• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.739-746
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• 2008

The aim of this study is finding the optimal design parameters and the optimal operation variables of a reactive distillation column. Different from steady state optimization, dynamic optimization makes it possible considering operation ability as well as design problems at process design step. For performing dynamic optimization, dynamic simulation should be done first. If dynamic simulation is already finished, dynamic optimization can be performed with less effort than that of dynamic simulation.Reactive distillation systems involving reaction and separation in a single unit have the potential to reduce capital and operating costs, particularly when reaction have conversion constraint or when azeotropes exist making conventional separation difficult and expensive. This study here present work on the continuous distillation process, the homogeneous catalyzed esterification of methanol and acetic acid, the synthesis of methyl acetate. Based on an equilibrium stage model of a reactive distillation column a dynamic optimization problem was formulated and solved. And the results were verified by performing dynamic simulation and showing the variation of conversion and purity as the variation of the operation variables. As the results of dynamic optimization, this study found optimal feed ratio, reflux ratio and reboiler duty of this system. And as this study applied it to dynamic simulations the dynamic characteristics of a reactive distillation column are showed under optimal operating condition.

• Spatial Information Research
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• v.17 no.3
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• pp.397-404
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• 2009

To solve the problems of distribution and quality on land gravity data, airborne gravity survey was performed in 2008 obtaining the airborne gravity data with accuracy of 1.56mGal. Since airborne gravity data is the obtained at the flight height, it is necessary to convert the airborne gravity data to the surface to combine various gravity data and compute precision geoid. In addition, Stokes' integral radius, Stokes' kernel and the radius of terrain effect computation should be optimally determined to calculate precision geoid. In this study, we made an effort to decide the optimal parameters based on the distribution and the characteristic of gravity data. Then, two geoid models were calculated using the selected parameters and the difference of geoid was calculated with mean of -16.95cm and the standard deviation of ${\pm}8.50cm$. We consider that this difference is due to the distribution and errors on the gravity data. For future work, the study on the effect of geoid with newly obtained land gravity data ship-borne gravity data and GPS/Leveling data should be conducted. Furthermore, the study on the downward continuation and terran effect calculation should be studied in detail for better precision geoid construction.

• Journal of the Korea Institute of Building Construction
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• v.17 no.3
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• pp.253-260
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• 2017

As global warming became a worldwide issue, a significant effort has been made on the development of technology related to $CO_2$ capture and storage. Geologic sequestration of $CO_2$ is one of those technologies for safe disposal of $CO_2$. Geologic sequestration stores $CO_2$ in the form of supercritical fluid into the underground site surrounded by solid rock, and concrete is used for prevention of $CO_2$ leakage into the atmosphere. In such case, concrete may experience severe damage by attack of supercritical $CO_2$, and especially in contact with underground water, very aggressive form of carbonation can occur. In this work, to prevent such deterioration in concrete, calcium phosphates were added to the portland cement to produce hydroxyapatite, one of the most stable mineral in the world. Temperature rise, viscosity, set and stiffening, and strength development of cement paste incorporating three different types of calcium phosphates were investigated. According to the results, it was found that the addition of calcium phosphate increased apparent viscosity, but decreased maximum temperature rise and 28 day compressive strength. It was found that monocalcium phosphate was found to be inappropriate for portland cement based material. Applicability of dicalcium and tricalcium phosphates for portland cement needs to be evaluated with further investigation, including the long term compressive strength development.

• Journal of KIISE:Databases
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• v.28 no.3
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• pp.279-300
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• 2001

Data mining plays an important role in knowledge discovery process and usually various existing algorithms are selected for the specific purpose of the mining. Currently, data mining techniques are actively to the statistics, business, electronic commerce, biology, and medical area and currently numerous algorithms are being researched and developed for these applications. However, in a long run, only a few algorithms, which are well-suited to specific applications with excellent performance in large database, will survive. So it is reasonable to focus our effort on those selected algorithms in the future. This paper classifies about 30 existing algorithms into 7 categories - association rule, clustering, neural network, decision tree, genetic algorithm, memory-based reasoning, and bayesian network. First of all, this work analyzes systematic hierarchy and characteristics of algorithms and we present 14 criteria for classifying the algorithms and the results based on this criteria. Finally, we propose the best algorithms among some comparable algorithms with different features and performances. The result of this paper can be used as a guideline for data mining researches as well as field applications of data mining.

