• Journal of KIISE:Software and Applications
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• v.36 no.6
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• pp.479-490
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• 2009

A number of temporal abstraction approaches have been suggested so far to handle the high computational complexity of Markov decision problems (MDPs). Although the structure of temporal abstraction can significantly affect the efficiency of solving the MDP, to our knowledge none of current temporal abstraction approaches explicitly consider the relationship between topology and efficiency. In this paper, we first show that a topological measurement from complex network literature, mean geodesic distance, can reflect the efficiency of solving MDP. Based on this, we build an incremental method to systematically build temporal abstractions using a network model that guarantees a small mean geodesic distance. We test our algorithm on a realistic 3D game environment, and experimental results show that our model has subpolynomial growth of mean geodesic distance according to problem size, which enables efficient solving of resulting MDP.

• Journal of KIISE:Software and Applications
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• v.30 no.5_6
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• pp.540-549
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• 2003

In collaborative recommendation two models are generally used: the user model and the article model. A user model learns correlation between users preferences and recommends an article based on other users preferences for the article. Similarly, an article model learns correlation between preferences for articles and recommends an article based on the target user's preference for other articles. In this paper, we investigates various combination methods of the user model and the article model for better recommendation performance. They include simple sequential and parallel methods, perceptron, multi-layer perceptron, fuzzy rules, and BKS. We adopt the multi-layer perceptron for training each of the user and article models. The multi-layer perceptron has several advantages over other methods such as the nearest neighbor method and the association rule method. It can learn weights between correlated items and it can handle easily both of symbolic and numeric data. The combined models outperform any of the basic models and our experiments show that the multi-layer perceptron is the most efficient combination method among them.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.97-102
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• 2005

Anaerobic decomposition is one of the most common processes in nature and has been extensively used in waste and wastewater treatment for several centuries. New applications and system modifications continue to be adapted making the process either more effective, less expensive, or suited to the particular waste in question and the operation to which it is to be applied. Animal manure is a highly biodegradable organic material and will naturally undergo anaerobic fermentation, resulting in release of noxious odors, such as in manure storage pits. Depending on the presence or absence of oxygen in the manure, biological treatment process may be either aerobic or anaerobic. Under anaerobic conditions, bacteria carry on fermentative metabolisms to break down the complex organic substances into simpler organic acids and then convert them to ultimately formed methane and carbon dioxide. Anaerobic biological systems for animal manure treatment include anaerobic lagoons and anaerobic digesters. Methane and carbon dioxide are the principal end products of controlled anaerobic digestion. These two gases are collectively called biogas. The biogas contains $60\~70\%$ methane and can be used directly as a fuel for heating or electrical power generation. Trace amounts of ammonia and hydrogen sulfide ($100\~300\;ppm$) are always present in the biogas stream. Anaerobic lagoons have found widespread application in the treatment of animal manure because of their low initial costs, ease of operation and convenience of loading by gravity flow from the animal buildings. The main disadvantage is the release of odors from the open surfaces of the lagoons, especially during the spring warm-up or if the lagoons are overloaded. However, if the lagoons are covered and gases are collected, the odor problems can be solved and the methane collected can be used as a fuel. Anaerobic digesters are air-tight, enclosed vessels and are used to digest manure in a well-controlled environment, thus resulting in higher digestion rates and smaller space requirements than anaerobic lagoons. Anaerobic digesters are usually heated and mixed to maximize treatment efficiency and biogas production. The objective of this work was to review a current anaerobic biological treatment of animal manure for effective new technologies in the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.342-347
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• 2002

