• Journal of The Korean Association For Science Education
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• v.12 no.1
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• pp.35-46
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• 1992

The purpose of this study was to investigate the most effective teaching model in the study of boiling point elevation. The teaching models were classified into three group-deductive, inductive and analogical teaching models. Learning materials, based on three teaching models respectively, were applied to 11th grade students, and the effect of teaching models were investigated and analyzed. The average achievement score(4.24) of the group treated with the analogical teaching model was higher than those(3.06 respectively) of each group treated with inductive or deductive teaching model(p<0.001). Most students answered that the analogical teaching model was helpful and interesting one for the comprehension of scientific concept.

• East Asian mathematical journal
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• v.27 no.3
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• pp.319-337
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• 2011

We approximate a locally unique solution of a nonlinear equation in a Banach space setting using an inexact two-step Newton-type method. It turn out that under our new idea of recurrent functions, our semilocal analysis provides tighter error bounds than before, and in many interesting cases, weaker sufficient convergence conditions. Applications including the solution of nonlinear Chandrasekhar-type integral equations appearing in radiative transfer and two point boundary value problems are also provided in this study.

• Smart Structures and Systems
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• v.10 no.6
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• pp.547-555
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• 2012

Measuring crack length in concrete fracture test is not a trivial problem due to high speed crack propagation. In this study, mechanoluminascent (ML) material, which emits visible light under stress condition, was employed to visualize crack propagation during concrete fracture test. Three-point bending test was conducted with a notched concrete beam specimen. The cracking images due to ML phenomenon were recorded by using a high speed camera as a function of time and external loadings. The experimental results successfully demonstrated the capability of ML material as a promising visualization tool for concrete crack propagation. In addition, an interesting cracking behavior of concrete bending fracture was observed in which the crack propagated fast while the load decreased slowly at early fracture stage.

• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.657-664
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• 2006

The problem of reactivity oscillations for a point reactor constitutes an interesting aspect of nuclear reactor physics and its solution may give important information for dynamic and safety assessments. The present paper considers the problem of a reactivity oscillation for a source-driven system which involves some specific aspects that introduce significant differences with respect to the source-free situation. Assuming a square-wave shape for the reactivity insertion, the solution is derived by a fully analytical approach. The conditions for stability and instability can be identified in a straightforward way by directly studying the stationarity of the power response. Numerical results presented allow to discuss the role of the system kinetic parameters and of the time-shape of the reactivity wave.

• Database Research
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• v.34 no.3
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• pp.86-98
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• 2018

Point-of-Interest(POI) recommendation systems suggest the most interesting POIs to users considering the current location and time. With the rapid development of smartphones, internet-of-things, and location-based social networks, it has become feasible to accumulate huge amounts of user POI visits. Therefore, instant recommendation of interesting POIs at a given time is being widely recognized as important. To increase the performance of POI recommendation systems, several studies extracting users' POI sequential preference from POI check-in data, which is intended for implicit feedback, have been suggested. However, when constructing a model utilizing sequential preference, the model encounters possibility of data distortion because of a low number of observed check-ins which is attributed to intensified data sparsity. This paper suggests refinement of temporal intervals based on data confidence. When building a POI recommendation system using temporal intervals to model the POI sequential preference of users, our methodology reduces potential data distortion in the dataset and thus increases the performance of the recommendation system. We verify our model's effectiveness through the evaluation with the Foursquare and Gowalla dataset.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.4
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• pp.463-469
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• 2010

Since MOLA(Mars Orbiter Laser Altimeter) data, which provides altimetry data for Mars, does not cover the whole Mars area, image matching with MOC imagery should be implemented for the generation of DEM. However, automatic image matching is difficult because of insufficient features and low contrast. In this paper, we present the area based semi-automatic image matching algorithm with MOC-NA(Mars Orbiter Camera ? Narrow Angle) imagery. To accomplish this, seed points describing conjugate points are manually added for the stereo imagery, and interesting points are automatically produced by using such seed points. Produced interesting points being used as initial conjugate points, area based image matching is implemented. For the points which fail to match, the locations of initial conjugate points are recalculated by using matched six points and image matching process is re-implemented. The quality assessment by reversing the role of target and search image shows 97.5 % of points were laid within one pixel absolute difference.

• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.187-195
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• 2012

Smart phone allows advertisers to estimate customers behavior by selecting user context awareness information and gives users instant feed back about their behavior. Electronic equipments such as smart phone enable advertisers to advertise interesting product for each customers at the point of purchase. In this paper, we deal with the trends of Smart phone and internet based TV in the spotlight as the upcoming advertising media and propose the effective way of advertising, Smart Advertising model, which can give users advertising contents of their interesting product by collecting user context information from a variety of devices including N-screen in smart space. This model will induce modern people who live in flood of advertisements to buy products by providing interesting advertising contents.

• The Korean Journal of Applied Statistics
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• v.9 no.2
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• pp.145-159
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• 1996

We propose an adaptive searching method using some spatial relations among sample points to estimate the interesting area in the spatial population. The fundamental idea is to observe the neighboring sample points when a sample point is satified with some condition of an adaptive searching observation. For obseving the sample points with this method to estimate the area the sample size is decreased. From this result, we may expect to reduce the cost and time consuming in observation the sample points and to draw the shape of the interesting area without prior information of an spatial population. Some analytical simulation results are also presented.

• Korean Business Review
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• v.4
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• pp.339-354
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• 1991

Araditionally, a business enterprise was a unit of individual economy which looked after it's own interesting. This business philosophy gave not only much wealth and advantages to the society but also caused many social problems, such as pollution, inferior goods, false advertisements, unreasonable packing and so on. Because of this criticism, it is necessary for us to fulfill the social responsibility of business and to make an accounts report about it. A business should examine itself that, for the long run, the philosophy, looking after its own interesting by means of unreasonable economical actions, is unfavorable to the business and be aware of the social responsibility of business. It is important that the business accounting should identifying, measuring and communicating on the former business actibities, but in order to help the persons interested in the business in the with their interests control and their appraising the degree of social contribution, its object should be the embodiment of social justice by giving the economic intelligences. We con get at the root of formation of corporate social accounting on this point, that it to say, we can lay it down that business activities deal with the affairs which are measured, reported, and appraised from the social view points. Givena definition of this corporate social accounting according to the general standard of business accounting. I think the persons interested in business can get useful accounting informations to make a reasonable decision from the social view points. Set forth the responsibility of accounting based on this, it is very meaningful to study in the social recognition.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.130-135
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• 2000

In this study the vibration behavior of the stiffened double cylinder was experimently analyzed. Due to the complex structure of the double cylinder the outside cylinder frequency responses to the exciting forces applied on various posi-tions were analyzed by using spectrum analyzer in conjunction with an accelerometer and the natural frequencies were obtained. The technique of time-averaged holographic interferometry is applied to study the vibration characteristics of outside cylinder with stiffening T frame. The experimental data showed that the T frame had salient effect of damping on the testing structure at most of resonances. however the experimental results also revealed interesting phenomenon. At some particular frequencies the T frame. The experimental data showed that the T frame had salient effect of damping on the testing structure at most of resonances. However the experimental results also revealed interesting phenomenon. At some particular frequencies the T frame seemed to behave as a transmitter. In addition it has been successfully demon-started that optical method such as holographic interferometry is well suited for the identification of mode shapes. They can give us a whole-field non-contact measurement instead of the point-wise measurement by accelerometer in classical modal testing.