• Title/Summary/Keyword: statistical problem solving process

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A Study on Success Factors of Buyer - Supplier Relationship in Elementary School Lunch : From the buyer's viewpoint (초등학교 급식에서 구매자 - 공급자 관계의 성공요인에 관한 연구 - 구매자의 관점에서 -)

  • Lee, Yun-Ju;Park, Gyeong-Suk
    • Journal of the Korean Dietetic Association
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    • v.8 no.1
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    • pp.1-8
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    • 2002
  • The purpose of this study is to clarify success factors for desirable relationship between buyer and supplier in elementary school. Therefore, the survey questionnaire consisted of general background, past success, success difference, buyer-supplier relationship characteristics(trust, supporting status, communication behavior, conflict resolution techniques, supplier selection process). The subjects were 66 dieticians of elementary school in Inchon. The statistical analysis of data was completed using SPSS program. The results were summarized as follows : Average total cost/day per one person ₩1,156. The number of suppliers per one school were 6. 92.3% of the subjects were in favor of private contract, regarding contract methods of purchasing food materials. For the past success, degree of satisfaction about past their supplier showed 3.49 score. The present success difference was shown higher than the past success. There was significant correlation between the past success and the present success difference. Trust about suppliers showed 3.40score. Supplying companies hardly support for buying school. Among information quality(timely, accurate, adequate, complete, credible), timely and complete showed lower score than the other kind of elements. Among the buyer-supplier relationship characteristic elements, only trust correlated with satisfaction about suppliers significantly. Among the conflict resolution techniques, joint problem solving and persuasive attempts were often made use of by subjects. The supplier selection criteria were shown quality(7.47), supplier's capabilities(6.46), management plan(6.00), price(5.73), scale(5.48), assets(5.27), considers delivery(4.76) and technology(2.39). As results, trust was needed for the desirable relationship between buyers and suppliers. This study has some limitations. The data in this study were collected from only buyer. It is more desired to acquire data from suppliers also.

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An Analysis of Recruitment Importance and Priority of According to the introduction of NCS(National Competency Standards) in Sports Public Institution (NCS(국가직무능력표준) 도입에 따른 스포츠계열 공공기관의 채용 중요도 및 우선순위 분석)

  • Kim, Dong-Man
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.5
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    • pp.1409-1417
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    • 2020
  • The purpose is to increase the likelihood of physical education students for employment in public institutions by examining the priority for hiring sports-related public institutions. The subject of the study was purposeful sampling of a total of 11 persons including 4 sports professors, 3 NCS experts in sports field, 2 judges from public sports institutions, and 2 personnel in charge of hiring public institutions. Through this process, from January 3 to March 12, 2020, the importance of priority was analyzed using hierarchical structure analysis using the main factors of NCS vocational basic competency. All data are coded so that statistical processing can be performed. Using SPSS/PC (ver. 21.0) for Windows, the hierarchical structure analysis was used for frequency analysis and priority determination. First, communication skills (.231), organizational comprehension skills (.177), resource management skills (.128), interpersonal skills (.110), vocational ethics (.082), problems in the major areas of recruitment of sports-related public institutions Solving ability (.061), information ability (.056), mathematical ability (.054), self-development ability (.052), and description ability (.049) were analyzed in order. Second, in terms of evaluation items, communication is communication skills (.442), mathematical skills are basic computation skills (.512), problem solving skills are thinking skills (.722), self-development skills are self-management skills (.587), Resource management ability was analyzed in order of time management ability (.531), interpersonal relationship ability as teamwork ability (.382), information ability in computer use ability (.677), technical ability in technology understanding ability (.599).

