• Title/Summary/Keyword: Rule-based approach

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A Real-Time Stock Market Prediction Using Knowledge Accumulation (지식 누적을 이용한 실시간 주식시장 예측)

  • Kim, Jin-Hwa;Hong, Kwang-Hun;Min, Jin-Young
    • Journal of Intelligence and Information Systems
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    • v.17 no.4
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    • pp.109-130
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    • 2011
  • One of the major problems in the area of data mining is the size of the data, as most data set has huge volume these days. Streams of data are normally accumulated into data storages or databases. Transactions in internet, mobile devices and ubiquitous environment produce streams of data continuously. Some data set are just buried un-used inside huge data storage due to its huge size. Some data set is quickly lost as soon as it is created as it is not saved due to many reasons. How to use this large size data and to use data on stream efficiently are challenging questions in the study of data mining. Stream data is a data set that is accumulated to the data storage from a data source continuously. The size of this data set, in many cases, becomes increasingly large over time. To mine information from this massive data, it takes too many resources such as storage, money and time. These unique characteristics of the stream data make it difficult and expensive to store all the stream data sets accumulated over time. Otherwise, if one uses only recent or partial of data to mine information or pattern, there can be losses of valuable information, which can be useful. To avoid these problems, this study suggests a method efficiently accumulates information or patterns in the form of rule set over time. A rule set is mined from a data set in stream and this rule set is accumulated into a master rule set storage, which is also a model for real-time decision making. One of the main advantages of this method is that it takes much smaller storage space compared to the traditional method, which saves the whole data set. Another advantage of using this method is that the accumulated rule set is used as a prediction model. Prompt response to the request from users is possible anytime as the rule set is ready anytime to be used to make decisions. This makes real-time decision making possible, which is the greatest advantage of this method. Based on theories of ensemble approaches, combination of many different models can produce better prediction model in performance. The consolidated rule set actually covers all the data set while the traditional sampling approach only covers part of the whole data set. This study uses a stock market data that has a heterogeneous data set as the characteristic of data varies over time. The indexes in stock market data can fluctuate in different situations whenever there is an event influencing the stock market index. Therefore the variance of the values in each variable is large compared to that of the homogeneous data set. Prediction with heterogeneous data set is naturally much more difficult, compared to that of homogeneous data set as it is more difficult to predict in unpredictable situation. This study tests two general mining approaches and compare prediction performances of these two suggested methods with the method we suggest in this study. The first approach is inducing a rule set from the recent data set to predict new data set. The seocnd one is inducing a rule set from all the data which have been accumulated from the beginning every time one has to predict new data set. We found neither of these two is as good as the method of accumulated rule set in its performance. Furthermore, the study shows experiments with different prediction models. The first approach is building a prediction model only with more important rule sets and the second approach is the method using all the rule sets by assigning weights on the rules based on their performance. The second approach shows better performance compared to the first one. The experiments also show that the suggested method in this study can be an efficient approach for mining information and pattern with stream data. This method has a limitation of bounding its application to stock market data. More dynamic real-time steam data set is desirable for the application of this method. There is also another problem in this study. When the number of rules is increasing over time, it has to manage special rules such as redundant rules or conflicting rules efficiently.

A Symbolic Layout Generator for CMOS Standard Cells Using Artificial Intelligence Approach (인공지능 기법을 이용한 CMOS 표준셀의 심볼릭 레이아웃 발생기)

  • 유종근;이문기
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.6
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    • pp.1080-1086
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    • 1987
  • SLAGEN, a system for symbolic cell layout based on artificial intelligence approach, takes as input a transistor connection description of CMOS standard cells and environment information, and outputs a symbolic layout description. SLAGEN performas transistor grouping by a heuristic search method, in order to minimize the number of separations, and then performs group reordering and transistor reordering with an eye toward minimizing routing. Next, SLAGEN creates a rough initial routing in order to guarantee functionality and correctness, and then improve the initial routing by a rule-based approach.