After the industrial revolution in 20 century, the world are preparing for new revolution that is society with knowledge for a basis such as IT(Information Technology), NT(Nano Technology) and BT(Bio Technology). Recently, NT is applied to various fields that are composed of science, industry, media and semiconductor-micro technology. It has need of IT that is ultra-precision positioning technology with strokes of many hundreds mm and maintenance of nm precision in fields of ultra micro process, ultra precision measurement, photo communication part and photo magnetic memory. Performance test of servo control system that is used ultra-precision positioning system with single plane X-Y stage is performed by simulation with Matlab. Analyzed for previous control algorithm and adapted for modern control theory, dual servo algorithm is developed by minimum order observer, and stability and priority on controller are secured. Through the simulation and experiments on ultra precision positioning, stability and priority on ultra-precision positioning system with single plane X-Y stage and control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE

• Journal of the Korean Society of School Health
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• v.32 no.3
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• pp.144-151
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• 2019

Purpose: The purpose of this study is to examine academic stress, social support and learning management system(LMS) utilization satisfaction of learners attending online graduate schools and understand the factors influencing their academic persistence. Methods: The participants were students of K online graduate school and the data of 143 students, in total, were collected from April to May in 2019. For data analysis, frequency analysis, x² test, t-test, F-test, Pearson's correlation and multiple regression analysis were conducted using SPSS ver. 23. Results: Academic stress, social support, and LMS utilization satisfaction were associated with academic persistence of online graduate students. The multiple regression analysis of the factors influencing academic persistence showed that the model was significant (p<.001) with an explanatory power of 23% and that significant factors influencing it were academic stress (β=-.23, p=.002), LMS utilization satisfaction (β=.31, p<.001) and jobs (β=.23, p=.002). Conclusion: Although the online graduate students' level of academic persistence was high, it is required to develop strategies to alleviate their academic stress and increase LMS utilization rate in order to increase their persistence to academic success. In addition, it is necessary to provide the foundation on which the utilization of major knowledge regarding jobs can be enhanced, reflecting the characteristics of online graduate students. Furthermore, this study is expected to contribute to the extension of professional and advanced education in response to social needs by developing a variety of online high education learning systems beyond time and space.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.229-232
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• 2005

In this paper, an image-based "approach-align -grasp" visual servo control design is proposed for the problem of object grasping, which is based on the binocular stand-alone system. The basic idea consists of considering a vision system as a specific sensor dedicated a task and included in a control servo loop, and we perform automatic grasping follows the classical approach of splitting the task into preparation and execution stages. During the execution stage, once the image-based control modeling is established, the control task can be performed automatically. The proposed visual servoing control scheme ensures the convergence of the image-features to desired trajectories by using the Jacobian matrix, which is proved by the Lyapunov stability theory. And we also stress the importance of projective invariant object/gripper alignment. The alignment between two solids in 3-D projective space can be represented with view-invariant, more precisely; it can be easily mapped into an image set-point without any knowledge about the camera parameters. The main feature of this method is that the accuracy associated with the task to be performed is not affected by discrepancies between the Euclidean setups at preparation and at task execution stages. Then according to the projective alignment, the set point can be computed. The robot gripper will move to the desired position with the image-based control law. In this paper we adopt a constant Jacobian online. Such method describe herein integrate vision system, robotics and automatic control to achieve its goal, it overcomes disadvantages of discrepancies between the different Euclidean setups and proposes control law in binocular-stand vision case. The experimental simulation shows that such image-based approach is effective in performing the precise alignment between the robot end-effector and the object.

• Proceedings of the KAIS Fall Conference
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• 2002.11a
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• pp.300-302
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• 2002

This study develops a model fer establishing and operating "Arts and Humanities Business Incubators (AHBI)" to improve the productivity in the field of arts and humanities, the major resource of the knowledge-based society. The AHBI is a center that provides general assistance to those who want to start a new business in the area of arts and humanities and continue to provide managerial consultation to those who graduated from the AHBI. This research provides systematically how to provide the hardwares such as of office space and furniture, and how to supply the softwares such as management skills, financing, and marketing. This research indicates that the Ministry of Small and Medium-sized Industry should develop AHBIs, and suggests that the Ministry of Culture and Tourism establish AHBIs in its Cultural Industry Incubation Centers. This research expects that a government research institute or professional institute operates AHBI to create job opportunities for arts and humanities majors, to add the academic value of arts and humanities, and to vitalize the local economy.