An Evaluation on the Effectiveness of Public Health Education by the SNU Graduates Currently Working at Health-related Jobs (보건분야 종사 졸업생에 의한 서울대학교 보건대학원 교육효과 평가)

  • 이상이;문옥륜
    • Korean Journal of Health Education and Promotion
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    • v.14 no.2
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    • pp.43-57
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    • 1997
  • Educational goals of SPH were two-fold : One was to train a health professions who should take charge of a leading roles, another were to educate the researchers of public health. There were strong demands to evaluate whether these goals had been effectively achieved through the master's course of SPH or not. According to the educational goals of SPH, public health is an applied science to be applicable to health-related fields. The curriculum of SPH has to be built under this principle and be evaluated by someone regularly. Who evaluates that? The most pertinent appraiser is the graduates of public health currently working at health-related jobs. It was the purpose of the study to let the graduates evaluate their education and the curriculum that they had undertaken during master's course at SNU. If the results of the evaluation by the graduates were not satisfactory, we should find the actual causes of low scored apraisal and reform the curriculum of SPH as the process of problem solving. During September and October 1996, a postal survey was undertaken of the 293 SNU graduates of public health who had been engaged in the health related jobs. As 198 graduates answered out of 293, the response rate was 67.6%. The questionnaire was designed to ascertain how well the SNU master's course of public health had helped their practice. The SAS package was used for statistical analysis and $x^2$-test as a test of statistical significance. Major findings of the study were summarized as follows: $\cdot$ The health related abilities consisted of three categories, which were health administration abilities composed of 14 items, health education abilities composed of 5 items, health research abilities composed of 10 items. $\cdot$ The respondents had acquired 'Worldwide trends of health policy', 'evaluation concepts of health projects', 'interpersonal relationships in professional life', and 'communication through writings' moe than other detailed items in the category of health administration abilities. $\cdot$ 'Establishment of educational and learning golas' was the most acquired item of 5 detailed items of health education abilities. $\cdot$ Respondents indicated that they had acquired ability 'to search reference', ' to understand health problems', 'to establish study plannings', and 'to collect health related data' more than other detailed items in the category of health research abilities.

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First-year College Students' Perception toward Their Secondary School Technology Classrooms and Teachers (중등학교 기술 수업과 기술 교사에 대한 대학 신입생의 인식)

  • Kwon, Hyuk-Soo;Mo, Joo-Soon
    • 대한공업교육학회지
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    • v.39 no.2
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    • pp.37-57
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    • 2014
  • This study investigated perception of first-year college students who recently experienced technology education in their secondary education for describing contemporary technology classrooms. To accomplish this goal, survey and in-depth interview on their technology classrooms were employed. Participants in this study were 427 first-year college students who began their college life in 2013 and consisted of 224 students enrolled in 10 departments of educational major and 203 students who enrolled in 9 departments of other colleges. The instrument of this study consisted of preference toward technology classrooms and teachers, experience in the secondary technology classrooms, perception toward technology teachers, and suggestions for technology classrooms with five point Likert scales and open-ended questionnaires. And individual in-depth interviews with 22 volunteers who answered the instrument and consented the interview process were conducted. Based on the collected data, statistical and theme analyses were performed and the key findings were as follows. First-year students' experiences for technology classrooms were described with the theme of 'learning contents or activities'(54.4%). And the negative perception toward technology classrooms(29.1%) was larger than he positive perception(16.5%). The perception toward technology classrooms was also presented with two themes of teaching methods and subject interest. The perception toward technology teachers presented a medium level preference with several themes of teachers' teaching methods, teachers' personality, and subject interest. Lecture style method(60.48%) was largely used in the participants' technology classrooms and problem solving or collaborative methods was not frequent(19.31%). The participants indicated a need for improving teaching methods in technology education and suggested sufficient administration and curriculum supports and transitions of the learning contents. Further studies investigating the diverse public's perception toward technology and technology classrooms could be recommended.

