• 한국디지털정책학회:학술대회논문집
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• 2007.06a
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• pp.79-87
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• 2007

This paper aims to offer a solution based on semantic document classification to improve e-Government utilization and efficiency for people using their own information retrieval system and linguistic expression Generally, semantic document classification method is an approach that classifies documents based on the diverse relationships between keywords in a document without fully describing hierarchial concepts between keywords. Our approach considers the deep meanings within the context of the document and radically enhances the information retrieval performance. Concept Weight Document Classification(CoWDC) method, which goes beyond using exist ing keyword and simple thesaurus/ontology methods by fully considering the concept hierarchy of various concepts is proposed, experimented, and evaluated. With the recognition that in order to verify the superiority of the semantic retrieval technology through test results of the CoWDC and efficiently integrate it into the e-Government, creation of a thesaurus, management of the operating system, expansion of the knowledge base and improvements in search service and accuracy at the national level were needed.

• 모자간호학회지
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• v.4 no.1
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• pp.80-90
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• 1994

Concept analysis is a strategy that examines the attributes or characteristics of a concept. It is a formal linguistic exercise to determine those defining attributes. The basic purpose of concept analysis is to clarify ambiguous concepts in theory, and to propose a precise operational definition which reflects the theoretical base of the concept. The concept of maternal role is too broad and variable in expression, therefore there has been no authentic definition nor standard opinion for this concept. The purpose of this study is to clarify the concept of maternal role which in turn will help in the development of a theory of maternal role attainment. In order to analyze the concept of maternal role, much effort was extended to look up "maternal role" in various dictionaries and literature, but only a few cases were found which listed this terminology. Consultation on the meaning of "mother" and "role" separately was then done and consequently a definition of "maternal role" was obtained through concept analysis of these two words independently, finding their attributes and unifying them. The attributes of the concept of maternal role which was analyzed based on the steps of concept analysis by Walker & Avant (1988) are : 1) Women who have pregnancies 2) Women who have a child 3) Women who rear a child 4) Expected behavior according to social status 5) Learning through social cultures 6) Social interrelationships. The antecedents of the maternal role are : 1) women who are pregnant and deliver a baby, must keep in contact with their child. 2) Circumstances for childrearing must be provided. 3) Formation of self-concept as mother should be developed, cognitive activity, which is necessary for the nurturing activity, financial support and preparation of childrearing should be provided. And the consequences of the maternal role are : 1) Improvement 2) Changeability 3) Ambiguity 4) Stability Through this concept analysis, the concept of the maternal role is defined as "expected behavior by social interrelationships and learned nurturing behavior through social cultures."

• Journal of the Korean Institute of Educational Facilities
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• v.22 no.2
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• pp.15-22
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• 2015

The latest educational curriculum in Korea started in 1997, and the 'Departmentalized Classroom System', which is a distinguishing modern concept compared with conventional pedagogy, has already been used in several high schools since 2009 and will be expanded to all middle school and high schools by 2014. However, most Korean schools are not yet physically ready to implement the new system. Moreover, despite many trials during the last three years, the characteristic and architectural function of a place called 'Home-base' is still vague and has caused many controversial arguments. In fact, a large number of home-base designs failed to accomplish their original task and there are counter evidences that shows reality was quite different over architect's personal and subjective radical plan. Therefore, this study seeks to introduce and objective scientific method based on an mathematical model of an optimized algorithm for planning a home-base area in a school design. The algorithm developed in this study is designed to determine the most efficient location for a home-base area to minimize the distance students typically need to walk.

