybrid versions of the network depending on the stage and method of integrating expert features into the feature map of the deep model.Among these,Version 4 incorporates a modified neck structure in PointPillars and introduces a new Cluster 2D Pseudo-Map Branch that utilizes cluster-level pseudo-images generated from Patchwork++and DBSCAN.This version achieved a+3.88%improvement mean Average Precision(mAP)compared to the baseline PointPillars.The results demonstrate that embedding expert-based perception logic into deep neural architectures can effectively enhance performance and reduce dependency on extensive training datasets,offering a promising direction for robust 3D LiDAR object detection in real-world scenarios. 展开更多
关键词 LIDAR PointPillar expert knowledge autonomous driving deep learning
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Improved expert system of rockburst intensity level prediction based on machine learning and data-driven:Supported by 1114 rockburst cases in 197 rock underground projects
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作者 PANG Hong-li GONG Feng-qiang +1 位作者 GAO Ming-zhong DAI Jin-hao 《Journal of Central South University》 2026年第1期335-356,共22页
Accurate prediction of rockburst intensity levels is crucial for ensuring the safety of deep hard rock engineering construction.This paper introduced an expert system for rockburst intensity level prediction that empl... Accurate prediction of rockburst intensity levels is crucial for ensuring the safety of deep hard rock engineering construction.This paper introduced an expert system for rockburst intensity level prediction that employs machine learning algorithms as the basis for its inference rules.The system comprises four modules:a database,a repository,an inference engine,and an interpreter.A database containing 1114 rockburst cases was used to construct 357 datasets that serve as the repository for the expert system.Additionally,19 types of machine learning algorithms were used to establish 6783 micro-models to construct cognitive rules within the inference engine.By integrating probability theory and marginal analysis,a fuzzy scoring method based on the SoftMax function was developed and applied to the interpreter for rockburst intensity level prediction,effectively restoring the continuity of rockburst characteristics.The research results indicate that ensemble algorithms based on decision trees are more effective in capturing the characteristics of rockburst.Key factors for accurate prediction of rockburst intensity include uniaxial compressive strength,elastic energy index,the maximum principal stress,tangential stress,and their composite indicators.The accuracy of the proposed rockburst intensity level prediction expert system was verified using 20 engineering rockburst cases,with predictions aligning closely with the actual rockburst intensity levels. 展开更多
关键词 rock mechanics ROCKBURST rockburst intensity level prediction expert system machine learning supervised learning
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Collaborative Approaches to Poverty Reduction:Experts and o"cials from China and abroad exchange views on cooperation and sustainable development at seminar
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作者 LU JIAJUN 《ChinAfrica》 2026年第2期34-35,共2页
The 17 Sustainable Development Goals(SDGs)for 2030,adopted by all United Nations member states in 2015,are facing a range of challenges.Factors such as climate change,regional conflicts and economic recession are havi... The 17 Sustainable Development Goals(SDGs)for 2030,adopted by all United Nations member states in 2015,are facing a range of challenges.Factors such as climate change,regional conflicts and economic recession are having a significant impact,particularly on global poverty governance.As a platform for dialogue,exchange and technical cooperation,the 2025 International Seminar on Global Poverty Reduction Partnerships was held in Beijing on 10 December 2025. 展开更多
关键词 climate changeregional conflicts collaborative approaches China global poverty reduction OFFICIALS sustainable development goals sdgs economic recession experts
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Knowledge-Based Classification in Automated Soil Mapping 被引量:10
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作者 ZHOU BIN and WANG RENCHAOInstitute of Agricultural Remote Sensing and Information Technology Application, Zhejiang University, Hangzhou 310029 (China) 《Pedosphere》 SCIE CAS CSCD 2003年第3期209-218,共10页
A machine-learning approach was developed for automated building of knowledgebases for soil resources mapping by using a classification tree to generate knowledge from trainingdata. With this method, building a knowle... A machine-learning approach was developed for automated building of knowledgebases for soil resources mapping by using a classification tree to generate knowledge from trainingdata. With this method, building a knowledge base for automated soil mapping was easier than usingthe conventional knowledge acquisition approach. The knowledge base built by classification tree wasused by the knowledge classifier to perform the soil type classification of Longyou County,Zhejiang Province, China using Landsat TM bi-temporal images and CIS data. To evaluate theperformance of the resultant knowledge bases, the classification results were compared to existingsoil map based on a field survey. The accuracy assessment and analysis of the resultant soil mapssuggested that the knowledge bases built by the machine-learning method was of good quality formapping distribution model of soil classes over the study area. 展开更多
关键词 CLASSIFICATION classification tree knowledge-based rule extracting soilmapping
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Knowledge-based bridge detection from SAR images 被引量:5
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作者 Wang Wenguang Sun Jinping +1 位作者 Hu Rui Mao Shiyi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第5期929-936,共8页
Automatic bridge detection is an important application of SAR images.Differed from the classical CFAR method,a new knowledge-based bridge detection approach is proposed.The method not only uses the backscattering inte... Automatic bridge detection is an important application of SAR images.Differed from the classical CFAR method,a new knowledge-based bridge detection approach is proposed.The method not only uses the backscattering intensity difference between targets and background but also applies the contextual information and spatial relationship between objects.According to bridges'special characteristics and scattering properties in SAR images,the new knowledge-based method includes three processes:river segmentation,potential bridge areas detection and bridge discrimination.The application to AIRSAR data shows that the new method is not sensitive to rivers'shape.Moreover,this method can detect bridges successfully when river segmentation is not very exact and is more robust than the radius projection method. 展开更多
关键词 knowledge-based bridge detection SAR contextual information mathematical morphology.
