• Title/Summary/Keyword: Problem solving approach

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Eye Movements in Understanding Combinatorial Problems (순열 조합 이해 과제에서의 안구 운동 추적 연구)

  • Choi, In Yong;Cho, Han Hyuk
    • Journal of Educational Research in Mathematics
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    • v.26 no.4
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    • pp.635-662
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    • 2016
  • Combinatorics, the basis of probabilistic thinking, is an important area of mathematics and closely linked with other subjects such as informatics and STEAM areas. But combinatorics is one of the most difficult units in school mathematics for leaning and teaching. This study, using the designed combinatorial models and executable expression, aims to analyzes the eye movement of graduate students when they translate the written combinatorial problems to the corresponding executable expression, and examines not only the understanding process of the written combinatorial sentences but also the degree of difficulties depending on the combinatorial semantic structures. The result of the study shows that there are two types of solving process the participants take when they solve the problems : one is to choose the right executable expression by comparing the sentence and the executable expression frequently. The other approach is to find the corresponding executable expression after they derive the suitable mental model by translating the combinatorial sentence. We found the cognitive processing patterns of the participants how they pay attention to words and numbers related to the essential informations hidden in the sentence. Also we found that the student's eyes rest upon the essential combinatorial sentences and executable expressions longer and they perform the complicated cognitive handling process such as comparing the written sentence with executable expressions when they try the problems whose meaning structure is rarely used in the school mathematics. The data of eye movement provide meaningful information for analyzing the cognitive process related to the solving process of the participants.

A Relief Method to Obtain the Solution of Optimal Problems (최적화문제를 해결하기 위한 완화(Relief)법)

  • Song, Jeong-Young;Lee, Kyu-Beom;Jang, Jigeul
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.1
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    • pp.155-161
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    • 2020
  • In general, optimization problems are difficult to solve simply. The reason is that the given problem is solved as soon as it is simple, but the more complex it is, the very large number of cases. This study is about the optimization of AI neural network. What we are dealing with here is the relief method for constructing AI network. The main topics deal with non-deterministic issues such as the stability and unstability of the overall network state, cost down and energy down. For this one, we discuss associative memory models, that is, a method in which local minimum memory information does not select fake information. The simulated annealing, this is a method of estimating the direction with the lowest possible value and combining it with the previous one to modify it to a lower value. And nonlinear planning problems, it is a method of checking and correcting the input / output by applying the appropriate gradient descent method to minimize the very large number of objective functions. This research suggests a useful approach to relief method as a theoretical approach to solving optimization problems. Therefore, this research will be a good proposal to apply efficiently when constructing a new AI neural network.

Prediction of Shear Strength Using Artificial Neural Networks for Reinforced Concrete Members without Shear Reinforcement (인공신경망을 이용한 전단보강근이 없는 철근콘크리트 보의 전단강도에 대한 예측)

  • Jung, Sung-Moon;Han, Sang-Eul;Kim, Kang-Su
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.18 no.2
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    • pp.201-211
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    • 2005
  • Due to the complex mechanism and various parameters that affect shear behavior of reinforced concrete (RC) members, models on shear tend to be complex and difficult to utilize for design of structural members, and empirical relationships formulated with limited test data often work lot members having a specific range of influencing parameters on shear. As an alternative approach tot solving this problem, artificial neural networks have been suggested by some researchers. In this paper, artificial neural networks were used to predict shear strengths of RC beams without shear reinforcement. Especially, a large database that consists of shear test results of 398 RC members without shear reinforcement was used for artificial neural network analysis. Three well known approaches for shear strength of RC members, ACI 318-02 shear provision, Zsutiy's equation, and Okamura's relationship, are also evaluated with test results in the shear database and compared with neural network approach. While ACI 318-02 provided inaccurate predictions for RC members without shear reinforcement, the empirical equations by Zsutty and Okamura provided more improved prediction of Shear strength than ACI 318-02. The artificial neural networks, however provided the best prediction of shear strengths of RC beams without shear reinforcement that was closest to test results.

A Study on Arbitration Qualification of Intellectual Property Right Dispute - Focus on Korea and China - (지적재산권분쟁의 중재적격에 관한 연구 -한국과 중국을 중심으로-)

