• 전기의세계
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• v.26 no.2
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• pp.66-71
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• 1977

A mathematical model, which can be used for the study of an influenza epidemic, was derived. The model of influenza takes into full consideration the incubation period and inapparent infection. That was analysed by means of digital computer under the conditions of changing the infection rate, .betha., from 4 to 5, for three types of communities (First type: the initial distribution of population, x$_{1}$(0)=89% susceptibles, x$_{2}$(0)=3% incubatives, x$_{3}$(0)=0.5% carriers, x$_{4}$(0)=7.5% immunes; Second type: x$_{1}$(0)=79%, x$_{2}$(0)=3%, x$_{3}$(0)=0.5%, x$_{4}$(0)=17.5%; Third type: x$_{1}$(0)=69%, x$_{2}$(0)=3%, x$_{3}$(0)=0.5%, x$_{4}$(0)=27.5%, considering the rate of population increase, in Seoul. In conclusion, the outcomes of this study are summarized as follow. 1) The new model is quite reasonable in representing many phenomena connected with influenza spread. 2) The more influenza does prevail, the smaller the valve of attack rate becomes, while the contagious period becomes slightly longer. 3) The average infection rate, .betha., of influenza is approximately 5 per week time and X$_{4}$(0) is about 27.5 percent of the total population in Seoul spring 1961. 4) The number of carriers of influenza in Seoul spring 1961 becomes maximum within approximately 2.4 weeks after the attack of diseases. 5) About 68 percent of all cases in the contagious period is infected with influenza from 5 to 15 days after the attack of diseases. The auther believes that the method to study the influenza models in this paper will be helpful to study the characteristics of other epidemics. It will also contribute to public healthe management and the preventive policy decision against epidemics.

• Computational Structural Engineering
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• v.4 no.4
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• pp.79-89
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• 1991

New design method of R/C slab system based on finite element method has been presented. The proposed method can substitute inaccurate existing method, which has limitation in its application, and provide accurate and efficient design results for any type of slab system. Isoparametric plate element used in the slab design has been efficiently formulated to save computational time. Reinforcement has been determined by strength design method and compared with code minimum values. Graphical output through comprehensive contour map for resulting moments and designed steel areas has considerably facilitated design process. Accurate shear results from isoparametric plate element enabled to check punching shear in a proper manner. In addition to strength design criteria, serviceability has also been checked by utilizing newly developed inelastic deflection multiplier method. An example for circular slab with opening showed that the proposed method could be applied to design of irregular slab without any difficulty.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.3
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• pp.246-256
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• 2005

Rule-based paradigm is one of the principal types of software process modeling and enaction approaches, as they provide formality and flexibility sufficient to handle complex processes. However, the systems adopting rule-based paradigms are hard to define and understand process models, and their inference engine should be modified or redeveloped at worst according to the change of process language. In this paper, we describe a rule-based PSEE(Process-Centered Software Engineering Environment) PRAiSE that solves the above limitations of existing rule-based PSEEs as well as maintains the merits of rule-based paradigm such as the ability to incorporate the nature of software processes flexibly in which dynamic changes and parallelism are pervasive and prevalent. PRAiSE provides RAiSE, a graphical Process modeling language, and defined process models are interpreted and enacted by process engine implemented using CLiPS, a rule based expert system tool.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.4
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• pp.371-377
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• 2009

In this paper, the dynamic characteristic of vibrating system which has translational and rotational degrees of freedom is studied. The moment of inertia of the system is modeled here as the inerter and the equivalent model to the system is proposed using dynamic stiffness method. It is shown that the size of inerter plays a major role to determine the dynamic characteristic of the system. This two degree of freedom system(DOF) is applied as a dynamic vibration absorber(DVA) to the elimination of single peak of main body. The solution for the undamped DVA is presented in analytical form while the damped DVA is designed using fixed point theory. The numerical examples are presented for verifying the methods.

• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.131-139
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• 2004

When calculating bearing capacity and settlement of actual foundation from plate test result fur design and construction of shallow foundation, scale effect should be considered. But, adequate guide and test result of scale effect were not prepared yet in Korea. So, to analyze the relations of bearing capacity and settlement as the difference of loading plate sizes, model test and field loading test were performed with different loading plate on weathered-granite layer. Model tests were conducted with water content, compaction number, saturated unit weight and plate size(Dl5, 25cm) in soil-box$(2,000\times 2,000\times 1,000mm)$ formed soil layer. Field loading tests were carried out with diameters of loading plate$(D15, 25, 30, 40, 75\times 75, 140\times 210cm)$ on the same soil condition. Finally, we presented the prediction formula of bearing and settlement for computating scale offset in design of shallow foundation through result analysis of load test and numerical simulation on weathered soil and rock.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.232-239
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• 2009

The prediction of the separation trajectories of external stores carried by military aircraft is an important task in the area of aircraft design having the objective to define the operational, release envelopes. This paper presents the results obtained for safe store separation from a fighter aircraft by experimental methods in the subsonic wind tunnel. The problems associated with separation of external stores can be studied by the use of several wind-tunnel test techniques. Attention is given the two most useful techniques: 1) dynamically scaled drop-model testing, 2) grid testing. A description of each method is given and data obtained are shown to validate the similarity within acceptable limits.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.40-50
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• 2002

In this paper, we present a GA(Genetic Algorithm) approach to select weighting matrices of an optimal LQ(Linear Quadratic) controller for SVC(Static VAR Compensator). A SVC, one of the FACTS(Flexible AC Transmission System), constructed by a FC(Fixed Capacitor) and a TCR(Thyristor Controlled Reactor), was designed and implemented to improve the damping of a synchronous generator, as well as to control the system voltage Also, a design of LQ controller depends on choosing weighting matrices. The selection of weighting matrices which is not a trivial solution is usually carried out by trial and error. We proposed an efficient method using GA of finding weighting matrices for optimal control law. Thus, we proved the usefulness of proposed method to improve the stability of single machine-infinite bus with SVC system by eigenvalues analysis and simulation.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1001-1014
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• 2003

In a feature modeling, problems such as ambiguities, interpretation errors, incompleteness, etc caused by informal specification occur in the modeling phase. Therefore, feature specification method and processes are suggested in this paper to resolve these problems. The structure and language of feature modeling is defined in this paper to specify various features. First, this feature model is abstracted in the meta-level to get predicates and attributes. Formal feature model specification method is proposed using multi-paradigm language. Second, Feature specification process is proposed to describe how to specify feature formally. And third, Feature interaction management is defined to solve the problems caused between specified features. Finally, the proposed feature specification method is applied to Distributed Meeting Scheduler System domain.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.421-431
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• 2018

The purpose of this study is to analyze the trends of 'traditional' terminology in Korea. We focus on an empirical investigation of how media reports are conveying 'tradition' terminology in our society by applying text mining and social network analysis techniques. The analysis covered 2,481,143 news articles related to 'tradition' terminology that appeared in the media since the 1920's. In this research, frequency analysis, association analysis and social network analysis were used on articles related to 'tradition' terminology from 1920 to 2017 by decade. By applying these data science techniques, we can grasp the meaning of social culture phenomenon related 'tradition' with objective and value-neutral position and understand the social symbolism which contains the tradition of the times.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.67-71
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• 2024

Mo Youzhi (1811-1871) was a famous scholar, poet and calligrapher in the late Qing Dynasty. Mo Youzhi's life was rich in experience and broad vision, especially during his ten years in the Shogunate of the Tsengoku Domain, and he made friends with many political and cultural elites. Mo Youzhi is talented and diligent, and has a good relationship with celebrities from all walks of life at that time, so that his talents have been fully demonstrated. In the Qing Dynasty, the study of calligraphy became the absolute dominant force in the world of calligraphy, and the first great prosperity occurred after the Qin and Han dynasties. In accordance with the times, Mo Youzhi devotes himself to learning, takes into account the calligraphy, and goes out on his own path. Moe's work seal, li, kai, line, especially fine seal. Based on its Lishu, this paper expounds its typical style and atypical style respectively, and also discusses the relationship between its Lishu and other fonts. Finally, the author briefly summarizes the significance of Li Shu for the creation of contemporary Li Shu.In the course of discussion, always based on calligraphy ink, consult the relevant literature, combined with Mo Youzhi's life experience, try to be objective and fair, the listed points of view can be based on.