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New Knowledge-based Genetic Algorithm for Excavator Boom Structural Optimization 被引量:6
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作者 HUA Haiyan LIN Shuwen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第2期392-401,共10页
Due to the insufficiency of utilizing knowledge to guide the complex optimal searching, existing genetic algorithms fail to effectively solve excavator boom structural optimization problem. To improve the optimization... Due to the insufficiency of utilizing knowledge to guide the complex optimal searching, existing genetic algorithms fail to effectively solve excavator boom structural optimization problem. To improve the optimization efficiency and quality, a new knowledge-based real-coded genetic algorithm is proposed. A dual evolution mechanism combining knowledge evolution with genetic algorithm is established to extract, handle and utilize the shallow and deep implicit constraint knowledge to guide the optimal searching of genetic algorithm circularly. Based on this dual evolution mechanism, knowledge evolution and population evolution can be connected by knowledge influence operators to improve the conflgurability of knowledge and genetic operators. Then, the new knowledge-based selection operator, crossover operator and mutation operator are proposed to integrate the optimal process knowledge and domain culture to guide the excavator boom structural optimization. Eight kinds of testing algorithms, which include different genetic operators, arc taken as examples to solve the structural optimization of a medium-sized excavator boom. By comparing the results of optimization, it is shown that the algorithm including all the new knowledge-based genetic operators can more remarkably improve the evolutionary rate and searching ability than other testing algorithms, which demonstrates the effectiveness of knowledge for guiding optimal searching. The proposed knowledge-based genetic algorithm by combining multi-level knowledge evolution with numerical optimization provides a new effective method for solving the complex engineering optimization problem. 展开更多
关键词 boom structural optimization dual evolution mechanism knowledge-based genetic strategies deep implicit knowledge domain culture
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Structural Topology Design of Container Ship Based on Knowledge-Based Engineering and Level Set Method 被引量:5
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作者 崔进举 王德禹 史琪琪 《China Ocean Engineering》 SCIE EI CSCD 2015年第4期551-564,共14页
Knowledge-Based Engineering (KBE) is introduced into the ship structural design in this paper. From the implementation of KBE, the design solutions for both Rules Design Method (RDM) and Interpolation Design Meth... Knowledge-Based Engineering (KBE) is introduced into the ship structural design in this paper. From the implementation of KBE, the design solutions for both Rules Design Method (RDM) and Interpolation Design Method (IDM) are generated. The corresponding Finite Element (FE) models are generated. Topological design of the longitudinal structures is studied where the Gaussian Process (GP) is employed to build the surrogate model for FE analysis. Multi-objective optimization methods inspired by Pareto Front are used to reduce the design tank weight and outer surface area simultaneously. Additionally, an enhanced Level Set Method (LSM) which employs implicit algorithm is applied to the topological design of typical bracket plate which is used extensively in ship structures. Two different sets of boundary conditions are considered. The proposed methods show satisfactory efficiency and accuracy. 展开更多
关键词 knowledge-based Engineering (KBE) Level Set Method (LSM) Gaussian Process GP)
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FAULT DIAGNOSIS OF ROTATING MACHINERY USING KNOWLEDGE-BASED FUZZY NEURAL NETWORK 被引量:2
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作者 李如强 陈进 伍星 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第1期99-108,共10页
A novel knowledge-based fuzzy neural network (KBFNN) for fault diagnosis is presented. Crude rules were extracted and the corresponding dependent factors and antecedent coverage factors were calculated firstly from ... A novel knowledge-based fuzzy neural network (KBFNN) for fault diagnosis is presented. Crude rules were extracted and the corresponding dependent factors and antecedent coverage factors were calculated firstly from the diagnostic sample based on rough sets theory. Then the number of rules was used to construct partially the structure of a fuzzy neural network and those factors were implemented as initial weights, with fuzzy output parameters being optimized by genetic algorithm. Such fuzzy neural network was called KBFNN. This KBFNN was utilized to identify typical faults of rotating machinery. Diagnostic results show that it has those merits of shorter training time and higher right diagnostic level compared to general fuzzy neural networks. 展开更多
关键词 rotating machinery fault diagnosis rough sets theory fuzzy sets theory generic algorithm knowledge-based fuzzy neural network
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Knowledge-based potentials in bioinformatics: From a physicist's viewpoint 被引量:1