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A Software Quality Assurance Methodology and a Direction for Its Usage (SQA 활동 지원을 위한 방법론 및 그 활용방향)

  • 김성근;편완주
    • The Journal of Information Technology and Database
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    • v.7 no.1
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    • pp.113-130
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    • 2000
  • As software projects become larger and more complex, we need to take a more systematic approach to quality assurance. One plausible approach is the use of SQA (software quality assurance) methodology. Since this SQA methodology was not available, our study presents a SQA methodology. This methodology has a repository in which a set of quality assurance tasks with their related techniques and deliverables is defined and from which one can select only appropriate tasks based upon characteristics of project. This study further suggests a rule-based approach for supporting task selection process.

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Development of Rule-Based Malicious URL Detection Library Considering User Experiences (사용자 경험을 고려한 규칙기반 악성 URL 탐지 라이브러리 개발)

  • Kim, Bo-Min;Han, Ye-Won;Kim, Ga-Young;Kim, Ye-Bun;Kim, Hyung-Jong
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.30 no.3
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    • pp.481-491
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    • 2020
  • The malicious URLs which can be used for sending malicious codes and illegally acquiring private information is one of the biggest threat of information security field. Particularly, recent prevalence of smart-phone increases the possibility of the user's exposing to malicious URLs. Since the way of hiding the URL from the user is getting more sophisticated, it is getting harder to detect it. In this paper, after conducting a survey of the user experiences related to malicious URLs, we are proposing the rule-based malicious URL detection method. In addition, we have developed java library which can be applied to any other applications which need to handle the malicious URL. Each class of the library is implementation of a rule for detecting a characteristics of a malicious URL and the library itself is the set of rule which can have the chain of rule for deteciing more complicated situation and enhancing the accuracy. This kinds of rule based approach can enhance the extensibility considering the diversity of malicious URLs.

Optimizing dispatching strategy based on multicriteria heuristics for AGVs in automated container terminal (자동화 컨테이너 터미널의 복수 규칙 기반 AGV 배차 전략 최적화)

  • Kim, Jeong-Min;Choe, Ri;Park, Tae-Jin;Ryu, Kwang-Ryul
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2011.06a
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    • pp.218-219
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    • 2011
  • This paper focuses on dispatching strategy for AGVs(Automated Guided Vehicle). The goal of AGV dispatching problem is allocating jobs to AGVs to minimizing QC delay and AGV total travel distance. Due to the highly dynamic nature of container terminal environment, the effect of dispatching is hard to predict thus it leads to frequent modification of dispatching results. Given this situation, single rule-based approach is widely used due to its simplicity and small computational cost. However, single rule-based approach has a limitation that cannot guarantee a satisfactory performance for the various performance measures. In this paper, dispatching strategy based on multicriteria heuristics is proposed. Proposed strategy consists of multiple decision criteria. A muti-objective evolutionary algorithm is applied to optimize weights of those criteria. The result of simulation experiment shows that the proposed approach outperforms single rule-based dispatching approaches.

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User Satisfaction Models Based on a Fuzzy Rule-Based Modeling Approach (퍼지 규칙 기반 모델링 기법을 이용한 감성 만족도 모델 개발)

  • Park, Jungchul;Han, Sung H.
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.3
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    • pp.331-343
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    • 2002
  • This paper proposes a fuzzy rule-based model as a means to build usability models between emotional satisfaction and design variables of consumer products. Based on a subtractive clustering algorithm, this model obtains partially overlapping rules from existing data and builds multiple local models each of which has a form of a linear regression equation. The best subset procedure and cross validation technique are used to select appropriate input variables. The proposed technique was applied to the modeling of luxuriousness, balance, and attractiveness of office chairs. For comparison, regression models were built on the same data in two different ways; one using only potentially important variables selected by the design experts, and the other using all the design variables available. The results showed that the fuzzy rule-based model had a great benefit in terms of the number of variables included in the model. They also turned out to be adequate for predicting the usability of a new product. Better yet, the information on the product classes and their satisfaction levels can be obtained by interpreting the rules. The models, when combined with the information from the regression models, are expected to help the designers gain valuable insights in designing a new product.