• Journal of the Society of Disaster Information
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• v.8 no.2
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• pp.158-170
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• 2012

Citizens'income has been increased along with the trend of rapid changes in society, and the quality of their lives has been improved as well. As much as the degree of increase of quality of life, the number of spectators for performing art events, etc. who desire to fulfill their needs for enjoyment of varied cultural performances have been increasing, and also a large number of spectators enjoys a variety of festivals being held in each provincial area as well as international events: we still remember such frantic rooting shown by citizens during 2002 World Cup drawing attention and interest of entire nation. There are always risks of loss of human lives if accidents occur as there sult of close-packed crowd gathered at the same time. Therefore, it is required to prepare adequate security measures in order to prevent various accidents before hand. It is hoped that this research work would be of help for further efficient and systematic security management for the performing arts centers or public theaters encouraging the event organizer and the private security firm and the Korea Private Security Association to exert great effort and investments in further projects for development of security technology. Also, it is required to build a performance culture to consider audience's safety first from the beginning to the end of the event on the basis of efficient security management. Furthermore, spect at or sare required to recognize the fact that safety in the site for performing arts should be guaranteed for everyone's sake, and, to achieve this, they are obliged to be more cooperative with the event organizer and the private security firm, forming a trinity all together, in order not to have safety threatening situations in the site of performing arts events.

• Journal of Intelligence and Information Systems
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• v.14 no.1
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• pp.117-129
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• 2008

The cost-based scheduling work has been done in both the Operations Research (OR) and Artificial Intelligence (AI) literature. To deal with more realistic problems, AI-based heuristic scheduling approach with non-regular performance measures has been studied. However, there has been little research effort to develop a full inter-job cost propagation algorithm (CPA) for different jobs having multiple downstream and upstream activities. Without such a CPA, decision-making in scheduling heuristics relies upon local, incomplete cost information, resulting in poor schedule performance from the overall cost minimizing objective. For such a purpose, we need two types of CPAs : intra-job CPA and inter-job CPA. Whenever there is a change in cost information of an activity in a job in the process of scheduling, the intra-job CPA updates cost curves of other activities connected through temporal constraints within the same job. The inter-job CPA extends cost propagation into other jobs connected through precedence relationships. By utilizing the cost information provided by CPAs, we propose cost-based scheduling heuristics that attempt to minimize the total schedule cost. This paper develops inter-job CPAs that create and update cost curves of each activity in each search state, and propagate cost information throughout a whole network of temporal constraints. Also we propose various cost-based scheduling heuristics that attempt to minimize the total schedule cost by utilizing the cost propagation algorithm.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.2
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• pp.5-25
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• 2018

This study is a broad examination researchon LIS students' perception about public library's subject special services and subject special librarian. Students majoring in Library and Information Science as respondents, it examined the recognition level of subject special services and subject special librarian, cognition level of necessity, competencies of subject special librarians and students and opinions on special status system of subject psecial librarians. Main factors shown in the results include the the level of students' understanding and necessity of subject special services and subject special librarian, students' willingness to work as a subject special librarian, the willingness to put additional effort into equip themselves with competencies as subject special librarians. There were respondents who have equipped competencies as subject special librarians through courses provided by the department of Library and Information Science and school curriculum but have not done anything further. Respondents responded that there is a need to systematize special status system of subject special librarian and that subject specialty is important in implementing subject special services but that there is a lack of subject specialty. Based on the research results, this study suggests that there is a need to put more emphasis on developing curriculum that can help overcoming difficulties faced by students majoring in Information Sciecne and help them become competent subject special librarians.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.602-612
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• 2017