Knowledge Extraction Methodology and Framework from Wikipedia Articles for Construction of Knowledge-Base (지식베이스 구축을 위한 한국어 위키피디아의 학습 기반 지식추출 방법론 및 플랫폼 연구)

  • Kim, JaeHun;Lee, Myungjin
    • Journal of Intelligence and Information Systems
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    • v.25 no.1
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    • pp.43-61
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    • 2019
  • Development of technologies in artificial intelligence has been rapidly increasing with the Fourth Industrial Revolution, and researches related to AI have been actively conducted in a variety of fields such as autonomous vehicles, natural language processing, and robotics. These researches have been focused on solving cognitive problems such as learning and problem solving related to human intelligence from the 1950s. The field of artificial intelligence has achieved more technological advance than ever, due to recent interest in technology and research on various algorithms. The knowledge-based system is a sub-domain of artificial intelligence, and it aims to enable artificial intelligence agents to make decisions by using machine-readable and processible knowledge constructed from complex and informal human knowledge and rules in various fields. A knowledge base is used to optimize information collection, organization, and retrieval, and recently it is used with statistical artificial intelligence such as machine learning. Recently, the purpose of the knowledge base is to express, publish, and share knowledge on the web by describing and connecting web resources such as pages and data. These knowledge bases are used for intelligent processing in various fields of artificial intelligence such as question answering system of the smart speaker. However, building a useful knowledge base is a time-consuming task and still requires a lot of effort of the experts. In recent years, many kinds of research and technologies of knowledge based artificial intelligence use DBpedia that is one of the biggest knowledge base aiming to extract structured content from the various information of Wikipedia. DBpedia contains various information extracted from Wikipedia such as a title, categories, and links, but the most useful knowledge is from infobox of Wikipedia that presents a summary of some unifying aspect created by users. These knowledge are created by the mapping rule between infobox structures and DBpedia ontology schema defined in DBpedia Extraction Framework. In this way, DBpedia can expect high reliability in terms of accuracy of knowledge by using the method of generating knowledge from semi-structured infobox data created by users. However, since only about 50% of all wiki pages contain infobox in Korean Wikipedia, DBpedia has limitations in term of knowledge scalability. This paper proposes a method to extract knowledge from text documents according to the ontology schema using machine learning. In order to demonstrate the appropriateness of this method, we explain a knowledge extraction model according to the DBpedia ontology schema by learning Wikipedia infoboxes. Our knowledge extraction model consists of three steps, document classification as ontology classes, proper sentence classification to extract triples, and value selection and transformation into RDF triple structure. The structure of Wikipedia infobox are defined as infobox templates that provide standardized information across related articles, and DBpedia ontology schema can be mapped these infobox templates. Based on these mapping relations, we classify the input document according to infobox categories which means ontology classes. After determining the classification of the input document, we classify the appropriate sentence according to attributes belonging to the classification. Finally, we extract knowledge from sentences that are classified as appropriate, and we convert knowledge into a form of triples. In order to train models, we generated training data set from Wikipedia dump using a method to add BIO tags to sentences, so we trained about 200 classes and about 2,500 relations for extracting knowledge. Furthermore, we evaluated comparative experiments of CRF and Bi-LSTM-CRF for the knowledge extraction process. Through this proposed process, it is possible to utilize structured knowledge by extracting knowledge according to the ontology schema from text documents. In addition, this methodology can significantly reduce the effort of the experts to construct instances according to the ontology schema.

A Study on the Goal-Orientation of QI Performers in the Medical Centers (의료기관 QI 담당자의 목표추구몰입에 관한 연구)