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作者 郑伟谋 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第12期22-27,共6页
Biological raw data are growing exponentially, providing a large amount of information on what life is. It is believed that potential functions and the rules governing protein behaviors can be revealed from analysis o... Biological raw data are growing exponentially, providing a large amount of information on what life is. It is believed that potential functions and the rules governing protein behaviors can be revealed from analysis on known native structures of proteins. Many knowledge-based potentials for proteins have been proposed. Contrary to most existing review articles which mainly describe technical details and applications of various potential models, the main foci for the discussion here are ideas and concepts involving the construction of potentials, including the relation between free energy and energy, the additivity of potentials of mean force and some key issues in potential construction. Sequence analysis is briefly viewed from an energetic viewpoint. 展开更多
关键词 knowledge-based potentials for proteins protein native structures sequence signals
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A Knowledge-based System for the Analysis of the Ability of Paying back Loans 被引量:1
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作者 Zhu Ming(朱明) +1 位作者 Yang Baoan(杨保安) 《Journal of Donghua University(English Edition)》 EI CAS 2001年第1期123-126,共4页
This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system deve... This paper describes the development of a knowledgebased system (KBS) for determining whether or not, and under what conditions, a bank Ioan officer should grant a business loan to a company. The prototype system developed focuses on what is bank loans risks management, how to prevent risk by the analysis of the ability of paying back loans. The paper makes the structural analysis involved in the system's decision situation, the structured situation diagram or model, dependency diagram and the document needed by the KBS prototype system thus are developed. Through testing the samples from loan business, the quality for the analysis of the ability of paying back loans can be effectively evaluated by the KBS prototype system. 展开更多
关键词 knowledge-based SYSTEM (KBS) the KBS prototype system the ABILITY of paying BACK loans bank LOANS risk management.
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Integration of Decision-Support and Knowledge-Based Techniques in a Problem-Solving Strategy for Selection Problems 被引量:1
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作者 David McSherry(School of Information and Software Engineering,Faculty of Informatics, University of Ulster,Coleraine BT52 1SA, Northern Ireland) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1996年第2期35-54,共20页
The limitations of traditional approaches to selection problems are examined. A problemsolving strategy is presented in which decision-support and knowledge-based techniques play complementary roles. An approach to th... The limitations of traditional approaches to selection problems are examined. A problemsolving strategy is presented in which decision-support and knowledge-based techniques play complementary roles. An approach to the representation of knowledge to support the problem-solving strategy is presented which avoids commitment to a specific programming language or implementation environment. The problem of choosing a home is used to illustrate the representation of knowledge in a specific problem domain. Techniques for implementation of the problem-solving strategy are described. Knowledge elicitation techniques and their implementation in a development shell for application of the problem-solving strategy to any selection problem are also described. 展开更多
关键词 knowledge-based systems Decision-support systems Knowledge acquisition Multiple criteria decision making Operational research Analytic hierarchy process
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Yarn Quality Prediction and Diagnosis Based on Rough Set and Knowledge-Based Artificial Neural Network 被引量:1
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作者 杨建国 徐兰 +1 位作者 项前 刘彬 《Journal of Donghua University(English Edition)》 EI CAS 2014年第6期817-823,共7页
In the spinning process, some key process parameters( i. e.,raw material index inputs) have very strong relationship with the quality of finished products. The abnormal changes of these process parameters could result... In the spinning process, some key process parameters( i. e.,raw material index inputs) have very strong relationship with the quality of finished products. The abnormal changes of these process parameters could result in various categories of faulty products. In this paper, a hybrid learning-based model was developed for on-line intelligent monitoring and diagnosis of the spinning process. In the proposed model, a knowledge-based artificial neural network( KBANN) was developed for monitoring the spinning process and recognizing faulty quality categories of yarn. In addition,a rough set( RS)-based rule extraction approach named RSRule was developed to discover the causal relationship between textile parameters and yarn quality. These extracted rules were applied in diagnosis of the spinning process, provided guidelines on improving yarn quality,and were used to construct KBANN. Experiments show that the proposed model significantly improve the learning efficiency, and its prediction precision is improved by about 5. 4% compared with the BP neural network model. 展开更多
