• The Journal of Korean Association of Computer Education
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• v.8 no.1
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• pp.55-63
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• 2005

Recently, web-based E-learning systems have entered the spotlight by providing new learning environments that break down spatial and temporal limitations. The key to building the web-based E-learning system is in determining how to effectively use the system and to evaluate the degree of learning achieved by the students that use it. In traditional off-line learning systems, we can evaluate students by counting how many questions, designed to evaluate their learning achievement, he or she answers correctly within a predetermined time limit. But this method would make individualized learning, a strong point of E-learning systems, impossible because these systems provide same learning strategy to all students even though they achieve a different level of learning. Therefore, in this paper, I will find any relationships between given test answers using fuzzy implication theory, I call these fuzzy correlations, and then generate evaluation results that are reflected in those relationships. I will compare the differences between this evaluation method and a traditional evaluation method where a student takes a test to evaluate his or her learning achievement after some learning period. Finally, I will discuss how we can use these results in individualized learning.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.425-432
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• 2011

To control non-point source pollution at a watershed scale, rainfall-runoff characteristics from forest watersheds should be investigated since the forest is the dominant land use in Korea. Long-term monitoring would be an ideal method. However, computer models have been utilized due to limitations in cost and labor in performing long-term monitoring at the watersheds. In this study, the Geo-spatial interface to the Water Erosion Prediction Project (GeoWEPP) model was evaluated for its runoff prediction from a coniferous forest dominant watersheds. The $R^2$ and the NSE for calibrated result comparisons were 0.77 and 0.63, validated result comparisons were 0.92, 0.89, respectively. These comparisons indicated that the GeoWEPP model can be used in evaluating rainfall-runoff characteristics. To estimate runoff changes from a coniferous forest watershed with various cover degree scenarios, ten cover degree scenarios (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%) were run using the calibrated GeoWEPP model. It was found that runoff increases with decrease in cover degree. Runoff volume was the highest ($206,218.66m^3$) at 10% cover degree, whereas the lowest ($134,074.58m^3$) at 100% cover degree due to changes in evapotranspiration under various cover degrees at the forest. As shown in this study, GeoWEPP model could be efficiently used to investigate runoff characteristics from the coniferous forest watershed and effects of various cover degree scenarios on runoff generation.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.4
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• pp.65-77
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• 2019

Adolescents reach the game-use states of adaptive and maladaptive by the absorption to computer game. Authors claimed that the two states are commonly related with the time of game-use, and the degree of them are distinctive according to adolescent individuals, specifically their self-control propensity. Authors proposed a conceptual research model that Big Five personality types predict their self-control which moderates the relationships from game use-time to the maladaptive and adaptive states. The data to test its validity and reliability had been sampled 999 Korean students in elementary school, middle school, and high school. Resultingly, the openness and conscientiousness of the adolescents affected positively on the self-control, which moderated negatively the relationship from the game use time to the maladaptive use state, but the positive moderation on the relationships from game use time to adpative state was not significant. These results mean that we could apply teenager's Big Five personality type and their self-control traits as a tool for preventing teens from the overuse state like addiction.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.318-326
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• 2022

Marketing stress testing is a new method of identifying the company's strengths and weaknesses in a turbulent environment. Technically, this is a complex procedure, so it involves artificial intelligence and machine learning. The main problem is currently the development of methodological approaches to the development of the company's digital model, which will provide a framework for machine learning. The aim of the study was to identify and develop an author's approach to the parameterization of the company's business processes for machine learning-based marketing stress testing. This aim provided the company's activities to be considered as a set of elements (business processes, products) and factors that affect them (marketing environment). The article proposes an author's approach to the parameterization of the company's business processes for machine learning-based marketing stress testing. The proposed approach includes four main elements that are subject to parameterization: elements of the company's internal environment, factors of the marketing environment, the company' core competency and factors impacting the company. Matrices for evaluating the results of the work of expert groups to determine the degree of influence of the marketing environment factors were developed. It is proposed to distinguish between mega-level, macro-level, meso-level and micro-level factors depending on the degree of impact on the company. The methodological limitation of the study is that it involves the modelling method as the only one possible at this stage of the study. The implementation limitation is that the proposed approach can only be used if the company plans to use machine learning for marketing stress testing.

• The Journal of Korean Association of Computer Education
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• v.15 no.1
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• pp.55-64
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• 2012

The purpose of this study is to identify how realism of pedagogical agent can have impacts on persona effect and cognitive load factors. Eighty-two college students participated, and the independent variables of this study were the degree of image details and presence of gesture. The degree of image details were picture, illustration, and line-drawing. The $3{\times}2$ factorial design was applied. There was a significant interaction effect on the engaging of agent persona instrument. When the learners were under the condition of line-drawing agent without gesture, they showed the highest score on engaging of the agent persona instrument. Regarding the cognitive load factors, when learners under the condition of line-drawing showed the highest score of self-evaluation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.379-386
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• 2014