  • Kim, Mi-Sook;Park, Jae-Sung
    • The Korean Journal of Health Service Management
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    • v.2 no.1
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    • pp.105-124
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    • 2008
  • The purpose of this research is to provide the data base for the activation of Quality Improvement operation through investigating the status of Quality Improvement operation, and finding out factors influencing on the goal-orientation of QI performers in the medical centers of more than one hundred beds where are practicing Quality Improvement operation. In order to reach the purpose, document study was carried out grounded on the proceeding researches and formulated statistical data in relation with the status of Quality Improvement performers, and proof study was carried out through questionnaire survey. The subjects of the survey were the Quality Improvement performers working in seventy three medical centers in Pusan-Gyeongnam, Daegu-Gyeongbuk, and Ulsan. Among eighty three Quality Improvement performers, fifty, five were questionnaire surveyed, on the result of which Reliability Analysis, Factor Analysis, and Multiple Regression Analysis were made, using statistical program. The the results of the proof analysis on this research are as follows. First, in the factors influencing the devoting to goal pursuit of QI performers, organization-goal contribution(0.44) had significant positive effects, while organization conflict(-0.25) had significant negative effects. In other words, the higher the organization-goal contribution was, the higher the devoting to goal pursuit was, while the less the organization conflict was, the higher the devoting to goal pursuit was, which was statistically significant.(p<0.05). Second, in the aspect of goal performance types of QI performers, the process-centered type showed high level of the devoting to goal pursuit, which was statistically significant.(p<0.05). Third, in the aspect of QI performance degree, the higher the devoting to goal pursuit was, the higher the QI performance degree was, which was statistically significant.(p<0.05). In addition, the performers who perceived their workplaces organic structure showed much higher QI performance degree, which statistically significant.(p<0.05). Generalizing the results of this research, it is possible to offer a few suggestions as follows. First, as the competition among the medical centers is more severe recently owing to medical center evaluation system, medical centers are practicing various Quality Improvement operation in all of medical services such as clinical performance and management performance, to reach the purpose of both cost-cutting and medical quality improvement. Thus in order to practice Quality Improvement operation more efficiently in medical centers, it is essential to nuke use of problem-solving methods and statistical members. This as the willingness of chief executives and positive attitude and recognition of organization members. This requires the installation of divisions in charge and disposition of persons in charge, not to speak of persistent training of Quality Improvement. Second, the divisions in charge of QI carry out Quality Improvement operation at the medical center level, and take the role of generalizing and adjusting QI performances of various departments. Owing to this role, the division in charge of QI is considered indispensable organization in the QI operation of medical centers along with medical QI committee, while it contributes to the government's goal of reducing quality level gaps among medical centers. Therefore it is necessary for government and QI organizations to give institutional support and resources for the sake of QI operation of medical centers, besides to supply systematic trainning and informations to the divisions and persons in charge of QI. Third, it is certain that disposition of persons in charge should be determined in view of the scale and the scope of QI operation in medical centers.

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Ensemble Learning with Support Vector Machines for Bond Rating (회사채 신용등급 예측을 위한 SVM 앙상블학습)

