• Proceedings of the KSR Conference
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• 2002.10a
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• pp.349-356
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• 2002

This paper describes a mathematical programming model for constructing the rolling stock assignment plan. This plan is a schedule which assigns daily routings, maintenance activities, and other tasks to trainsets. A generalized set partitioning model which is a kind of integer programming model is suggested as a model for constructing the assignment plan. And a column generation method are suggested as a solution method.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.423-428
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• 2005

If the load of constructing vehicles during the construction work acts on the road or the ground surface on the soft ground, due to the excess stresses in soils the trafficability of the vehicles influences the constructing efficiency, constructing period and so on. Stress distribution in soils is the very important element to design and to solve the problems of settlement, safety of foundations and trafficability of constructing vehicle in civil engineering. This research represents the comparative estimation of the actual and theoretical measurement on the underground stress of outer layer for each soil after the observation of each top soil layer for its vertical and horizontal stress in (1)homogeneous sand ground (2) weak stratum with the sand soil (3) weak stratum with gravel of the soil model, and it also investigates the effect of subsidence of ground by the repeated load. The underground stress turn out to be different in the value of theoretical and actual measurement after the trial examination of model.

• Journal of Korean Elementary Science Education
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• v.31 no.1
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• pp.71-83
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• 2012

The purpose of this study was to explore ecological concepts, epistemological reasoning and reasoning processes through constructing 'food web and food pyramid' in ecology. We conducted classes which involved a 'food web and food pyramid' for $6^{th}$ grade students. Each class is constructed of small groups to do modeling and epistemological reasoning through communication. The researcher had videotaped and recorded each class and have made transcription about classes. We analysed patterns of 'food web and food pyramid models' and reasoning processes according to scientific epistemology using transcription data and student outputs. As a result, students represented phenomenon-based reasoning, relation-based reasoning and model-based reasoning in scientific epistemology from their modeling. Students usually did relation-based reasoning and model-based reasoning in food web which explains ecological phenonenon, while they usually did model-based reasoning in food pyramid which expects ecological phenomenon. Student's reasoning can be limited when they have misconception of scientific knowledge and are limited by fragmentary knowledge. This represents that students has to do relation-based reasoning and model-based reasoning is beneficial in their ecological model. It also suggests that students need to define correct-conception related to ecological modeling(food web, food pyramid).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1216-1222
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• 2002

In this study, we suggest structural plans for constructing local network economically and optimal broad local network coincided with regional characteristics in building broad local network - the most important factor in constructing broadband superspeed service digital network giving the consideration to broadband multimedia service unfolded in the future. For the purpose of constructing optimal superspeed local network, we made comparative study of the topology types of star and ring in various conditions from a economical point of view per node and with the transmission distance.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.325-330
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• 1999

Web-based simulation is one of the most interesting field of simulation research today. Among many research area of web-based simulation, we concern about what a effective way of building simulation model is since creating comprehensive simulation models can be expensive and time consuming. So this paper discusses how to integrate distributed simulation sub-models as objects for constructing the required simulation model which is more large and complex. We introduce two web-oriented methodologies (such as JIDL, CORBA) and the concepts of agent for assisting modelers to integrate simulation models scattered over the web. SINDBAD, which we designed, is a simulation environment which makes it possible constructing a simulation model with distributed model objects on the web and performing the parallel simulation in a distributed way. It is organized according to design patterns in the object oriented concept. Actually we are on the premise that all the distributed objects are originally composed in a CORBA-compatible way to start with our prototype of SINDBAD.

• Steel and Composite Structures
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• v.32 no.4
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• pp.537-548
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• 2019

This paper introduces an improved numerical model which can consider the bond-slip effect in steel-concrete composite structures without taking double nodes to minimize the complexity in constructing a finite element model. On the basis of a linear partial interaction theory and the use of the bond link element, the slip behavior is defined and the equivalent modulus of elasticity and yield strength for steel is derived. A solution procedure to evaluate the slip behavior along the interface of the composite flexural members is also proposed. After constructing the transfer matrix relation at an element level, successive application of the constructed relation is conducted from the first element to the last element with the compatibility condition and equilibrium equations at each node. Finally, correlation studies between numerical results and experimental data are conducted with the objective of establishing the validity of the proposed numerical model.

• Spatial Information Research
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• v.11 no.2
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• pp.185-201
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• 2003

The purpose of this study is to seek the methods of constructing a cultural information system based on GIS. It is impossible for regional culture to be formed apart from its surrounding space, so a study of culture should be based on realizing the features of its space. It is important to note that the elements composing a culture complicatedly interact with each other in their function and continuously change. Also they are interrelated in space and plentiful in their amount. Nevertheless, those studies practised so far in relation to culture and constructing cultural database are too limited in establishing cultural area or community life area required to recognize the regional identity So it is now essential that we should study the methods of cultural expression surpassing objective historical and cultural site maps instead of simple maps depicting historical remains or sites. From this viewpoint, this study tries to find various cultural phenomena in relation to their space through seeking the methods of constructing the cultural database model using XML. In addition, this study tries to construct a base for increasing the utilization of information in making the cultural contents.

• Journal of the Korean Operations Research and Management Science Society
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• v.10 no.1
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• pp.79-83
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• 1985

This purpose of this study is to suggest a tentative model for project selection of information system. In constructing a mathematical model, quantification of decision criteria is tried to lessen difficulties of measuring benefits of information system project. Suggested model enables us to select projects in the context of portfolio and information system policy.

• Proceedings of the Korean Statistical Society Conference
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• 2002.11a
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• pp.141-146
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• 2002

In this article we consider the problem of constructing confidence intervals for a linear regression model with nested error structure. A popular approach is the likelihood-based method employed by PROC MIXED of SAS. In this paper, we examine the ability of MIXED to produce confidence intervals that maintain the stated confidence coefficient. Our results suggest the intervals for the regression coefficients work well, but the intervals for the variance component associated with the primary level cannot be recommended. Accordingly, we propose alternative methods for constructing confidence intervals on the primary level variance component. Computer simulation is used to compare the proposed methods. A numerical example and SAS code are provided to demonstrate the methods.

• The Journal of Information Systems
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• v.15 no.1
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• pp.121-144
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• 2006

For constructing the purchasing decision-making model to maximize customer value on the electronic commerce, Means-Ends Network model was used for identifying means and fundamental objectives and their relationships were analyzed by the structural equation. A questionnaire survey of 481 customers in their internet shopping experiences was conducted to extract valid means and fundamental objectives' factors. As a result, 6 means objectives shopping travel, shipping errors, vendor trust, online payment, product choice, and recommender systems and 3 fundamental objectives-shopping convenience, internet ecology, and customer support were founded. Using these 9 factors, structural equation was analyzed 4 times to ensure statistical validities and to establish new interrelationships among them. The results showed that fundamental objectives are affected by the strong relationships within means objectives. This interrelationship with mens and fundamental objectives is interpreted as the purchasing decision-making model to maximize customer value on the electronic commerce in this paper.