As the use of mobile device is increasing rapidly, the number of users is also increasing. However, most of the app stores are using recommendation of simple ranking method, so the accuracy of recommendation is lower. To recommend an item that is more appropriate to the user, this paper proposes a technique that reflects the weight of user information and recent preference degree of item. The proposed technique classifies the data set by categories and then derives a predicted value by applying the user's information weight to the collaborative filtering technique. To reflect the recent preference degree of item by categories, the average of items' rating values in the designated period is computed. An item is recommended by combining the two result values. The experiment result indicated that the proposed method has been more enhanced the accuracy, appropriacy, compared to item-based, user-based method.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.1
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• pp.60-70
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• 1995

In the field of marine transportation the energy saving is one of the most important factors for profit. In order to reduce the fuel oil consumption the ship's propulsion efficiency must be increased as much as possible. The propulsion efficiency depends upon a combination of an engine and a propeller. The propeller has better efficiency as lower rotational speed. This situation led the engine manufacturers to design the engine that has lower speed, longer stroke and a small number of cylinders. Consequently the variation of rotational torque became larger than before because of the longer delay-time in the fuel oil injection process and an increased output per cylinder. As this new trends the conventional mechanical-hydrualic governors for engine speed control have been replaced by digital speed controllers which adopted the PID control or the optimal control algorithm. But these control algorithms have not enough robustness to suppress the variation of the delay-time and the parameter pertubation. In this paper we consider the delay-time and the perturbation of engine parameters as the modeling uncetainties. Next we design the controller which has zero offset in steady state engine speed, based on the two-degree-of-freedom control theory and $\mu$-synthesis. Thd validity of the controller is investigated through the response simulation. We use a personal computer and an analog computer as the digital controller and the engine (plant) part respectively. And, we certify that the designed controller maintains its performance even though the engine parameters may vary.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.301-310
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• 2002

Internet has been applied to the educational field such as data search, lecture by motion picture, realtime examination. Most questions made for these remote examinations use methods of making questions randomly using fixed questions or item pools. The designed system in this paper makes questions without knowing MARK-UP language and after undergoing examinations on Web. Also it readjusts degree of difficulty automatically on the basis of the rate of correct answers. In addition, this enables learners to perform feedback learning after examinations and subsequently learners themselves to adjust their degree of difficulty and undergo reexaminations. The automatic selection system makes it easy to select questions, possible to expect average marks and number of questions made, and to prevent that questions may be made too easy or too hard. For a remote examination, as there are much possibilities of dishonesty such as examination by proxy so different types of problems are made, and problems of the rationality caused from that can be avoided.

• Journal of Korean Public Health Nursing
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• v.17 no.2
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• pp.203-211
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• 2003

The purpose of this study was to investigate the degree of satisfaction in using rehabilitation exercise rooms in public health centers. A total of 100 subjects were participated in the study who were clients of rehabilitation exercise rooms in two public health centers in one city of Kyunggi Do, Korea. Data were collected from March 1 to 30, 2003 using questionnaire. The data were analyzed using SPSS/PC computer program. The result are as follows : 1. The mean age of subjects was 62.6 years old, and men constituted $67.0\%$ of the participants. Most participants $(64\%)$ were in the middle socioeconomic status, and $(65\%)$ of subjects was diagnosed as stroke. 2. Regarding the source of information about rehabilitation exercise room in public health center, $56.0\%$ obtain information from colleagues or neighbors, and for most participants the time required to travel to rehabilitation exercise room was less than 30min on foot. Among rehabilitation services, Taping therapy $(53.0\%)$ was most frequently used among participants, 3. Sum of all satisfaction score was $71.10(\pm6.60,\;range:\;1-90)$ showed higher level of satisfaction. Cost, reliability, and kindness were main factors that affect the degree of satisfaction among participants. 4. Twenty-four percent of the respondents utilized clinic services in the health centers, and $27.4\%$ stoped rehabilitation services from hospitals and/or clinics due to high cost. 5. In the use of rehabilitation exercise room was positively correlated to age (r=.214, p<0.05) and disease duration(r=.241. p<0.05).

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.219-226
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• 2010

Recently most parking control systems provide customers with various services, but most of the services are just the extension of parking spaces, automatic parking control system and so on. It is essential to use the satisfaction degree as the extent that customer are satisfied with parking control system to improve the quality of the system services and diversify the system services. The degree of satisfaction is different from customer to customer in same condition and can be represented as linguistic variables. In this paper, we present therefore a technique that quantify how much customer are satisfied with parking control system and fuzzy inference system architecture as a solution that can help us to make a efficient decision for these parking problems. In this architecture, inference engine using fuzzy logic compares context data with the rules in the fuzzy rule-based system, gets the sub-results, aggregates them and defuzzifies the aggregated result using MATLAB application programming to obtain crisp value. Fuzzy inference system architecture presented in this paper, can be used as a efficient method to analyze the satisfaction degree which is represented as fuzzy linguistic variables by human emotion. And it can be used to improve the satisfaction degree of not only parking system but also other service systems of various domains.