• Structural Monitoring and Maintenance
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• v.10 no.3
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• pp.243-260
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• 2023

Indonesia has had seismic codes for earthquake-resistant structures designs since 1970 and has been updated five times to the latest in 2019. In updating the Indonesian seismic codes, seismic hazard maps for design also update, and there are changes to the Peak Ground Acceleration (PGA). Indonesian seismic design uses the concept of building performance levels consisting of Immediate occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). Related to this performance level, cases still found that buildings were damaged more than their performance targets after the earthquake. Based on the above issues, this study aims to analyze the performance of base isolation design on existing target buildings and analyze the seismic fragility for a case study in Indonesia. The target building is a prototype design 8-story medium-rise residential building using the reinforced concrete moment frame structure. Seismic fragility analysis uses Incremental Dynamic Analysis (IDA) with Nonlinear Time History Analysis (NLTHA) and eleven selected ground motions based on soil classification, magnitude, fault distance, and earthquake source mechanism. The comparison result of IDA shows a trend of significant performance improvement, with the same performance level target and risk category, the base isolation structure can be used at 1.46-3.20 times higher PGA than the fixed base structure. Then the fragility analysis results show that the fixed base structure has a safety margin of 30% and a base isolation structure of 62.5% from the PGA design. This result is useful for assessing existing buildings or considering a new building's performance.

• Journal of the Korea Society for Simulation
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• v.29 no.2
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• pp.63-72
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• 2020

Tank, which is a representative ground weapon system, is one of the most important weapon systems in each country. For the cost-effective acquisition of a tank based on scientific analysis, the operational concept and effectiveness should be studied based on engagement simulation technology. Besides physical capabilities including maneuver and communication, logical models including decision-making of a tank commander should be developed systematically. This paper describes a method to model a tank for engagement simulation based on Base System Model(BSM), which is the standard architecture of the weapon system model in AddSIM, an integrated engagement simulation software. In particular, a method is proposed to develop logical models by hierarchical and modular approach based on human decision-making model. The proposed method applies a mathematical formalism called DEVS(Discrete EVent system Specification) formalism. It is expected that the proposed method is widely used to study the operational concept and analyze the effectiveness of tanks in the Korean military in the future.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.677-688
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• 2008

In this paper, the general problem of impedance control for a robotic manipulator with a moving flexible base is addressed. Impedance control imposes a relation between force and displacement at the contact point with the environment. The concept of impedance control of flexible base mobile manipulator is rather new and is being considered for first time using singular perturbation and new sliding mode control methods by authors. Initially slow and fast dynamics of robot are decoupled using singular perturbation method. Slow dynamics represents the dynamics of the manipulator with rigid base. Fast dynamics is the equivalent effect of the flexibility in the base. Then, using sliding mode control method, an impedance control law is derived for the slow dynamics. The asymptotic stability of the overall system is guaranteed using a combined control law comprising the impedance control law and a feedback control law for the fast dynamics. As first time, base flexibility was analyzed accurately in this paper for flexible base moving manipulator (FBMM). General dynamic decoupling, whole system stability guarantee and new composed robust control method were proposed. This proposed Sliding Mode Impedance Control Method (SMIC) was simulated for two FBMM models. First model is a simple FBMM composed of a 2 DOFs planar manipulator and a single DOF moving base with flexibility in between. Second FBMM model is a complete advanced 10 DOF FBMM composed of a 4 DOF manipulator and a 6 DOF moving base with flexibility. This controller provides desired position/force control accurately with satisfactory damped vibrations especially at the point of contact. This is the first time that SMIC was addressed for FBMM.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.141-159
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• 2011

The purpose of the present research is to suggest implications on guidance of height concept understanding of figures by investigating concept understanding how sixth grade's elementary school students understand a height concept of figures. In order to achieve this research purpose, a height concept understanding test of figures was carried out with the target of 54 sixth grade students who already learned a height concept of plane figures and three-dimensional solid figures and thus this research analyzed characteristics and errors appeared there. When analyzing its characteristics and errors interviews with students were carried out for in-depth analysis. And as a result the following implications could be obtained. First, students felt more difficulty in measuring height in a figure that its lower base is not horizontal in questions measuring height of a plane figure. Second, there were cases that students associate a height concept of figures with experience of height experienced in daily life. Third, students were feeling difficulty in linguistically expressing a concept called height that oneself has. Expressing a concept linguistically plays an important role in understanding a concept clearly. Accordingly activities for raising this mathematical communication ability are required, Fourth, the present research can suggest implications in designing classes that students can clearly understand the height concept of figures.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.6
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• pp.291-299
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• 2014