CCQC modal combination rule using load-dependent Ritz vectors

  • Xiangxiu Li;Huating Chen
    • Structural Engineering and Mechanics
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    • v.87 no.1
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    • pp.57-68
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    • 2023
  • Response spectrum method is still an effective approach for the design of buildings with supplemental dampers. In practice, complex complete quadratic combination (CCQC) rule is always used in the response spectrum method to consider the effect of non-classical damping. The conventional CCQC rule is based on exact complex mode vectors. Sometimes the calculated complex mode vectors may be not excited by the external loading and errors in the structural responses always arise due to the mode truncation. Load-dependent Ritz (LDR) vectors are associated with the external loading and LDR vectors not excited can be automatically excluded. Also, contributions of higher modes are implicitly contained in the LDR vectors in terms of static responses. To improve the calculation efficiency and accuracy, LDR vectors are introduced in the CCQC rule in the present study. Firstly, the generation procedure of LDR vectors suitable for non-classical damping system is presented. Compared to the conventional LDR vectors, the LDR vectors herein are complex-valued and named as complex LDR (CLDR) vectors. Based on the CLDR vectors, the CCQC rule is then rederived and an improved response spectrum method is developed. Finally, the effectiveness of the proposed method in this paper is verified through three typical non-classical damping buildings. Numerical results show that the CLDR vector is superior to the complex mode with the same number in the calculation. Since the generation of CLDR vectors requires less computational cost and storage space, the method proposed in this paper offers an attractive alternative, especially for structures with a large number of degrees of freedom.

On an Equal Mean Quadratic Classification Rule With Unknown Prior Probabilities

  • Kim, Hea-Jung;Inada, Koichi
    • Journal of Korean Society for Quality Management
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    • v.23 no.3
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    • pp.126-139
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    • 1995
  • We describe a formal approach to the construction of optimal classification rule for the two-group normal classification with equal population mean problem. Based on the utility function of Bernardo, we suggest a balanced design for the classification and construct the optimal rule under the balanced design condition. The rule is characterized by a constrained minimization of total risk of misclassification, the constraint of which is constructed by the process of equation between expected utilities of the two group conditional densities. The efficacy of the suggested rule is examined through numerical studies. This indicates that, in case little is known about the relative population sizes, dramatic gains in accuracy of classification result can be achieved.

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Real-time Intrusion-Detection Parallel System for the Prevention of Anomalous Computer Behaviours (비정상적인 컴퓨터 행위 방지를 위한 실시간 침입 탐지 병렬 시스템에 관한 연구)

  • 유은진;전문석
    • Review of KIISC
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    • v.5 no.2
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    • pp.32-48
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    • 1995
  • Our paper describes an Intrusion Detection Parallel System(IDPS) which detects an anomaly activity corresponding to the actions that interaction between near detection events. IDES uses parallel inductive approaches regarding the problem of real-time anomaly behavior detection on rule-based system. This approach uses sequential rule that describes user's behavior and characteristics dependent on time. and that audits user's activities by using rule base as data base to store user's behavior pattern. When user's activity deviates significantly from expected behavior described in rule base. anomaly behaviors are recorded. Observed behavior is flagged as a potential intrusion if it deviates significantly from the expected behavior or if it triggers a rule in the parallel inductive system.

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A Study of Fatigue Life Prediction for Automotive Spot Weldment Using Local Strain Approach (국부변형률근사법을 이용한 차체 점용접부의 피로수명 예측에 관한 연구)

  • Lee, Song-In;Gwon, Il-Hyeon;Lee, Beom-Jun;Yu, Hyo-Seon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.2
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    • pp.220-227
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    • 2001
  • The fatigue crack initiation life is studied on automotive tensile-shear spot weldment made from cold rolled carbon steel(SPC) sheet by using DCPDM and local strain approach. It can be found that the fatigue crack initiation behavior in spot weldment can be definitely detected by DCPDM system. To predict the fatigue life of spot weldment, the local stresses and strains at the potential critical region are estimated by approximate method based on Neubers rule and elastic-plastic FEM analysis. A satisfactory correlation between the predicted life obtained from Local strain approach based on Neubers rule and experimental life can be found in spot weldment within a factor of 2.