• Journal of KIISE
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• v.42 no.3
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• pp.341-360
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• 2015

While architectural patterns provide software development solutions by providing schemas for structural organizations of software systems based on empirical knowledge, Jackson's problem frames provide a method of analyzing software problems. Problem frames are useful to understanding the software development problem, by putting emphasis on the problem domain, rather than on the solution space. Research exists that relates problem frames and software architecture, but most of this research uses problem frames only to understand given problems. Moreover, none of the existing research derives architectural patterns by considering both problem frames and quality attributes. In this paper, we propose a software architecture design method for pattern-based architecture design, by matching problem frames and architectural patterns. To that end, our approach first develops the problem model based on the problem frames approach, and then uses it to match with candidate architectural patterns, from the perspectives of both functionality, and quality attributes. Functional matching uses the problem frame diagram to match the problem model of an architectural pattern. We conduct a case study to show that our approach can systematically decide the right architectural patterns, and provide a basis for fine-grained software architecture design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.7
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• pp.2205-2212
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• 1996

In order to move the body of a walking robot translationally, and step over the obstacles, the walking robot must have at least 3 degrees of freedom for each leg. Therefore each leg of the general walking robots can be composed of 3-link system with 3 revolute joints. In this paper, the colsed form of inverse kinimatic solutions is shown for this general 3R linkage. Moreover, in order to have efficient walking volume in rough terrain, the workspace of each log is obtained considering the twist angles and the offsets in D-H parameters. When we design a walking robot, the information of the walking volume is needed for planning desired trajectories of the feet effectively. Appropriate knowledge of the walking volume can also be used to maximize linear or angular velocity of minimize power of stress. However, since it is impossible to obrain the information of walking volume in 3-D space directly from the kinematic equations, the walking volume can be searched through the edge detection algorithm using the triangle tracer with closed from inverse kinematic solutions. In this study, we present the closed form inverse kinematic solutions for 3R linkage model, and the walking volume of 6 legged walking robot which is modeled after the darking bettle, Eleodes obscura sulcipennis, through the method of edge detection for an arbitrary 2 dimensional shape using triangle tracer.

• Korean Journal of Community Nutrition
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• v.2 no.3
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• pp.388-395
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• 1997

A survey was conducted to investigate housewives' perception and consumption of Korean fermented foods marketed in Taejon. Most subjects know how to prepare Kimchi(seasoned and fermented vegetables), 65-67% can make Kochujang(fermented red pepper soybean paste), Toenjang(Korean style soysauce) and Jang-atchies(pickled basic side dishes), 56% can make Kuk-ganjang(Korean style coysauce), 45% can make Chonggukjang (fermented soybean) and 34% can make Jot-kals(salt-fermented fish products). With decreasing age(p<0.0001), not many other subjects could make other fermented foods besides Kimchi. The percentages of subjects buying fermented foods were 71.5% for Chin-ganjang(Japanese style soysauce), 51.7% Jot-kals, 27.1%Kochujang, 25.7% Chonggukjang, 20.1% Jang-atchies, 10.4% Toenjang, 5.9% Kuk-ganjang, and 3.8% Kimchi. the uounger in age, the higher the tendency to buy marketed Kimchies(p<0.05) and Kochujang(p<0.01). The resons for purchasing fermented foods were convenience (52.9%), lack of preparation knowledge(17.5%), lack of time for preparation(12.5%), and lack of space for food storage(8.2%). Subjects indicated that their reasons for mot buying were as follows : use of additives or unreliability with regard to manufacturing dates(45%), bad taste(21%), unsanitary treatment(16%) and to keep their indigenous taste(14%). They cosidered expiration dates, taste, crpteria and safety as the important standard in selecting marketed foods. Younger subjects insisted on the improvement of sanitary condition and partial change of taste to increase the consumption of fermented foods. However, older subjects thought it best to keep the taste original for more utilization of fermented foods.