There has been an increasing demand for introducing a base isolation system to secure the seismic safety of a nuclear power plant. However, the design criteria and the safety assessment methodology of a base isolated nuclear facility are still being developed. A performance based design concept for the base isolation system needs to be added to the general seismic design procedures. For the base isolation system, the displacement responses of isolators excited by the extended design basis earthquake are important as well as the design displacement. The possible displacement response by the extended design basis earthquake should be limited less than the failure displacement of the isolator. The failure of isolators were investigated by an experimental test to define the ultimate strain level of rubber bearings. The uncertainty analysis, considering the variations of the mechanical properties of isolators and input ground motions, was performed to estimate the probabilistic distribution of the isolator displacement. The relationship of the displacement response by each ground motion level was compared in view of a period elongation and a reduction of damping. Finally, several examples of isolator parameters are calculated and the considerations for an acceptable isolation design is discussed.

• Computers and Concrete
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• v.21 no.5
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• pp.495-504
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• 2018

The possibility of earthquakes in vulnerable regions indicates that efficient technique is required for seismic protection of buildings. During the recent decades, the concept is moving towards the insertion of base isolation on seismic prone buildings. So, investigation of structural behavior is a burning topic for buildings to be isolated in base level by bearing device. This study deals with the incorporation of base isolation system and focuses the changes of structural responses for different types of Lead Rubber Bearing (LRB) isolators. A number of sixteen model buildings have been simulated selecting twelve types of bearing systems as well as conventional fixed-base (FB) scheme. The superstructures of the high-rise buildings are represented by finite element assemblage adopting multi-degree of freedoms. Static and dynamic analyses are carried out for FB and base isolated (BI) buildings. The dynamic analysis in finite element package has been performed by the nonlinear time history analysis (THA) based on the site-specific seismic excitation and compared employing eminent earthquakes. The influence of the model type and the alteration in superstructure behavior of the isolated buildings have been duly assessed. The results of the 3D multistory structures show that the lateral forces, displacement, inertia and story accelerations of the superstructure of the seismic prone buildings are significantly reduced due to bearing insertion. The nonlinear dynamic analysis shows 12 to 40% lessening in base shear when LRB is incorporated leading to substantial allowance of horizontal displacement. It is revealed that the LRB isolators might be potential options to diminish the respective floor accelerations, inertia, displacements and base shear whatever the condition coincides. The isolators with lower force intercept but higher isolation period is found to be better for decreasing base shear, floor acceleration and inertia force leading to reduction of structural and non-structural damage. However, LRB with lower isolator period seems to be more effective in dropping displacement at bearing interface aimed at reducing horizontal shift of building structure.

• Structural Engineering and Mechanics
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• v.19 no.4
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• pp.381-399
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• 2005

Base isolation technologies have been proven to be very efficient in protecting structures from seismic hazards during experimental and theoretical studies. In recent years, there have been more and more engineering applications using base isolators to upgrade the seismic resistibility of structures. Optimum design of the base isolator can lessen the undesirable seismic hazard with the most efficiency. Hence, tracing the nonlinear behavior of the base isolator with good accuracy is important in the engineering profession. In order to predict the nonlinear behavior of base isolated structures precisely, hundreds even thousands of degrees-of-freedom and iterative algorithm are required for nonlinear time history analysis. In view of this, a simple and feasible exact formulation without any iteration has been proposed in this study to calculate the seismic responses of structures with base isolators. Comparison between the experimental results from shaking table tests conducted at National Center for Research on Earthquake Engineering in Taiwan and the analytical results show that the proposed method can accurately simulate the seismic behavior of base isolated structures with elastomeric bearings. Furthermore, it is also shown that the proposed method can predict the nonlinear behavior of the VCFPS isolated structure with accuracy as compared to that from the nonlinear finite element program. Therefore, the proposed concept can be used as a simple and practical tool for engineering professions for designing the elastomeric bearing as well as sliding bearing.