  • Choi, Song-Za
    • Journal of Arbitration Studies
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    • v.21 no.2
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    • pp.27-46
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    • 2011
  • In the intellectual based society of the 21th century, intellectual property of nation and enterprise management has been the key element of nation's competitiveness and development. Therefore in countries like Korea, China, and many other countries, intellectual property of advancement strategy are being constructed and intellectual properties are protected at national level. Top priority task of protecting the intellectual property is to efficiently resolute intellectual property right disputes. Considering the nature of intellectual property right and arbitrage system, arbitration to solve intellectual property disputes is realistically the best method. However, not all cases of them are qualified. In order to relieve the intellectual property disputes through arbitration, qualification must be obtained. During the process, generally and globally, intellectual property right dispute is evaluated by three parts, intellectual property right contract dispute, intellectual property right violation dispute, and intellectual property right validity dispute. Based on UN's "Convention on the Recognition and Enforcement of Foreign Arbitral Awards Agreement" in 1958, June 10th, in New York, both arbitrage organization and judgment can be approved in both Korea and China countries. However, as of today, there is a big gap of arbitration qualification between two countries, which can be troublesome if intellectual property right disputes arise. For instance, in Korea, intellectual property right contract disputes and intellectual property right violation disputes are both generally accepted as arbitration qualification. However for intellectual property right validity dispute, arbitration qualification is only accepted for non-registered intellectual property as in copyright entity. It does not apply to other registered intellectual property right as in patents. In China, arbitration qualification is accepted for intellectual property right contract dispute, and also accepted for intellectual property right violation dispute to copyrights but restricted to others. As for intellectual property right validity dispute, arbitration qualification is completely denied. Therefore, when there is an intellectual property right dispute between Korea and China, the biggest problem is whether China will accept arbitrage judgments made in Korea. Theoretically, arbitrage judgement made in Korea should be also accepted in China's court. However, considering the criticism of China's passive nature of arbitration qualification for its own local intellectual property right disputes, it's very unlikely they'll actively accept arbitrary judgment made in foreign countries. Korea and China must have a more open minded approach for intellectual property disputes and arbitration qualification. Base on WTO's Intellectual Property Right Agreement, it's being defined as private right. Therefore, sovereign principle should be the basic principle of solving intellectual property right disputes. Currently, arbitration qualification is expanding internationally. So both Korea and China must also follow the trend expand the arbitration qualification with a more open minded and forward looking approach, for the good of intellectual property disputes.

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Impact of Direct Structured Instruction for Students with Learning Disabilities on Engineering Physics Concepts (공대 물리학 교육에서 학습장애자에 대한 직접교수법의 효과)

  • Hwang, Un-Hak
    • Journal of Practical Engineering Education
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    • v.14 no.1
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    • pp.19-25
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    • 2022
  • This study examined the impact of direct structured approach of students who demonstrate little or no sense of basic engineer concepts in physics courses. This direct structured instruction is one of the methodologies that focuses on explicit and systematic practices in which an instructor set clear learning outcomes and clarifies the direction of the instruction. 90 participants were randomly selected and tested on the areas of problem-solving skills, reasoning, working memory, and processing speed. 20% of the participants were found to be students with basic engineering disabilities. On the other hand, in the direct structured group, 51.7% and 58.0% of the sample group (90 students) showed a 6.3% increase from the mid-term to final examinations, respectively. The subgroups with 50% or lower grades were decreased from 26.7% to 24.5%. However, five students with the lowest grade of 20% were selected as students with learning disabilities in the study and the average scores of mid-term and final exams were increased by 8.6%, which was 17.9% and 26.5%, respectively at the end of the study. As a result, it showed that direct structured approach for students with learning disabilities in the engineer concepts was effective.

Optimal Time Structure for Tag Cognizance Scheme based on Framed and Slotted ALOHA in RFID Networks (RFID 망에서 프레임화 및 슬롯화된 ALOHA에 기반한 Tag 인식 방식을 위한 최적 시간 구조)

  • Choi, Cheon-Won
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.9
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    • pp.29-36
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    • 2010
  • Consider an RFID network configured as a star such that a single reader is surrounded by a crowd of tags. In the RFID network, prior to attaining the information stored at a tag, the reader must cognize the tags while arbitrating a collision among tags' responses. For this purpose, we present a tag cognizance scheme based on framed and slotted ALOHA, which statically provides a number of slots in each frame for the tags to respond. For the evaluation of the cognizance performance, we choose the cognizance completion probability and the expected cognizance completion time as key performance measures. Then, we present a method to numerically calculate the performance measures. Especially, for small numbers of tags, we derive them in a closed form. Next, we formulate a problem to find an optimal time structure which either maximizes the cognizance completion probability under a constraint on the cognizance time or minimizes the expected cognizance completion time. By solving the problem, we finally obtain an optimal number of slots per frame for the tags to respond. From numerical results, we confirm that there exist a finite optimal number of slots for the tags to respond. Also, we observe that the optimal number of slots maximizing the cognizance completion probability tends to approach to the optimal number of slots minimizing the expected cognizance completion time as the constraint on the cognizance time becomes loose.

The Use of Traditional Algorithmic Versus Instruction with Multiple Representations: Impact on Pre-Algebra Students' Achievement with Fractions, Decimals, and Percent (전통적 알고리즘 교수법과 다양한 표상을 활용한 교수법의 비교: 분수, 소수, 퍼센트 내용을 중심으로)

  • Han, Sunyoung;Flores, Raymond;Inan, Fethi A.;Koontz, Esther
    • School Mathematics
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    • v.18 no.2
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    • pp.257-275
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    • 2016
  • The purpose of this study was to investigate the impact of multiple representations on students' understanding of fractions, decimals, and percent. The instructional approach integrating multiple representations was compared to traditional algorithmic instruction, a form of direct instruction. To examine and compare the impact of multiple representations instruction with traditional algorithmic instruction, pre and post tests consisting of five similar items were administered with 87 middle school students. Students' scores in these two tests and their problem solving processes were analyzed quantitatively and qualitatively. The quantitative results indicated that students taught by traditional algorithmic instruction showed higher scores on the post-test than students in the multiple representations group. Furthermore, findings suggest that instruction using multiple representations does not guarantee a positive impact on students' understanding of mathematical concepts. Qualitative results suggest that the limited use of multiple representations during a class may have hindered students from applying their use in novel problem situations. Therefore, when using multiple representations, teachers should employ more diverse examples and practice with multiple representations to help students to use them without error.