关键词 yarn quality prediction rough set(RS) knowledge discovery knowledge-based artificial neural network(KBANN)
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MY PERSONAL STUDY ON KNOWLEDGE-BASED ECONOMY 被引量:2
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作者 Deng Shuhui(Institute of Systems Science, the CAS) 《Bulletin of the Chinese Academy of Sciences》 1999年第2期119-120,共2页
The Financial Crisis in Asia is having a negative impacion the economic development of China, but it also enlightens us. It makes us consider and take measures to avoid such a crisis. I have put forward six measures, ... The Financial Crisis in Asia is having a negative impacion the economic development of China, but it also enlightens us. It makes us consider and take measures to avoid such a crisis. I have put forward six measures, one of which is to promote the transformation of S&T knowledge into productive forces. 展开更多
关键词 MODE MY PERSONAL STUDY ON knowledge-based ECONOMY
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Research on Knowledge-based Connecting Elements Modeling
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作者 HUANG Xiang, YAN Chong-jing (College of Mechanical and Electrical Engineering, Nanjing University o f Aeronautics and Astronautics, Nanjing 210016, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期162-163,共2页
Steps of manipulation is required to complete the m od eling of the connection elements such as bolt, pin and the like in commerce CAD system. It leads to low efficiency, difficulty to assure the relative position, im... Steps of manipulation is required to complete the m od eling of the connection elements such as bolt, pin and the like in commerce CAD system. It leads to low efficiency, difficulty to assure the relative position, impossibility to express rules and knowledge. Based on the inner character analy sis of interpart, detail modification and assembly relation of mechanical connec ting element, the idea, which extends the feature modeling of part to the interp art feature modeling for assembly purpose, is presented, and virtual part based connecting element modeling is proposed. Virtual part is a complement set of lo cal modification of part to be connected. In assembly modeling, base part is mod ified by Boolean operation between base part and virtual part. The modeling and assembly is finished just in one operation, at the same time the rules and knowl edge of the connection elements are encapsulated through virtual part. According to this mechanism, a knowledge-based connecting elements rapid design module i s developed on commerce software package UG with satisfying results. 展开更多
关键词 CAD knowledge-based engineering ASSEMBLY conn ecting element
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Optimizing the atom types of proteins through iterative knowledge-based potentials
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作者 汪心享 黄胜友 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期43-50,共8页
Knowledge-based scoring functions have been widely used for protein structure prediction, protein-small molecule, and protein-nucleic acid interactions, in which one critical step is to find an appropriate representat... Knowledge-based scoring functions have been widely used for protein structure prediction, protein-small molecule, and protein-nucleic acid interactions, in which one critical step is to find an appropriate representation of protein structures. A key issue is to determine the minimal protein representations, which is important not only for developing of scoring func- tions but also for understanding the physics of protein folding. Despite significant progresses in simplifying residues into alphabets, few studies have been done to address the optimal number of atom types for proteins. Here, we have investigated the atom typing issue by classifying the 167 heavy atoms of proteins through 11 schemes with 1 to 20 atom types based on their physicochemical and functional environments. For each atom typing scheme, a statistical mechanics-based iterative method was used to extract atomic distance-dependent potentials from protein structures. The atomic distance-dependent pair potentials for different schemes were illustrated by several typical atom pairs with different physicochemical proper- ties. The derived potentials were also evaluated on a high-resolution test set of 148 diverse proteins for native structure recognition. It was found that there was a crossover around the scheme of four atom types in terms of the success rate as a function of the number of atom types, which means that four atom types may be used when investigating the basic folding mechanism of proteins. However, it was revealed by a close examination of typical potentials that 14 atom types were needed to describe the protein interactions at atomic level. The present study will be beneficial for the development of protein related scoring functions and the understanding of folding mechanisms. 展开更多
关键词 atom types knowledge-based potentials statistical mechanics ITERATION
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