Research Article
Learning Path Generation of ITS Using Markov Decision Process
Song-Hwan Kwon*
,
Jong-Nam Rim,
Chung-Song Ko,
Un-Song Ryu,
Yong-Jin Pak,
Hyon-Il Son
Issue:
Volume 14, Issue 1, February 2026
Pages:
1-13
Received:
27 October 2025
Accepted:
17 November 2025
Published:
30 January 2026
Abstract: Probabilistic and stochastic models such as Bayesian and Hidden Markov models can cope well with system uncertainties, but there is a problem of how learning state prediction and learning path generation are performed independently and how to connect them, and the overall effect of the system may be lost even after the connection. Using a Markov Decision Process, a kind of reinforcement learning model, not only can the prediction of the learning state of a student and the generation of a path be implemented simultaneously in a single model, but also the overall error can be reduced. In this paper, we propose to build an intelligent tutoring system into a Markov Decision Process model, an reinforcement learning model, with the aim of reducing learning path generation error and improving system performance by using Markov decision Process model in intelligent tutoring system. In addition, we propose a learning state evaluation method using a Markov Decision Process model to simultaneously proceed the student’s learning state estimation and the system’s action selection. We also propose a method to apply the value-iteration algorithm to action selection computation in a Markov Decision Process model. Comparison with previous models was carried out and its effectiveness was verified.
Abstract: Probabilistic and stochastic models such as Bayesian and Hidden Markov models can cope well with system uncertainties, but there is a problem of how learning state prediction and learning path generation are performed independently and how to connect them, and the overall effect of the system may be lost even after the connection. Using a Markov De...
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Research Article
Preparation of Briquette by Brown Coal Gangue-blast Furnace Slag Geopolymer Binder and Its Characteristics
Jin Hyok Ri,
Yong Bom Hong,
Gwang Song Yun,
Tok-Hui Ri*,
Myong Il Kim,
Hyen Chol Sim,
Su Chol Zhang
Issue:
Volume 14, Issue 1, February 2026
Pages:
14-21
Received:
29 December 2025
Accepted:
4 February 2026
Published:
25 February 2026
DOI:
10.11648/j.sr.20261401.12
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Abstract: Effective recycling of industrial waste is a very important issue worldwide. Coal gangue is a solid waste generated during coal production and processing, which accounts for 10-20% of coal production, the largest of industrial wastes discharged so far. Geopolymers are three-dimensional amorphous inorganic polymers in the form of Si-O-Al-O-Al, in which silica and alumina precursors with high reaction activity are formed via depolymerization-condensation processes in a highly alkaline environment. In this paper, a geopolymer binder is prepared by combining an alkaline activator prepared from brown coal gangue and blast furnace slag as raw material and from industrial waste silica fume. Also, the properties of these geopolymer binders are examined using them as a briquette binder. At temperatures above 700°C, roasted brown coal gangue is more active than the initial state. The optimum dosage of alkali activator is 10M NaOH, silica fume/NaOH ratio of 3, specific gravity of 1.42, and the addition of binder of 6%. The main polymerization products of the alkali activated brown coal gangue geopolymer samples are N-A-S-H gel and amorphous aluminosilicate gel, while the main polymerization products of the alkali activated brown coal gangue -blast furnace slag geopolymer samples are N-A-S-H gel, C-(A)-S-H gel and amorphous aluminosilicate gel. Blast furnace slag is added during the preparation of briquette binder by brown coal gangue geopolymer, which increase the mechanical strength of the geopolymer binder and the optimum dosage is 30%.
Abstract: Effective recycling of industrial waste is a very important issue worldwide. Coal gangue is a solid waste generated during coal production and processing, which accounts for 10-20% of coal production, the largest of industrial wastes discharged so far. Geopolymers are three-dimensional amorphous inorganic polymers in the form of Si-O-Al-O-Al, in wh...
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