Framing Instead of Solving: Approaching the Wicked problem of Restaurant Food Waste through Service Design Research (해결대신 프레이밍: 서비스 디자인 연구를 통해음식점 음식물쓰레기라는 난제에 접근)

  • Punyotai Thamjamrassri;Kun-Pyo Lee;Yong-Ki Lee
    • Journal of Service Research and Studies
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    • v.12 no.3
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    • pp.93-114
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    • 2022
  • The hospitality and food service sector is the food sector that generates the most food waste. To deliver a more sustainable service, the food service industry needs to understand and reduce customer plate waste, which is mostly avoidable. Several studies have investigated the drivers of plate waste behaviors and proposed mitigations. However, service designers need actionable insights that inspire innovative solutions. The goals of this study are twofold. The first goal is to identify factors influencing young consumers' food waste behavior in restaurants. The second goal is to frame food waste challenges as design opportunities for service designers. A photo diary was conducted with 10 Korean university students. Participants took before and after photos of two meals and fill out questionnaires. The questions include personal background, considerations when choosing a meal, satisfaction with the meal, and reasons for leaving food. Both qualitative and quantitative data were collected and analyzed. The results suggest that lack of awareness and control are the key drivers of leftovers. The food waste problem is framed into "How Might We" design opportunities for service design. Interventions should focus on improving communication with oneself, dining partners, and restaurants. The paper contributes by demonstrating the service design research approach to framing wicked problems with the example of restaurant food waste.

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.

A Study on Forecasting Accuracy Improvement of Case Based Reasoning Approach Using Fuzzy Relation (퍼지 관계를 활용한 사례기반추론 예측 정확성 향상에 관한 연구)

  • Lee, In-Ho;Shin, Kyung-Shik
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.67-84
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    • 2010
  • In terms of business, forecasting is a work of what is expected to happen in the future to make managerial decisions and plans. Therefore, the accurate forecasting is very important for major managerial decision making and is the basis for making various strategies of business. But it is very difficult to make an unbiased and consistent estimate because of uncertainty and complexity in the future business environment. That is why we should use scientific forecasting model to support business decision making, and make an effort to minimize the model's forecasting error which is difference between observation and estimator. Nevertheless, minimizing the error is not an easy task. Case-based reasoning is a problem solving method that utilizes the past similar case to solve the current problem. To build the successful case-based reasoning models, retrieving the case not only the most similar case but also the most relevant case is very important. To retrieve the similar and relevant case from past cases, the measurement of similarities between cases is an important key factor. Especially, if the cases contain symbolic data, it is more difficult to measure the distances. The purpose of this study is to improve the forecasting accuracy of case-based reasoning approach using fuzzy relation and composition. Especially, two methods are adopted to measure the similarity between cases containing symbolic data. One is to deduct the similarity matrix following binary logic(the judgment of sameness between two symbolic data), the other is to deduct the similarity matrix following fuzzy relation and composition. This study is conducted in the following order; data gathering and preprocessing, model building and analysis, validation analysis, conclusion. First, in the progress of data gathering and preprocessing we collect data set including categorical dependent variables. Also, the data set gathered is cross-section data and independent variables of the data set include several qualitative variables expressed symbolic data. The research data consists of many financial ratios and the corresponding bond ratings of Korean companies. The ratings we employ in this study cover all bonds rated by one of the bond rating agencies in Korea. Our total sample includes 1,816 companies whose commercial papers have been rated in the period 1997~2000. Credit grades are defined as outputs and classified into 5 rating categories(A1, A2, A3, B, C) according to credit levels. Second, in the progress of model building and analysis we deduct the similarity matrix following binary logic and fuzzy composition to measure the similarity between cases containing symbolic data. In this process, the used types of fuzzy composition are max-min, max-product, max-average. And then, the analysis is carried out by case-based reasoning approach with the deducted similarity matrix. Third, in the progress of validation analysis we verify the validation of model through McNemar test based on hit ratio. Finally, we draw a conclusion from the study. As a result, the similarity measuring method using fuzzy relation and composition shows good forecasting performance compared to the similarity measuring method using binary logic for similarity measurement between two symbolic data. But the results of the analysis are not statistically significant in forecasting performance among the types of fuzzy composition. The contributions of this study are as follows. We propose another methodology that fuzzy relation and fuzzy composition could be applied for the similarity measurement between two symbolic data. That is the most important factor to build case-based reasoning model.