  • Kim, Myoung-Jong
    • Journal of Intelligence and Information Systems
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    • v.18 no.2
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    • pp.29-45
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    • 2012
  • Bond rating is regarded as an important event for measuring financial risk of companies and for determining the investment returns of investors. As a result, it has been a popular research topic for researchers to predict companies' credit ratings by applying statistical and machine learning techniques. The statistical techniques, including multiple regression, multiple discriminant analysis (MDA), logistic models (LOGIT), and probit analysis, have been traditionally used in bond rating. However, one major drawback is that it should be based on strict assumptions. Such strict assumptions include linearity, normality, independence among predictor variables and pre-existing functional forms relating the criterion variablesand the predictor variables. Those strict assumptions of traditional statistics have limited their application to the real world. Machine learning techniques also used in bond rating prediction models include decision trees (DT), neural networks (NN), and Support Vector Machine (SVM). Especially, SVM is recognized as a new and promising classification and regression analysis method. SVM learns a separating hyperplane that can maximize the margin between two categories. SVM is simple enough to be analyzed mathematical, and leads to high performance in practical applications. SVM implements the structuralrisk minimization principle and searches to minimize an upper bound of the generalization error. In addition, the solution of SVM may be a global optimum and thus, overfitting is unlikely to occur with SVM. In addition, SVM does not require too many data sample for training since it builds prediction models by only using some representative sample near the boundaries called support vectors. A number of experimental researches have indicated that SVM has been successfully applied in a variety of pattern recognition fields. However, there are three major drawbacks that can be potential causes for degrading SVM's performance. First, SVM is originally proposed for solving binary-class classification problems. Methods for combining SVMs for multi-class classification such as One-Against-One, One-Against-All have been proposed, but they do not improve the performance in multi-class classification problem as much as SVM for binary-class classification. Second, approximation algorithms (e.g. decomposition methods, sequential minimal optimization algorithm) could be used for effective multi-class computation to reduce computation time, but it could deteriorate classification performance. Third, the difficulty in multi-class prediction problems is in data imbalance problem that can occur when the number of instances in one class greatly outnumbers the number of instances in the other class. Such data sets often cause a default classifier to be built due to skewed boundary and thus the reduction in the classification accuracy of such a classifier. SVM ensemble learning is one of machine learning methods to cope with the above drawbacks. Ensemble learning is a method for improving the performance of classification and prediction algorithms. AdaBoost is one of the widely used ensemble learning techniques. It constructs a composite classifier by sequentially training classifiers while increasing weight on the misclassified observations through iterations. The observations that are incorrectly predicted by previous classifiers are chosen more often than examples that are correctly predicted. Thus Boosting attempts to produce new classifiers that are better able to predict examples for which the current ensemble's performance is poor. In this way, it can reinforce the training of the misclassified observations of the minority class. This paper proposes a multiclass Geometric Mean-based Boosting (MGM-Boost) to resolve multiclass prediction problem. Since MGM-Boost introduces the notion of geometric mean into AdaBoost, it can perform learning process considering the geometric mean-based accuracy and errors of multiclass. This study applies MGM-Boost to the real-world bond rating case for Korean companies to examine the feasibility of MGM-Boost. 10-fold cross validations for threetimes with different random seeds are performed in order to ensure that the comparison among three different classifiers does not happen by chance. For each of 10-fold cross validation, the entire data set is first partitioned into tenequal-sized sets, and then each set is in turn used as the test set while the classifier trains on the other nine sets. That is, cross-validated folds have been tested independently of each algorithm. Through these steps, we have obtained the results for classifiers on each of the 30 experiments. In the comparison of arithmetic mean-based prediction accuracy between individual classifiers, MGM-Boost (52.95%) shows higher prediction accuracy than both AdaBoost (51.69%) and SVM (49.47%). MGM-Boost (28.12%) also shows the higher prediction accuracy than AdaBoost (24.65%) and SVM (15.42%)in terms of geometric mean-based prediction accuracy. T-test is used to examine whether the performance of each classifiers for 30 folds is significantly different. The results indicate that performance of MGM-Boost is significantly different from AdaBoost and SVM classifiers at 1% level. These results mean that MGM-Boost can provide robust and stable solutions to multi-classproblems such as bond rating.

The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

Research about feature selection that use heuristic function (휴리스틱 함수를 이용한 feature selection에 관한 연구)

  • Hong, Seok-Mi;Jung, Kyung-Sook;Chung, Tae-Choong
    • The KIPS Transactions:PartB
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    • v.10B no.3
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    • pp.281-286
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    • 2003
  • A large number of features are collected for problem solving in real life, but to utilize ail the features collected would be difficult. It is not so easy to collect of correct data about all features. In case it takes advantage of all collected data to learn, complicated learning model is created and good performance result can't get. Also exist interrelationships or hierarchical relations among the features. We can reduce feature's number analyzing relation among the features using heuristic knowledge or statistical method. Heuristic technique refers to learning through repetitive trial and errors and experience. Experts can approach to relevant problem domain through opinion collection process by experience. These properties can be utilized to reduce the number of feature used in learning. Experts generate a new feature (highly abstract) using raw data. This paper describes machine learning model that reduce the number of features used in learning using heuristic function and use abstracted feature by neural network's input value. We have applied this model to the win/lose prediction in pro-baseball games. The result shows the model mixing two techniques not only reduces the complexity of the neural network model but also significantly improves the classification accuracy than when neural network and heuristic model are used separately.