The purpose of this study was to identify employees' perception of social and economic values that social enterprises pursue and to provide implications for the training of social enterprise workers. The main results are as follows. First, more than half of the social enterprise workers recognized that economic value and social value were equally important. In addition, the responsibilities of realizing corporate social values were somewhat higher than those of employees. The social value of the social enterprise should be pursued in preference to the value for the company and its members. However, efforts to set goals for the social value of social enterprises were lacking. Second, social enterprise workers generally had a high perception of economic value and recognized that the responsibility and effort of management was more important than the employees in order to realize economic value. Third, the higher the age of workers, the higher the importance of social value than economic value, emphasized the responsibility of the manager, and the less the work experience, the more important is the social value and the manager's responsibility. While commercial enterprise workers are highly aware of the importance of economic value, non-profit enterprise workers are highly aware of the importance of social value. In the future, it will be necessary to provide an educational support program that allows workers to recognize the social and economic value of social enterprises in a balanced manner. Efforts are needed to develop, monitor and monitor standardized measures for measuring the value of social enterprises.

• The Journal of Art Theory & Practice
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• no.5
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• pp.197-215
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• 2007

Yangbanxi("model plays") symbolize the Cultural Revolution(1966~1976) in China. The Eight Model Revolutionary Works include five Chinese Modern Peking Operas, namely, Taking Tiger Mountain by Strategy(智取威虎山), Harbor(海港), Shaijabang(沙家浜), The Red Lantern(紅燈記), and Raid on the White Tiger Regiment ; (奇襲白虎團), ballets such as The Red Detachment of Women(紅色娘子軍) and The White-Haired Girl(白毛女) ; and a symphony: Shajiabang(沙家浜). On April 24, 1967, Chinese leaders, including Mao Zedong, saw a performance of The White-Haired Girl. Yanbanxi was performed in Beijing between May 24 and June 15 the same year. The Red Lantern was designated as a work for the proletarian classes by Jiang Qing(Mao Zedong's third wife and the most influential woman in China) and spread nationwide. It was also made into a film to be enjoyed by many people. The modern Chinese operas went a long way in their creation of visual images of revolutionary heroes. The Red Lantern, in particular, came to be regarded as the most representative revolutionary opera. In the course of such a process, Jiang Qing used Yangbanxi as a political tool for compelling the people to worship and pledge their allegiance to Mao in an effort to turn the Cultural Revolution into a class struggle on behalf of her husband. During the Cultural Revolution period, artists were made to associate with workers, farmers and soldiers based on the idea of advocating revolutionary arts for the proletarian classes. The characters in The Rend Lantern were portrayed as heroes from the proletarian classes according to the demands of the era. Chinese leaders set forth the principles of artistic expression, stressing three important factors: politics, heroes, and heroic acts, which were to be applied to all the visual arts, including Yangbanxi. This paper attempts to present a new view of fine arts during the Cultural Revolution in China by focusing on the productive significance of a leading style of a specific era in the past. To that end, this paper sheds light on products made in conformance with political instructions, stressing the importance of revolutionary heroes in The Red Lantern.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.422-427
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• 2010

Korean Game industry, especially MMORPG(Massively Multiplayer Online Game) has been rapidly expanding in these days. But As game industry is growing, lots of online game security incidents have also been increasing and getting prevailing. One of the most critical security incidents is 'Game Bots', which are programs to play MMORPG instead of human players. If player let the game bots play for them, they can get a lot of benefic game elements (experience points, items, etc.) without any effort, and it is considered unfair to other players. Plenty of game companies try to prevent bots, but it does not work well. In this paper, we propose a behavior pattern model for detecting bots. We analyzed behaviors of human players as well as bots and identified six game features to build the model to differentiate game bots from human players. Based on these features, we made a Naive Bayesian classifier to reasoning the game bot or not. To evaluated our method, we used 10 game bot data and 6 human Player data. As a result, we classify Game bot and human player with 88% accuracy.